Phục hồi và phát triển giống lúa đặc sản Nanh Chồn tại tỉnh Bà Rịa - Vũng Tàu

so
KHCN BA
RIA
- YUNG TAU VIEN KHKT NONG NGHIEP MIEN NAM
BAO CAO KET QUA
THI/C
HIEN DE TAI
NGHIEN
Ciru
PHAT TRIEN KHOA HOC CONG NGHE
Ten ae
tai:
PHUC HOI VA PHAT TRIEN GI6NG LUA DAC SAN
NANH CHON TAI TINH BA
RIA
- VUNG TAU
•
Co-
quan chu quan:
So"
Khoa hoc Cong nghe Ba
Rja-Vung
Tau
•
Co*
quan chu
tri:
Vien Khoa hoc Ky thuat Nong nghiep mien Nam
. Chu nhiem de tai: TS. Do
Kh5c
Thjnh

.
Then
gian thyc hien: 2005 - 2008
Ba Rja - Vung Tau
Thang 5/2009
^//^/l^^
so
KHCN BA
RIA
- VUNG TAU VIEN KHKT NONG NGHIEP MIEN NAM
BAO CAO
KET
QUA
THl/C
HIEN DE
TAI
NGHIEN
CUtf
PHAT TRIEN KHOA HOC CONG NGHE
Ten ae
tai:
PHVC HOI VA PHAT TRIEN
GIONG
LUA DAC SAN
NANH CHON TAI TINH BA RIA - VUNG TAU
•
Co"
quan ehu quan:
So"
Khoa hoc Cong nghe Ba Ria-Vung Tau

•
Co"
quan chu tri: Vien Khoa hoc Ky thuat Nong nghiep mien Nam
• Chu nhiem de tai: TS. Do Khac Thinh
• Tham gia thyc hien:
Dd Khdc Thinh,
Ddo
Minh So, Nguyin Hudng
• Cong tac thyc hien:
-
Trung
tam
Khuyin nong
tinh
BR-
VT
-
HTX
An
Nhat,
huyen
Long
Diin,
tinh
BR-VT
-
Vien
lua
DBSCL
.

Then
gian thyc hien: 2005 - 2008
Ba Rja - Vung Tau
Thang 5/2009
MUC LUC
• •
1.
Dat van de 1
2.
Tong quan tai lieu
2
2.1
Bao tdn ngudn gen
liia
dac san tren
thi
gidi 2
2.2 Bao tdn ngudn gen
liia
dac san d Viet Nam 4
2.3 Nghien
ciiu
va danh gia dac tinh gidng
liia
dac san 6
2.4 Anh hudng cua mdi trudng
din
nang
suit,
phim chit

gidng
liia
dac san
^2
2.5 Chgn
Igc
ddng thuan va phuc trang gidng
liia
dac san
17
3.
Muc tieu cua de tai 18
4.
Noi dung va
phu-ong
phap thyc hien
^
4.1
Ndi
dung 18
4.2 Phuong phap thi nghiem
18
5. Ket qua thyc hien
5.7 Dieu tra hien trang sdn xuat lua vd khdo
sdt,
thu thap ngudn
vat
lieu
liia Nanh Chon '. ' ' 20
5.1.1 Khao sat chgn diem viing nghien

ciiu
20
5.1.2 Thu thap ngudn vat lieu nghien ciru 22
5.1.3
Dieu tra hien trang san xuat 22
5.2 Thanh
Ipc,
phuc
hoi
giong liia
Nanh
Chdn 27
5.2.1 Ket qua thuc hien nam 2005 27
5.2.2 Ket qua thuc hien nam 2006
31
5.2.3 Ket qua thuc hien nam 2007 38
5.2.4
Kit
qua thuc hien nam 2008 43
5.2.5 Tdm tat dac diem gidng
liia
Nanh Chdn tinh Ba Ria - Viing Tau 46
5.3 Xdc dinh cong
ihiec bon
phan phit hap cho liia
Nanh
Chdn 47
5.3.1
Kit
qua thuc hien nam 2007 47

5.3.2
Kit
qua thuc hien nam 2008 48
5.3.3 Nhan xet
kit
qua thi nghiem cdng thiic phan bdn 49
5.4 Hoan thien QTKT
vd chuyen
giao kit qua de tai 50
5.4.1
Thir nghiem md hinh san xuat 50
5.4.2 Hgi thao thuc dja 51
5.4.3 Xay dung va chuyen giao qui trinh san xuat 52
6. Ket
luan
va de nghi 53
TAI
LIEU
THAM KHAO 55
Phu luc
1
(Cac bang sd lieu) 60
Phu luc 2 (Qui trinh ky thuat) 67
Phu luc 3 (Lg trinh xay
dimg
chi
din
dia ly) 71
Phu luc 4
(Baocaokit qua

dieu
tra
san xuat liia) 72
Phu luc 5
(Mgt sd
hinh anh thirc hien de tai) 82
PHUC HOI VA PHAT TRIEN GIONG LUA DAC SAN NANH CHON
TAI TINH BA
RIA
- VUNG TAU
Do Khdc
Thinh,
Ddo Minh So vd Nguyin Hudng
1.
DAT VAN
DE
Cuge
each
mang xanh da dugc tiln hanh tir nhung nam 60 ciia
thi
ky trudc, da dat
dugc nhumg thanh tuu to
Idn
trong viec tang nang
suit
cay trdng, trong dd ddi vdi san
xuat lua
rit
dang ghi nhan.
Sir

thay
thi
cac gidng
liia miia
truyin thdng dai ngay cao
cay, nang suat thap
bing
cac gidng cao san
ngin
ngay lam co sd cho viee
dlu
tu phan
bdn, thuy
Igi,
.v.v. dl tham canh, tang vu. Tuy vay cung
cin
danh gia mat trai cua each
mang xanh, dd la su mat mat ngudn gen
liia
dia phuong cd truyin vdi hang nghin gidng,
trong do cd nhimg gidng
liia
thom,
liia nip
dac san. Nhirng gidng nay cd nhirng dac tinh
quy ve chat lugng thom ngon, hoac tinh chdng chju vdi dilu kien
bit
Igi.
Vl
thue trang

ngudn gen cay
liia
d Viet Nam, da phan dien tich san
xult liia miia
truyin thdng da bi
thay the bang cac gidng cai thien ngan ngay, dac biet la d cac viing ddng
bing,
noi cd
he thdng thuy loi phat trien.
Hien nay nhu cau gao dac san, chat lugng cao cua ngudi tieu dimg trong va
ngoai
nude
cd xu hudng ngay cang gia tang. Tuy vay viec san xuat lua gao dac san
vln
chua dap iimg nhu cau tieu diing trong
nude
trong khi chi phi san xuat cdn cao. nang
suat thap va chat lugng giam. Do gidng dugc san xuat lau ddi va tap quan sir dung
liia
an lam gidng cua ngudi san xuat nen hau het cac gidng lua dac san dia phuang deu bi
thoai hoa va lan tap. Ben canh do, cac gidng dia phuong thudng cd tinh thich nghi hep
ve dia ly nen khdng the ap dung chung qui trinh ky thuat theo nhdm gidng. Nhieu gidng
liia dac san da khdng dugc san xuat trong thdi gian dai, mdt sd gidng gan nhu bj tuyet
chung, can dugc phuc hdi lai. Nhiing trd ngai neu tren rat can dugc hd trg eua cac nha
quan ly, nha khoa hgc va cac doanh nghiep.
Trong
nhdm'
gidng lua dac san Nam Bd trudc day thi Nanh Chdn la gidng dugc
trdng phd bien d cac viing trdng
liia ciia

tinh Ba
Ria-VQng
Tau (BR-VT). Giong rat ndi
tieng ve pham chat va
miii
vj, dugc xem la mdt trong nhirng loai gao ngon nhat d cac
tinh phia Nam nen cd gia trj thuong mai cao, nhat la thdi ky trudc nam 1980. Do canh
tac lau ddi, gidng Nanh Chon
chii
yeu d huyen Long Dat da bj lan tap sinh hgc, d vai
noi gidng cd hat to, thang va dai hon nhung vj nggt, do xdp cua com da bj giam nhieu
hoac cd ciing ten la Nanh Chdn nhung lai la gidng khac. Do vay, viec khdi phuc va phat
trien gidng
liia
dae san Nanh Chdn
ciia
tinh BR-VT cd y nghTa cap
bach,
thiet thuc va
lau dai nham nang cao hieu qua san xuat
liia,
dap
ling
nhu cau cua ngudi tieu diing va
phuc vu cho cdng tac du ljch
ciia
tinh nha.
2.
TONG QUAN TAI LIEU
2.1 Bao ton nguon gen lua dac san tren the gidi

Theo djnh nghia cua Ceng Y. W., Cheng Y. va Dai L. Y. (1998), R. C.
Chaudhary va Dat T. V.
(2001),
liia
dac san la nhiing loai
liia
dac biet, khdng gidng
nhu cac loai
liia
phd bien thdng thudng. De danh gia
liia
dac san, ngudi ta dua vao
nhirng chi tieu quan trgng quy djnh chung cho phan
Idn
cac nude Chau A, Chau Phi
(Uneneverh et al, 1992; Juliano & Villareal, 1993) nhu hinh dang, kich cd, ham lugng
amylose, mau ndi nhii va
miii
thom. Theo dd nhiing loai
liia
cd
sir
khac biet vl mdt vai
dac diem tren nhiing chi tieu quan trgng quy djnh chung se dugc
xip
vao
liia
dac san.
Nang suat, gia trj sir dung, each che bien cac loai
liia

gao dac san khac nhau va ciing
khac cac loai
liia
thdng
thudng.
Liia
nep, lua deo,
liia
thom,
liia
mau
(liia
do,
liia
tim, lua den),
liia
nuong
japonica,
liia
che bien dd uong,
liia
chuyen nau rugu,
liia
cd pham chat dinh dudng cao
va
Ilia
lam
thiic
an gia sue (feed rice) deu thugc nhdm
liia

dac san. Khai niem ve
liia
dac
san cd truyen,
liia
dac san cai tien la khai niem de phan biet
liia
dac san ban dja va liia
dac san chgn tao, cai tiln (Ceng Y. W., Cheng Y. & Dai L. Y., 1998; Chaudhary & D.
V. Tran, 2001; S. Tang & Z. Wang, 2001). Ciing cd tac gia xep
liia
dai thugc
liia
dac
san (Tran van Dat, 2002). Nhin chung su xep loai ve
liia
dac san chi mang tinh tuong
ddi,
nhung khai niem ve
liia
dac san la loai
liia
dac biet khdng gidng nhu cac loai
liia
thdng
thudmg
la khai niem kha thdng nhat. Tai ngan hang gen qudc gia Trung Qudc
(Vien Han lam Khoa hgc Ndng nghiep Trung Qudc - CAAS) dang bao quan 64.269
mau gidng
liia,

trong dd cd khoang 10% la cac gidng
liia
dac san, bao gdm gidng
liia
thom, liia nep, lua mau,
liia
gao deo, lua chuyen nau rugu (Tang and Wang, 2001;
Zhong and Ying, 1997).
6
An Do, cd khoang 70.000 mau gidng
liia
dugc luu giir tai cac vien nghien ciru
va cac trudng dai hgc, trong dd tai DRR va CRR da cd 800 mau gidng lua thom va tai
trung tam HAU cd 400 mau gidng
liia
thom (Singh et al.
2001).
Liia
dd dugc phan bd d nhieu nude Chau A (Juliano & Villareal, 1993). O vimg
Tay Nam va Ddng Trung Qudc phan
Idn liia
dd thugc loai indica. Theo sd lieu nam
1990 cua Ngan hang Gen Cay trdng tai
BIC
Kinh, trong sd
31.663 mlu
gidng
liia
cd
20,7%

Ilia
do. Cac gidng
liia
dd dja phuong cd tinh chdng chju cao ddi vdi mdi trudrng
bat
Igi
nhu dat can cdi, dat mii cao.
Liia
den ciing la loai
liia
dac san dugc tim thay d nhieu
nude
Chau A. Trung
Qudc (62%) la nude cd ngudn
liia
den phong
phii
nhit,
tiep den la Srilanka (8,6%),
Indonesia (7,2%), An Do (5,1%), Philippines (4,3%) va Bangladesh (4,1%). Ty
phin
cdn lai la cua cac nude Malaysia, Thai Lan. Myanma, Viet Nam (Chaudhary R. C. va
D.T. Van, 2001).
Tai Lao tir nam 1995-1998, du an hgp tac bao tdn ngudn gen cay
liia
giua bg
Ndng nghiep Lao vdi Vien Nghien
ciiu
Lua Qudc tl
(IRRI)

da thu thap dugc 12.555
mlu
gidng lua ed truyen, trong do 85,9% la
liia nip
(Appa Rao et al
1999).
CJ Campuchia hien cd
rit
nhilu gidng lua thom dja phuong, bao gdm cac gidng
liia nip
va
liia
thom dugc gieo trdng trong san xuat tai cac viing sinh thai khac nhau.
Trong sd 3.400 gidng liia cd truyin dugc phan tich, cd den 6% la
liia
thom (M. Sarom,
2001).
Trung tam Tai nguyen Di truyen Thuc vat Viet Nam dang bao quan hon
5.000
mau gidng
liia
dja phuong cua Viet Nam, trong do cd khoang
1.200
mau gidng
liia
nep
cd truyin (Nguyen Hiru NghTa,
Biii
Chi Bim, Luu Nggc Trinh, Le VTnh Thao,
2001).

Trong
711
gidng
liia
dja phuong mien Bac Viet Nam da dugc xac djnh cd 68 gidng
liia
thom, chilm 9,6%. Trong 577 gidng
liia
japonica d phia Bac Viet Nam cd 363 gidng
Ilia
nuong, chilm 62,9% (Nguyen Thj Quynh, 2004).
San pham cua cac gidng
liia
dac san rat da dang. Tir xa xua, nd da dugc diing
lam luong thuc, thuc pham dac biet cua timg dan tdc trong nhirng djp hdi he, le tet, cudi
hdi.
Banh tnmg, banh day, banh khao, banh com, com tam, rugu can, xdi va
nigu
nep la
nhirng san pham cua
liia
dac san tdn tai tir lau ddi trong cdng ddng cac dan tdc Viet
Nam.
Mdt vai gidng
liia
thom Basmati hoac Jasmine cd
miii
thom kha dac
thii,
dugc

diing trong cdng nghe che bien lam nhirng san pham dac biet cd
miii
thom chocolate
(Chaudhary R. C. va D. V. Tran, 2001).
Gao mau thudng dugc diing trong nhumg le hdi
Idn
va trong cdng nghiep che
bien thuc pham. Nd cdn diing lam eae loai banh va cac loai my sgi. Banh nggt va rugu
mau lam tir
liia
mau thudng dugc bay dgn ciing vdi nhiing loai thiic an khac vao dip le
tet. Thuc pham mau den tu nhien thudng dugc ggi la "thuc pham den" rat dugc ua
chudng d Trung Qudc.
"Rugu
Nip
Mdi" ciia miln
BIC
Viet Nam, rugu
"Nip
Than Gd Den" cua tinh
Long An, hay "Rugu
liia
Vang" cua tinh
Trilt
Giang, Trung Qudc deu dugc lam tir gao
nep,
la nhumg loai rugu truyen thdng kha ndi tieng.
CI
An Do va Pakistan nhu
clu

vdi
liia
thom Basmati chat lugng cao da tang len
mdt each dot nggt: Nhimg ngudi dan Chau A d cac nude Chau Au, Chau My, Trung
Ddng cd nhu cau
Idn
va cd kha nang ve tai chinh de mua cac loai gao Basmati, Jasmine
chat lugng tdt nhat vdi gia cao. Do vay, viec gieo trdng va kinh doanh cac loai gao nay
da dem lai
Igi
nhuan
Idn
hon nhieu so vdi cac loai gao khac. Tinh hinh ciing xay ra
tuong tu vdi cac loai gao
nip,
gao deo, gao nau rugu. Gia ca tren thj trudng cua cac loai
gao nay thudng cao hon
50%i
so vdi cac loai gao thdng thudng. Nhu cau ngay mdt tang
va tang dot nggt thudng
thiy
trong
xult khiu
gao loai nay d Thai Lan, Campuchia, va
Lao (Chaudhary R. C. va D. V. Tran, 2001). Cac gidng lua thom ngay cang trd nen hap
dan d
nude
My, nhat la tir 10 nam
gin
day. Cac gidng nay,

chii
yeu la Jasmine va
Basmati cua Thai Lan, da chiem den
11
% lugng gao an nhap khau cua
nude
My
(USAD,
1994). Lugng gao lua thorn nhap
khiu
vao
nude
My tang tir con sd 0 trong
nam 1980, len 400.000
tin
trong nam 1997 (J. N. Rutger et al. 2001).
Ngudn tai nguyen di truyen
liia
dac san cua Viet Nam va the gidi la vd ciing
phong
phii.
Day la mdt trong nhirng ngudn tai nguyen thien nhien quy gia
ciia
nhan loai
va la
CO
sd vat chat quan trgng cho cdng tac cai thien cac gidng
liia
mdi ( Tang, Wang,
2001;

Chang va Somrith, 1979).
2.2 Bao ton nguon gen lua dac san
a
Viet nam
Ngudn gen
liia
dac san phd bien d Viet Nam la
liia
nip,
liia
nuong va
liia
thom.
2.2.1 Nguon gen
lua
nep
Hien nay, Ngan hang gen Qudc Gia tai Vien Khoa hgc Ky thuat Ndng nghiep
Viet Nam dang bao quan
1.200
mlu
gidng
liia nip
truyin thdng ban dja dugc thu thap
tren toan qudc. Trong
nhiimg mlu
gidng nay
gin
200
mlu
gidng da dugc thu thap trudc

nam 1990, la nhirng gidng
chii
yeu cd ngudn goc
liia
rudng d khu vuc ddng
bing,
cdn
lai hon 1.000 mau gidng dugc thu thap sau nam 1990 d khu vuc miln mii (NghTa &
CS.,
2007). Ngudn gen di truyen
liia
nep d khu vuc miln mii cua Viet Nam la
rit
giau
cd va da dang, do nhieu nhdm dan tdc sir dung
liia nip
lam ngudn luong thuc chinh.
Liia
nep dugc tieu dimg d mien mii nhieu hon d ddng bang. Mdt vai nhdm dan tdc nhu
dan tdc Thai cd tap tuc gdi com nep ra ddng cho ca gia dinh an trua. Uu
thi
cua mdn
nay chi can nau mdt lan trong ngay cd the bao quan sudt ca ngay khdng bj hdng, com
nep an no lau.
Liia
nep d khu vuc mien nui va ddng bang Bac Viet Nam la
liia
japonica
nhieu hon
liia

indica. Nhirng gidng
liia
nep ndi tieng d viing nay deu cd dang hat trdn,
bau, thich nghi vdi canh tac
liia
nuong va ca
liia
nude (NghTa, 2007).
Liia
nep d khu vuc
mien
niii,
cd nhieu gidng hat
Idn,
khdi lugng
1000
hat >
37g,
dugc gieo trdng d viing
ddi nui
giOra
Viet Nam va Lao, do ddng bao mien
niii
bao tdn qua nhieu the he.
C)
khu
vuc mien
niii,
liia
nep dugc gieo trdng ehinh trong vu

miia
ea d nuong ray va rudng
nude.
0 khu vuc ddng bang
liia
nep chi dugc gieo trdng d rudng
nude
trong vu
miia
va
ea trong vu chiem xuan vdi dien tich nhd hon. Nep chiem xdi kem deo, pham chat kem
hon so vdi nep
miia.
Liia nep d khu vuc ddng bang Bac Viet Nam dugc danh gia la deo
va ed mill rat thom nhu cac gidng nep Cai, nep Hoa Vang, nep Quyt, nep Mo.
Nha bac hgc Le Quy Ddn (sdng d the ky
18),
trong cudn
"Phii
bien Tap luc" da
md ta nhiing gidng
liia
nep trdng d khu vuc bd bien mien Trung Viet Nam nhu nep Ky
Lan, nep Suat, nep Hat Cau, nep Huong Bau, nep Ong Lao, nep Trau, nep Bd, nep Mit,
nep Rau, nep Mang,
nip
Ngira
(Biii
Huy Dap, 1980). Mdt vai gidng nay cdn tdn tai den
ngay nay.

C>
khu vuc ddng
bing
Nam Viet Nam,
liia nip
it da dang hon, da phan dang hat
dai,
thom va it dinh hon,
tit
ca la ngudn gen cua
liia
indica (N. H. NghTa, B. C. Bim, L.
N.
Trinh,
2001).
Nhilu gidng
nip
ndi tilng cua khu vuc nay la
nip
Mudp, nep May,
nep Than,
nip
Sap,
nip
Tau Huong,
nip
Mdng Chim, nep Md. nep cd Ngdng, nep Bd
Cau, nep Ba Tap va nep Dd (B. C. Bim va N. T. Lang, 2002).
2.2.2 Nguon gen lua
thom

Trung tam Tai nguyen Di truyin Thuc vat Viet Nam dang bao quan hon
5.000
mau gidng
liia
dja phuong, dugc suu tap tir nhumg viing khac nhau ve dia hinh, khi
hau.
dja ly, tap quan canh tac, dan tdc, ljch sir trdng
liia,
trong dd cd tap doan gidng
liia
thom. Phan loai ngudn gen
liia
dja phuong phia Bac Viet Nam cho
thiy
trong
711
gidng
cd 68 gidng lua thom, chilm 9,6% tap doan nghien
ciiu
(Quynh, 2004).
Sir
da dang va
dac sac
ciia
ngudn tai nguyen di truyen
liia
thom cd truyin Viet Nam dugc
thi
hien
dly

dii
cac net dae tnmg d cac tinh
phiaBlc.
Tai viing sinh thai nay,
liia
thom cd the
bag
gdm ca 3 loai:
liia
Tam,
liia
nep va lua nuong vdi
dly dii
ca 2 loai hinh indica va
japonica (NghTa, Buu, Trinh & Thao, 2001). Dae biet da xac djnh dugc mdt
phin liia
Tam thom (gao te) phia
BIC
Viet Nam thugc loai hinh japonica (Trinh et al. 1995; Trinh
1999;
Siiu
1999; NghTa & Trinh, 2000.)
O mien Nam, cd khoang 2.000 mau gidng
liia
dja phuong dugc suu tap va bao
quan, trong dd cd cac gidng
liia
thom va nep thom. Hau het cac gidng lua thom Nam Bg
cd dang hat dai, thon dai thude loai hinh indica. Cd nhieu gidng
liia

thom d cac viing
sinh thai khac nhau, nhung ve thdi gian sinh trudng hoac mirc do phan img
v.di
quang
chu ky cd the phan loai thanh 3 nhdm:
miia
sdm,
miia
lo va
miia
mudn. Ndi tieng nhat
la gidng Nang Thom Chg Dao d Can Dude, Long An phan img chat vdi quang chu ky
anh sang cd thoi gian sinh tnrdng
165-175
ngay, cao cay
150-160
cm. Gao ed vet
due or
giira ggi la "hat luu". Com xdp deo, cd
miii
thom nhat la sau khi nau. Tuy vay trong
thdi gian gan day, theo danh gia
ciia
nhieu chuyen gia va ngudi dan san xuat
liia,
miii
thom eua gao Nang Thom Chg Dao da bj giam nhieu. Cd nhieu ly do giai thich van de
nay. Nguyen nhan cd the do gidng da bj thoai hda, hoac do ngudn nude tudi da hi thay
ddi,
bdn phan bdn vd eo nhieu cung bj anh hudmg. Cd mdt sd ngudi cdn cho rang do

che do dinh dudng ngay nay ciia ngudi dan da dugc cai thien nhieu nen cam giac ngon
mieng ciing nhu cam quan ve
miii
thom com gao ciing bj giam tuong ddi.
Liia
thom d viing Tay Nguyen chu yeu trdng tren nuong ray, ed dang bdng to,
khdi lugng
1000
hat thudng
Idn
hon 25g, thdi gian sinh trudng
110-140
ngay, than cao,
nhung chdng dd kha tdt, nang
suit
dat 1-2,5 t/ha (Thuy 1998, Arraudeau va Xuan,
1995) va
phin Idn
thugc loai hinh indica, chilm
81%
(NghTa va CS, 2007). Theo NghTa
va CS. (2007), cd mdt sd
mlu
gidng thu thap d Tay Nguyen cd kha nang chdng chju
khd han, benh Dao On va benh Bac La.
2.2.3 Nguon gen lua cam
Liia
dm la loai
liia
mau, cd the la mau dd, mau tim hoac den.

Liia
cam ed nhieu
d cac nude Chau A (Juliano & Villareal, 1993; Tang 1995).
6
Viet Nam da thu thap va
bao quan hon 100 mau gidng
liia elm
(Quynh, 2002).
Liia elm
cung la loai lua dac san
cua Viet Nam, ngoai lam thuc
phim
nd cdn la vat
phim
ciing tl theo muc dich tdn giao,
nd cdn la san
phim
lam
thude,
dinh duong chirc nang. Phan loai theo loai com gao va
viing san
xult
cd cac loai: lua cam te, dm
nip,
dm nuong va cam rudng (NghTa,
2007).
Thuc tl
phin Idn
lua dm dugc trdng d viing trung du mien nui vdi dien tich gidi
han, it dugc trdng d viing ddng bang.

2.3 Nghien cuu di truyin va danh gia cac dac tinh giong lua dac san
2.3.1 Danh gia di truyen nguon gen lua dac san
Dieu tra tinh hinh su dung cac gidng
liia
nam 2000-2001 do Trung tam Khao
Kiem nghiem Gidng Cay trdng Trung uong cho thay: mac
dii
nhieu dja phuong tap
trung gieo trdng cac gidng liia tham canh, nang suat cao nhung ty le gieo trdng gidng
liia
dac san van cdn
Idn,
chiem
18,90%
tren tdng sd gidng
liia
dang dugc
sii
dung trong
san xuat hien nay. Dieu nay cho thay ngudn gen
liia
dac san dang sir dung d cac viing
sinh thai cdn rat phong
phii
va da dang. Trong 3 viing dieu tra thi eae tinh thanh phd
phia Bac cd
sir
da dang hon va chiem ty le cao hon (29,6%) so vdi viing Duyen Hai
Nam Tmng Bd, Tay Nguyen (12,5%) va Nam Bd (12,1%) (NghTa va CS., 2007). Viing
cac tinh phia Bac, viing Tay Nguyen va Nam Trung Bd cd ngudn gen

liia
dac san trong
vu
Miia
va He Thu cao hon (36,0 va 16,9%) so vdi vu Ddng Xuan (22,2
8L
6,9%) do
or
day cdn diing nhieu gidng dac san cd truyen, nhat la gidng phan
ling
anh sang ngay
ngin
(NghTa
«&
CS., 2007).
Rieng viing cac tinh thanh Nam Bd cd ngudn gen
liia
dac san trong vu Ddng
Xuan cao hon (14,4%) so vdi
liia
He Thu (9,9%) do viing nay dang
sii
dung nhieu
gidng
Ilia
thom cai tien nhu Jasmine, OM 3536,
ST
1,
ST3, VD20.
2.3.2 Danh gia da dang di truyen

Bing
phuong phap SSR (Simple Sequence Repeats) va phan mem NTSYS de
phan nhdm cac gidng
liia
theo khoang each di truyen. Nghien curu cua Vien
Liia
DBSCL da tiln hanh vdi 46 gidng
liia
thom dja phuong tren co sd phan tich 8 loci khac
nhau thugc 3 marker SSR lien
kit
gen
miii
thom (RM 223, RM 150 va RM 190).
Kit
qua cho
thiy
cac gidng
liia
thom cho bang hinh kha rd. Marker RM 223 trong sd 3
marker lien
kit
gen
miii
thom cho sd bang da hinh cao. Cd
thi
phan chia cac nhdm di
truyen theo
miii
thom nhu sau:

*Nhdml:
- Khao Dawk Mali, Nang Thom Chg Dao cd khoang each di truyin lien
kit
vdi
gen
mill thom gidng nhau d muc dung hgp
100%
(Lang
«&
CS. 2002).
- Nhd thom, Nang Nhen Thom cd khoang each di truyin lien
kit
vdi gen
miii
thorn
ciing gidng nhau.
* Nhom 2: Cd 2 nhdm phu vdi khoang each di truyin d mirc do dung hgp
Idn
hon 70%,
cac gidng trong ciing nhdm cd
miic
do dung hgp
Idn
hon 85%.
*
Nhdm 3: Cd 2 nhdm phu vdi khoang
each
di truyin d mirc do dung hgp
Idn
hon 75%.

*
Nhdm 4: Cd 2 nhdm phu vdi khoang
each
di truyin d mirc do dung hgp
Idn
hon 70%.
Theo
kit
qua danh gia nay gidng Nanh Chdn dlu cd mat d 3 nhdm di truyen:
Nanh Chdn 3 d nhdm 2; Nanh Chon
1
va Nanh Chdn 2 d 2 nhdm phu cua nhdm
1.
Dieu
nay chimg td cac
mlu
gidng Nanh Chdn cd ngudn gdc chgn lge tuong ddi khac nhau,
dac biet la vl tinh thom.
Ket qua nghien cuu tren day khdng chi neu len
sir
da hinh kieu gen cua ngudn tai
nguyen
liia
thom d DBSCL ma edn md ra hudng
lira
chgn vat lieu khdi dau trong cdng
tac cai tien
liia
thom. Nguyen tac quan trgng
lira

chgn bd me trong cac cap lai la ed su
tuong phan
Idn
hay cd khoang
each
di truyen cang xa nhau thi mirc do da dang di
truyen d ddi sau cang cao, kha nang chgn lge gidng mong mudn cang
Idn.
2.3.3 Da dang di truyen giong dac san va cong dong cac dan
toe
Cdng ddng cac dan tdc thieu sd thudng sdng tap trung chu ylu d khu vuc miln
mil Viet Nam. Luong thuc chinh
ciia
nhieu nhdm dan tdc
phin Idn
la
liia nip
va lua
nuong. Ket qua nghien ciru, phan loai cac gidng
liia
dja phuong d cac dan tdc thilu sd
mien mil phia Bac Viet Nam (Quynh, 2004) theo chi tieu phan nhdm indica-japonica va
nep-te cho thay:
liia
japonica-indica d dan tdc Mudng la
95,7%-4,3%,
d dan tdc Dao la:
87,3%-12,7%,
dan tdc Tay la: 76,6 %-23,4%, dan tdc
Niing

la: 75,0%-25,0% va dan tdc
Thai la 69,2%-30,8%. Ket qua nghien
ciiu
phan loai cho thay: tat ca cac nhdm dan tdc d
khu vuc mien mil phia Bac trdng liia japonica
chii
yeu la
liia
nuong va
liia
nep nhieu
hon
Ilia
indica.
Ket qua thu thap cac gidng
liia
can tir 5 huyen
ciia
tinh Dae Lac trudc day:
Krdng Ana, Dak Mil, Krdng Buk, Eakar, Krdng Nd, P. V. Hien (2002) cho biet ngudn
tai nguyen
liia
dac san khu vuc Tay Nguyen, ma chu yeu la
liia
can cdn tuong ddi
phong phii, tuy vay noi day dang bao ddng ve
sir
suy giam ngudn gen nay.
Ngudi Kinh thugc nhdm cu dan ngudi Viet cd thudng tni d cac ddng bang chau
thd cac eon sdng

Idn
vdi phuong thiic canh tac
chii
yeu la
liia
nude.
Ngudn gen cay
liia
d 2 khu vuc ddng bang sdng Hdng va DBSCL phat trien da dang va ddng gdp
Idn
cho
san xuat
liia
cua Viet Nam. Chau thd sdng Cuu Long vdi ngudn tai nguyen di truyen lua
thom cd truyen, mang cac dac diem ndng hgc
ciia
nhdm gidng Khme-Viet, thom, ngon,
dang hat thon dai, thugc nhdm indica. Ngudn gen nep d chau thd sdng Cuu Long it da
dang hon so vdi Bac Viet Nam, hat thom nhung it dinh hon, the hien cac dac diem cua
lua indica (NghTa, Buu, Trinh & Thao,
2001).
2.3.4 Tinh khang
ciia
giong dac san vdi sau benh
2.3.4.1
Khd ndng
khdng binh bgc
Id
(Xanthomonas
oryiae)

Nghien
ciiu
da dang ngudn gen di truyen cay
liia
d DBSCL, Buu & Lang (2002)
cho biet 130 gidng
liia miia
dugc thanh lge vdi ndi vi khuan gay benh bac la cd: Nep
Than,
Liin
Vang la nhd, Chet Cut, Bdng Sen la 4 gidng khang benh bac la cung cap
ngudn gen lan
xa-13.
Nip
Mau Luon cung cap ngudn gen khang trdi Xa-7. Gidng Tram
Bdng, Nang Tay
Diim
cung dp ngudn gen khang trdi
Xa-14.
Dilu dang
chii
y la ngudn
gen khang benh bac la d DBSCL hay Ddng
bing
sdng Hdng
phin Idn
la cac gidng
liia
nip
va lua thom (NghTa & CS. 2007).

2.3.4.2 Kha ndng khang binh dgo dn (Pyricularia oryzae)
Danh gia kha nang chdng chju benh dao dn cua 48 mau gidng
liia
nep va lua
thom miln
BIC
Viet Nam (NghTa & CS., 2004) cho bilt:
Liia
thom cd kha nang khang
benh dao dn cao vdi 95,2% khang va 4,7% nhiem.
Phin Idn liia nip
bj nhiem dao dn
tuong ddi cao (66,6%), chi ed 25,9% khang cao va 7,4% khang trung binh.
Nghien
ciiu
danh gia kilu hinh kha nang chdng chju benh dao dn ndi PO-6 do 2
gen Pi-5(t) va Pi-3(t) dilu khiln
(IRRI) ciia
100 gidng
liia miia
dja phuong ma
chii
ylu
cua DBSCL (NghTa, 2005) cho
thiy:
Cac giong lua dac san d DBSCL bilu hien tinh
khang d mirc cao ddi vdi ndi
nim
dao dn P06-6 (57%). Trong sd nay cd nhilu gidng
dac san ndi tieng cua DBSCL nhu Nang Thom Chg Dao, Nang Huong, Nang Thom,

Nang Thom Ddc,
Nip
Mo Ddc va
Nip
Mil U. Tuy vay theo
kit
qua phan tich thi
mlu
gidng Nanh Chon
(1736)
bj nhilm benh.
2.3.4.3
Kha nang chdng chiu binh Vdng
Liin
(VL),
Liin Xo&n Id
(LXL)
Theo ket qua danh gia benh VL & LXL tren 346 gidng
liia miia
trong dilu
kien
djch benh VL-LXL nam 2007 cua Vien KHKT NN MN cho
thiy:
Mdt sd gidng hoan toan khdng nhilm benh chiem ti le
13%
trong tap doan giong
nghien
ciiu
nhu:
Liia

Tieu, Chet Sdm, Nang Thom, Ddc Dd, Gan Da Sdm, Nang Phet
Keo Lai, Nang Huong ddng 9, ddng
12,
ddng
18,
Nang Huong chg Dao, Nang Lilu,
Huyet Rdng, Nang Keo, Nang Sau, Dd Muong Man va Chau Hang Vd Trang. Cac
gidng nhiem benh vang
liin
thap (< 5%) nhu: Nang Co, Tieu Phung, Nang Mum, Chet
Xanh 2, Nang Huong ddng 16, Nhd Dd, Chau Hang Vd Dd.
Nam 2008, djch VL-LXL tiep tuc hai tren
liia
miia,
ket qua danh gia tren 100
gidng
Ilia
mua cua Vien KHKT NN MN ciing cho thay cd mdt sd gidng rat it bj hai
nhu: nhirng gidng lua phuc hdi sau khi bi nhiem benh VL, trdng tiep tuc vu sau dugc
ghi nhan khang benh tdt (Chau Hang Vd Trang). Cac gidng
liia
ed ti le nhiem benh VL-
LXL it <10% la: Mdt bui dd, Chau Hang Vd Trang, Chet
sdm.
Hue ky, Nang Huong
ddng 7 va Tau Ldn, Viing Hai.
Liia
nep: nep An Do, nep Ao Gia, nep Ba Bdng, nep
Cam, nep Can
Dude,

nep Ca Rang, nep Dong, nep Huong, nep IR65, nep Lai Gudt, nep
Lira, nep mien Tay, nep Rudi Xanh, nep Sdng Be va nep Than.
2.3.4.4 Khd nang khdng ray nau (Nilaparvata lugens)
Danh gia kha nang khang ray nau
ciia
77 gidng
liia
dac san mien Bac Viet Nam
tai Vien KHKT NN VN
(21
gidng thom, 27 gidng
nip,
29 gidng
liia
nuong) ket qua cho
thay
100%
sd gidng
ciia
ca
3
nhdm deu bj nhiem ray.
Theo ket qua thanh
Igc
gidng khang ray nau trong nha ludi ddi vdi 200 gidng dja
phuong cua Vien KHKT NN MN nam
1991
cho
thiy
khdng cd gidng khang ray, nhumg

cd mdt sd gidng chdng chju ray trung binh (cap 5) nhu: Bang Nggc, Trang Hda Binh,
Mien Den, Mien Tring, Tau Ldn, Chan Huong (Thjnh, Chien & CS., 1991).
Nghien cim kha nang khang
riy
nau cua 273 mau gidng
liia
dja phuong tai Vien
Liia
DBSCL cung cho
thiy
chua cd gidng
liia
dja phuong nao ghi nhan cd gen khang
ray nau vdi quan the lan tap giira biotype va ngoai trir 3 quan the
liia
hoang dai (Buu &
Lang, 2002).
2.3.5 Danh gia pham chat lua dac san
2.3.5.1
Hinh
dgng hgt gao
Hau het cac gidng
liia
dac san cd truyen mien Bac Viet Nam ed chilu dai hat
thugc loai dai chilm khoang 80% va ty le D/R tap trung d mirc trung binh tir 2,1-3
chiem 67%, d
miic
thon dai (>3) chilm 20%. Cac gidng
liia
thom cd truyin d miln

BIC
va cac gidng
liia
nuong d miln mii, nhat la cac gidng cd hat thon dai nhu Tam Xoan
Ninh Binh, Tam Cao Nam Djnh, Tam Ap Be,
Pllu
Sang,
Pllu
La va
Pllu
Hiing la cac
gidng khdng bac bung chilm
gin
80%.
Dang hat gao ciia cac gidng dac san cd truyin d miln Nam
thi
hien it da dang
hon so vdi miln
BIC
va phan ldn cd chilu dai thude dang hat dai hoac trung binh (6-
7mm),
cd ty le D/R = 2-3 hoac > 3 (NghTa, Buu, Trinh, Thao, 2001). Cac gidng lua
thom cd truyen d mien Nam nhu: Nang Thom Chg Dao, Nang Huong va Nhd Dd cd hat
gao dai, com thom mem nhung hat bj bac
giiia
nhilu. Gao bac giira ma ngudi dan dja
phuong ggi la "hat luu" van dugc ua chudng, nhilu ngudi cho
ring
gao thom bac giiia
cang nhieu thi cang cd

miii
thom.
Cac gidng
liia
thom cai tien hoac nhap ndi dugc san
xult
nhilu d DBSCL nhu
Jasmine 85, KDM 105, OM 3536, VD20, ST3,
STl phin
ldn thugc hat dai, gao trong.
2.3.5.2 Pham chat
carm
* Ham luong amylose
Ham lugng amylose la yeu td quyet djnh tinh com deo, com mem hay com ciing.
Gao cd ham lugng amylose cang cao thi com cang nd nhung dl bj khd va cimg com khi
ngudi. Theo tieu chuan amylose Juliano va Villareal (1993) da xep thanh 5 nhdm:
Nhdm ggo-cam Hdm luang amylose (%)
Nip
0-5
Rat thap, com rat deo
5,1-12
Thap,
com deo 12,1-20
Trung binh, com mem
20,1-25
Cao,
com cirng > 25
Theo
Biii
Huy Dap (1980), cac gidng liia dac san cd truyen ndi tieng d mien Bac,

nhu cac gidng
liia
Tam, thudng cd ham lugng amylose khoang 20% (trung binh). Cac
gidng lua nuong d viing mien nui thudng cd ham lugng amylose khoang
15%
(thap)
nen com deo ngay ca sau khi nau nhieu gid. Le Doan Dien (2002) cho rang: cac gidng
Ilia
dac san cd truyen
ciia
Viet Nam thudmg cd ham lugng amylose trung binh hoac cao.
Dae biet cd
19
gidng
liia
Tam trong sd 108 gidng nghien cim cd ham lugng amylose
trung binh. Day la uu the
ciia
gao Tam trong tap doan cd truyen mien Bac Viet Nam.
Kit
qua nghien cim Vien
Liia
DBSCL (2005) cho
thiy
cac gidng lua cd truyen d
mien Nam ed cac ham lugng amylose
rit
khac nhau: Nang Thom Chg Dao (22.07%),
Nhd Thom (22,5%), Nang Huong (23%) va
thip

nhu Thom
Miia
(5,6%) va loai cimg
com nhu Nang Phat Don (28,6%), Thom Sdm
(31,26%)
va Nanh Chdn (35,47%).
Tnrdmg hgp dang
chii
y la cac mau
ciia
ciing mdt gidng lai cd ham lugng
amylose khac nhau. Cac sd lieu phan tich ham lugng amylose trong tap doan gidng lua
miia
d DBSCL,
kit
qua gidng
Nang.
Huong (tir •20,86%-30,95%), Nhd Thom
(22,3%-
32,08%),
Nang Thom Chg Dao
(18,86%-26,64%)
va Nanh Chdn
(22,71%-34,92%).
Vi
vay viec chgn
lira
gidng cd ham lugng amylose
thip
dn xem lai cac mau gidng khac dk

cd vat lieu lai tao mong mudn.
* Nhiet do hoa
h6
(GT)
Nhiet do hda hd la nhiet do can thilt dk gao biln thanh com va khdng hoan
nguyen. Nhiet do hda hd biln thien tir 55
V-79°C
va phan 3 mire theo
IRRI,
1996:
- Nhiet do hda hd
thip:
55-69
°C
- Nhiet do hda hd trung binh: 70-74
°C
- Nhiet do hda hd cao:
75-79°C
Nhiet do hda hd dugc danh gia thdng qua chi tieu do phan hiiy kiem cua hat gao
(ngam 23 gid trong dung djch KOH 1,7%) va theo thang dilm IRRI, 1996. Nhu vay gao
cd do phan huy kiem thap se cd nhiet do hda hd cao va ngugc lai gao cd do phan
hiiy
trong kiem cao se cd nhiet do hda hd thap. Gao cd do phan
hiiy
kiem trung binh se co
nhiet do hda hd trung binh. Thdng thudng gao cd nhiet do hda hd cao thi com nau lau
chin, khd com so vdi gao cd do hda hd trung binh va thap. Tuy vay cd vai trudng hgp
ngoai le, tuy cd do hda kiem cao nhumg com van bj cimg nhat la sau khi de ngudi.
Danh gia do phan
hiiy

kiem eua cac gidng lua dja phuong mien Bac Viet Nam
(Quynh, 2004) cho thay
liia
nep va
liia
te tap trung d hai
miie
trung binh va cao
(liia
nip:
49,6-42,8%;
liia
te:
43,9-31,7%).
Tuu trung lai la hau het cac gidng
liia
nep va
phin
ldn
liia
te dja phuong mien Bac Viet Nam cd nhiet do hda hd thap va trung binh.
Theo
kit
qua danh gia, phan tich do hda kiem
ciia
Vien Lua DBSCL (Lang,
2002) ddi vdi mdt sd gidng dae san cho thay phan ldn cac gidng
liia
cd do hda kiem
thip

(dp 2-3). Chi cd mdt mdt sd
mlu
gidng Tau Huong, Tieu Chet, Bdng Tay, Nhd
Thom, Mdng Chim, Nang Huong, Nanh Chdn va Thom Sdm cd do hda kiem cao
(nhiet do hda hd thap).
*
D9 bin thi
Gel (Gel consistency)
Do
bin thi
Gel dugc xem xet
dlu
tien vao nam 1972 (Cagampang & CS.,
1973) va dugc tdng hgp mdt each cd he thdng bdi Perez, 1979. Do ben the Gel la chi
tieu dl bilt do nhot cua
thi
Gel hat gao. Do
bin
the Gel dugc xac djnh bdi chieu dai
thi
Gel theo thang dilm chuin qudc tl (Tang et al., 1991): 80-100 mm (dp 1. dinh com);
61-80 mm (dp 3,
mim
com); 41-60 mm (dp 5, trung binh); 36-40 mm (cap 7, cimg);
< 35 mm (cap 9. rat cimg).
Theo
kit
qua dl tai KHCN
08-01.
1996-2000 (bao cao cua Vien Lua DBSCL),

cac gidng lua thom KDM, Nang Huong 3, Nang Quat, Nang Thom Thanh Tra va Nhd
Thom cd dg
bin
Gel tuong img la: 66, 68, 62, 62, va 64. Cac gidng nep nhu:
nip
Dai
10
Loan, nep Ba Gia, nep Keo, nep Mau Luon, va
nip
Sap cd do
bin
Gel tuong img la:
100,
66, 100, 100, va
100.
Nhu vay do ben
thi
Gel cua cac gidng
liia
thom, liia
nip thi
hien rat khac nhau theo thang diem danh gia.
Phin
ldn cac gidng
liia nip
cd chilu dai
the Gel d mirc 100 mm (cap 1), d dang
mim
hon gidng
liia

thom. Nhin chung cac gidng
Ilia dac san cd truyen cd do ben
thi
Gel dai hon,
tiic
la com
mim,
deo hon so vdi da sd
cac gidng cai tiln. Trong nhirng gidng
liia
cd ham lugng amylose nhu nhau thi gidng
nao cd do ben the Gel mem hon thi gidng dd se dugc ua chudng nhilu hon (Khush,
1979;
Juliano, 1990).
* Ham luong protein
Protein tuy chiem ty le nhd (khoang 8%), nhumg la thanh
phin
dinh dudng vd
ciing quan trgng
ciia
hat gao. Protein gao cd gia trj dinh dudmg cao hon nhilu protein
cac loai
ngii
cdc khac, do protein
ciia
hat gao giau cac amino acid khdng thay
thi
nhu:
Lysine, Threonine, Methionine va ca Cystine. Nlu gia trj dinh duong
ciia

trirng va sira
la
100
thi gia trj dinh dudmg
ciia
gao la 83-86,
ciia
bdt my la 62-77, cua ngd la 52-58 va
ke la 57. He sd hiru hieu
ciia
protein gao ciing cao hon
hIn
so vdi hat cdc luomg thuc
khac (Bill Huy Dap, 1980; Juliano, 1985). Theo Hirokadzu Taira (1985) thi ham lugng
protein trong hat gao eua cac gidng
liia
ngan ngay va
liia
thap cay nhin chung cao hon
cac gidng
liia
dai ngay va gidng liia cao cay. Gomez & De Datta (1975) cho biet cd
sir
tuong quan bac 2 giira nang suat va ham lugng protein tren ciing mdt gidng. Ca 2 dac
tinh nay cimg tang thdng qua tac ddng eua yeu td mdi trudng, bien phap canh tac va
tang len dinh diem, sau dd neu tang ham lugng protein thi se lam giam nang suat. Vi
vay can
chii
y dieu chinh che do trdng trgt sao cho tang ham lugng protein va kem theo
sir

hy sinh nang suat den diem hgp ly nhat djnh.
Ham lugng protein cua gao gidng
liia
Viet Nam nhin chung thap hon muc trung
binh cua nhieu nude. Trong cac gidng
liia
Viet Nam thi nhdm Tam Thom chiia it
protein nhat (bien ddng = 5,35-7,7%; trung binh = 6,52%) cdn nhdm
liia
nep thi chira
nhieu protein hom ca (bien ddng = 7,25-8,56%; trung binh = 7,94%)
(Biii
Huy Dap,
1980).
Danh gia ham lugng protein cua 200 gidng
liia miia
ma
chii
yeu la cac gidng dac
san cd truyen
ciia
DBSCL, sd lieu cua Vien Lua DBSCL da cho biet ty le phan bd cac
gidng nhu sau: nhdm 1 (1,0%; protein >10%); nhdm 2
(7,5%;
protein > 9%); nhdm 3
(19,0%,
protein > 8%); nhdm 4 (29,5 %, protein > 7%), nhdm 5
(31,5%,
protein > 6%),
nhdm 6: (

11,5%,
protein > 5%). Ca 2 gidng cd protein cao
ciia
nhdm
1
la hai gidng
liia
ndi tilng
ciia
Nam Bd la Nang Huong va Nang Thom Chg Dao.
* Mui thom
Cho
din
nay
phin
Idm cac nghien ciru tap trung vao
miii
thom cua com. Trong
cac nghien
ciiu
sdm
nhit,
cac
chit
nhu hydrogen
sulfic,
ammonia, carbon dioxide &
aldehyde dugc xac djnh la thanh
phin
dl bay hoi trong gao da nau chin (Hirokadzu

Taira, 1995). Cac nghien cim tilp theo da xac djnh khoang
150
loai chat dl bay hoi va
chiing bao gdm nhilu hgp
chit
carbonyl nhu pentanol va herxanol (Legendre et al.,
1978;
Kato et al.,
1983).
Hien nay cd hai quan diem ve thanh phan chat thom cua lua
11
gao.
Quan diem
thii
nhat cho rang chat thom dugc tao ra tir cac hgp chat aldehyde
(CHO) va ceton (C
=
O) va cac hgp
chit
luu huynh (Tsuzuki, 1997). Quan dilm thir
hai cho rang chat thom
ciia liia
gao do vdng
pyryl
kilm soat tinh thom
ciia
chat 2-
acetyl-1-
pyroline (Buttery
8L

CS., 1983a). Lorieux, Petrov va CS. (1996) da phan tich
mau gao cua 2 gidng
liia
Azucena (thom) va gidng IR 64 (khdng thom), phan tich djnh
lugng cua
15
hgp
chit
chinh lien quan
din
2 gidng tren. Khdng tim
thiy chit
2-acetyl-
1 -
pyroline d IR 64, trong khi d gidng
liia
thom Azucena
chit
nay cd ham lugng cao.
Trong sd 89 hgp chat phan tich, xu ly thdng ke cho
thiy
cac
chit
sau cd
sir
khac biet
giira gidng
liia
thom va khdng thom: pentanol, 2-
acetyl-1-

pyroline, benzaldehyde;
octanol, pentadecan -2-one, 6, 10,
14-imethylpentadecan
-2-one & hexanol. Tsuzuki &
CS.
(1977) khang djnh
liia
thom cd chiia mdt sd lugng Idn nhiing hgp chat carbonyl so
vdi gidng
liia
thudng va day la su khac biet giira
liia
thom va
liia
thudng. Buttery & CS.
(1983) da nghien cuu 7 gidng
liia
thom. Trong sd cac thanh phan xac djnh
ban^
phuong
phap sac ky khi, hgp chat
2-acetyl-l-pyroline
da tim thay va cd
miii
thom tuong tu nhu
mill thom cua com. Hussain
&.
CS. (1987) da so sanh
miii
thom cua ciia

liia
thom
(Basmati) va
liia
khdng thom, xac djnh hgp chat thom tai viing dinh cua cac bieu dd sac
ky, noi the hien cd nhieu pentadencan-2-one, hexanol va
2-pentylfiirane
d lua Basmati.
Chat
2-acetyl-l-pyroline
da khdng tim thay. Nhung hau het cac nghien
ciiu
sau nay deu
chi rd vai trd quan trgng ciia hgp chat thom nay va xac djnh ham lugng cua nd trong
gao xat thay ddi tir 0,006 den 0,09 ppm. Thi nghiem
ciia
Trung tam Nghien cim Ndng
nghiep viing cua bd Ndng nghiep Hoa Ky va IRRI (1982) cung cho thay ham lugng
chit
thom
2-acetyl-l-pyroline
eua Khao Dawk Mali 105 la 0,07 ppm, Basmati 370 la
0,06 ppm va gidng ddi chiing Calrose la 0,006 ppm.
Phan tich
miii
thom hien nay dugc ap dung theo nhieu phuong phap: djnh tinh
bing
phuong phap cam quan; djnh lugng phan tich bang may sac ky khi (gas
chromatography) vdi mdt bd "detector" cd tinh chgn lge (Juliano, 1993). Ngay nay
cdng nghe sinh hgc da ap dung dl xac djnh gen kiem soat tinh thom qua marker phan

tu, phd biln dl xac djnh gen thom la phuong phap micro satellite marker.
Theo
kit
qua danh gia cua Vien Lua DBSCL, Vien KHKT NN MN cac gidng
Ilia thom d Nam Bd thdng thudng dat dp 1 (thom nhe), sd lieu danh gia cam quan
tuong ddi biln ddng. Cd nhilu trudng hgp vdi cimg mdt gidng nhung cho ket qua khac
nhau. Dilu dd cd
thi
ly giai do tinh
chit ciia
gidng khdng ddng nhat, hoac ngudn danh
gia d nhilu viing sinh thai khac nhau, hoac
miic
do nhay cam cua ngudi danh gia
miii
thom. Vi vay danh gia
miii
thom ddi hdi phai ap dung nhieu phuong phap va phai tuan
thu chat che cac yeu du ky thuat khi danh gia
miii
thom ciia
liia
gao.
2.4 Anh
hudng
yen to moi trucmg den nang suat,
phSm chSt liia
gao dac san
2.4.1 Anh
htfong

ciia dieu kien thdi tiet
Nghien cim anh hudng cua nhiet do trong thdi ky chin den ham lugng tinh bdt da
dugc Asaoka. Resurreccion & CS, 1995 tiln hanh tren gidng
liia nip
va lua te. Ket qua
nghien cim cho
thiy
cac cay gieo trdng trong dilu kien
25°C
vao sudt thdi ky sau trd cd
12
tinh bdt dang mach thing (amylose) cao hon so vdi nhumg cay trdng d nhiet do
30°C
vao ciing thdi ky. Ty sd trgng lugng giira amylopectin chudi
ngin
va amylopectin chudi
dai cua tinh bdt tir nhiimg cay
liia nip
cung nhu
liia
te phat triln trong dilu kien nhiet do
25 C la cao hom so vdi nhumg cay phat triln trong dilu kien nhiet do
30°C.
Nhiet do
trong giai doan hat chin anh hudng
din
ham lugng amylose (Stansel, 1985). Ham lugng
amylose thudmg giam khi nhiet do trung binh tang. Tuy vay mirc do mirc do phan img
cdn
tiiy

thugc theo nhdm phu japonica hay indica va phu thugc vao
miic
do di truyin
cua gidng (Resuneccion & CS., 1977). Resurreccion & CS., 1977 cdn cho bilt ham
lugng amylose cua gidng Fujisaka 5 (japonica) giam khi nhiet do tang, trong khi gidng
IR 20 (indica) cd ham lugng amylose tang khi nhiet do dudi
29°C,
nhung lai giam khi
nhiet do tang tren 29 C.
Sir
bien ddng
ciia
ham lugng amylose giira cac cay it hon 2%)
nhung
sir
khac nhau giira cac bdng trong ciing bui
liia
lai cao 3-7%. Vi vay dn cd
sir
hon hgp
mlu
deu khi phan tich ham lugng amylose. Nhiet do cao khi
liia
trd
din
vao
chac,
thieu
nude
trong giai doan

bit dlu
phan hda ddng
din
tro lam tang ty le gao bac
bung cua cac gidng
liia
(Nakata va Jackson,
1973;
Somrith, 1974). Theo Nagato and et
al.
(1964) nhiet do tang lam tang ty le bac bung, nhiet do ban dem
thip
d giai doan 15
ngay sau khi trd lam giam ty le bac lung. Ty le gao nguyen la tinh trang di truyin bj anh
hudng manh bdi dieu kien ngoai canh dac biet la nhiet do & Im do trong sudt thdi gian
hat chin, keo dai cho
din
khi thu hoach (Juliano, 1990; Buu & CS., 1996). Ty le gao
nguyen thay ddi
tiiy
theo ban chat di truyen
ciia
gidng va phu thugc vao nhieu dieu kien
mdi trudng nhu nhiet do, am do khi
liia
chin va dieu kien phoi
sly
sau khi thu hoach
(Le Doan Dien,
1990).

Huysmans
(1965)
cho rang
sir
ran nirt eua hat thudng do nang
ndng, do
sir
thay ddi nhanh cua am do khdng khi, do
sir
bat thuan cua mdi trudng trong
thdi gian chin cua bdng hat va do thu hoach tre trong vu ndng lam hat cd do am thap.
Thdi tiet trong cac vu
liia
anh hudmg kha rd den nang suat va pham chat
ciia
cac gidng
Ilia,
nhat la cac gidng dac san. Theo Gomez & De Datta (1975), De Datta
(1981)
ham
lugng protein
ciia
gao cd xu hudng thap khi birc xa anh sang manh xay ra d giai doan
phat trien ciia hat. Vi vay d vimg nhiet ddi ham lugng protein cua hat thudng thap trong
miia
khd va cao
hofi
trong
miia
mua. Nhiet do trong thdi gian chin ciing anh hudng den

ham lugng protein trong hat, nhumg thay ddi
tiiy
theo nhdm gidng. Nhdm japonica tang
ham lugng protein khi nhiet do trung binh tang, cdn nhdm indica lai khdng cd
sir
thay
ddi.
Pham chat gao nep ciing nhu gao te phu thude vao
miia
vu gieo trdng. Gao vu
Miia
thudmg ngon com hom so vdi gao vu Chiem
(Biii
Huy Dap, 1980). Tai DBSCL cac
gidng gieo trdng trong vu Ddng Xuan thudng cd do bac bung it hom so vdi vu He Thu.
Do chat lugng ciia cac gidng
liia
thom ngan ngay d DBSCL trong vu He Thu thap nen
nhieu dja phuong khuyen cao nen trdng d vu
Miia
hoac vu Ddng Xuan.
2.4.2 Anh huong cua dieu kien dat dai
Chat lugng cua cac gidng
liia
dac san phu thugc rat Idm vao dieu kien ngoai canh.
Cac gidng
liia
thom cd truyen ndi tieng cua Viet Nam
giii
dugc chat lugng va

miii
thom
dac tnmg vdn cd khi dugc gieo trdng tai viing ma nd tdn tai tir lau. Vi du Nang Thom
13
Chg Dao, Tam Thom Hai Hau. Nep
Tii
Le giir dugc
chit
lugng va
miii
thom khi dugc
trdng d chinh xuat xir tai My Le.
Cin
Dude (Long An), Hai Hau (Nam Djnh),
Tii
Le
(Yen Bai). Dieu nay cd the ly giai la
chit
lugng
ciia
cac gidng
liia
dac san la
kit
qua tac
ddng
ciia
gen va mdi trudng trong dd ylu td mdi trudng
dit,
nude

anh hudng
rit
rd
(NghTa & CS., 2007). Tham chi. tai xa My Le, lua Nang Thdm Chg Dao cd
miii
thom
dac trung neu dugc trdng d Ip 2, Ip
11,
trong khi trdng d Ip 7 gidng da giam
miii
thom
nhilu (Thjnh, 2004).
Gao
ciia
cac gidng
liia
dugc trdng tren
dit
can ed ham lugng protein cao hon
gao cua cac gidng lua trdng d vimg
dit thip
ngap lut (Hirokadzu Taira, 1995). Gao cua
cac gidng
liia
nuong d Viet Nam ngon va deo hon so vdi gao rudng
(Biii Hu>
Dap,
1980).
Dat trung thudng thieu kali va di ddi vdi ngd ddc
sit.

Hien tugng nay thudng
thay tren dat dd va dat phen. Thilu kali kem theo cac ddm nau do benh
Helminthosporium tren la, la trieu chimg thdng thudng
ciia
benh
"Akiochi"
xay ra tren
dat cat d Nhat Ban va Trieu Tien. Tren
dit
kem thoat
nude
cung thilu kali.
Phim chit
gao
ciia
cac gidng tren nhirng loai
dit
nay dlu bj anh hudng dang kl
(Imaseki
&
Hamakawa, 1936).
Nghien
ciim
anh hudng
ciia
mdi trudng
din phim chit
hat cua cac gidng
liia
d

DBSCL,
kit
qua dl tai KHCN 08-01 (1996-2000), cho
thiy:
amylose cua gao viing
dit
phen cd xu hudng cao hon va 4 tinh trang pham chat gao kem dn djnh giiira 2 mdi
trudng dat thuan
Igi
va khdng thuan
Igi
(dat phen) la: amylose, ty le gao nguyen. do bac
bung va do ben the Gel.
2.4.3 Anh
huong
cua bien phap ky thuat
2.4.3.1 Phan dam (N) vdi nang sudt
va
pham chdt
liia
Tren dat
phii
sa dugc bdi hang nam
ciia
DBSCL dam van la yeu td han che den
nang suat
liia.
Ndi chung, bdn dam cho
liia
thi cd hieu qua, nhung hieu qua tdi da d

miic
bdn 90N so vdi bdn it hoac bdn nhieu dam hon (Pham Sy Tan, 1994). Ddi vol cay
liia
nude, dac biet d viing khi hau nhiet ddi, viec bdn phan dam dugc ket hgp giira bdn
Idt
va bdn thiic voi
sir
chia nhd ra bdn thanh nhieu lan se gdp phan nang cao hieu qua
ciia
bdn phan dam, giam dugc
sir
that thoat (Mai thj Bich Hdng, 1995). Nghien cim anh
hudmg
ciia
phan dam den pham chat
liia
gao, Suwanarith and et al.
(1997)
cho biet
miii
thom, do dinh, do mem com va mau sang
ciia
gao Khao Dawk Mali bj anh hudmg bdi
phan dam. Bdn phan dam tre d thdi ky trd bdng cd the cai thien pham chat dinh duong
cung nhu ty le xay xat. Tuy nhien, khi diing phan dam nen chia ra bdn nhieu lan de cd
pham chat gao tdt hom (Perez and et al 1996). Bdn phan dam d giai doan trd bdng lam
tang ham lugng protein 10-30% trong gao lut, nang suat protein tren don \i dien tich
tang gan 2 lan so xin ddi chiing do ket hgp lam tang ham lugng protein trong hat va
tang nang suat hat. Hieu qua cua phan dam ddi vdi ham lugng protein trong gao rd nhat
la bdn dam d giai doan cang gan thdi ky trd deu cua cay

liia
(Taira and et al 1970).
Mdt sd nghien cim khac cho thay: ham lugng protein trong gao cd su tuong quan thuan
vdi ham lugng dam cua 3 la tren ciing d giai doan trd bdng
(Hongjo,
1971) va vdi ham
lugng dam cua be la va than ra d giai doan trd bdng (Taira and et al., 1974). Bdn phan
14
dam d giai doan phan hda ddng cd the khdng tao nen
sir
thay doi ham lugng protein va
lam giam
miii
vj cua com (Singh, 1997). Lilu lugng, thdi gian bdn dam va thdi gian
tieu nude tren rudng cung anh hudng
din
ty le gao nguyen. Nlu bdn dam vdi lilu lugng
cao se lam cay dd va ty le gao nguyen bj giam (Hou, 1990).
2.4.3.2 Phdn ldn (P)
v&i
ndng sudt
vdphdm
chdt
Ida
ggo
Ddi vdi cay lua, khi
dit
thilu P,
sir hip
thu N & K bj giam cd y nghTa va nang

suat bj giam so vdi trudng hgp bj thilu K hoac N, ddng thdi
liia
cd ty le hat xanh va
khuylt tat cao.
Kit
qua nghien curu
ciia
Fujiwara & Ohira
(1959)
cho
thiy:
khi cung dp
mdt lugng Idm P, ham lugng P
ciia
hat
liia
se tang. Nhumg khi cung dp mdt lugng 1dm
Fe va Mn ciing vdi P thi ham lugng P giam. Mdt sd mudi cd tac ddng tang cudng
sir
hip
thu P cua cay lua, ngoai trir cac cation,
thii
tu tac ddng tuong ho
ciia
mudi la: SO4,
CI,
NO3.
Mitsui va Tensho (1957) da kilm tra
sir
tac ddng tuong ho cua mudi

(CaCb
va
KCl) ddi vdi
sir hip
thu phosphate cua
liia,
su dung
^^
P, thi nghiem cho
thiy
su
hip
thu
P dugc tang cudng do cac mudi ciing hda tan. Bdn phan P lam tang cudng ham lugng
protein trong gao, tuy nhien bdn nhieu se lam
phim chit
gao giam.
Mai Van Quyln
(1996)
cho bilt nlu khdng bdn dam nhung bdn 40kg
P205/ha,
nang
suit liia
da tang \6%. Cd phdi hgp vdi N va P nang
suit
tang ddng biln vdi viec
tang lugng lan bdn vao. Tren
dit
phen nang hoac trung binh, su dung phan lan Van
Dien, hoac lan TP + SP va SP-M cd hieu qua cao hon so vdi diing DAP. Doi vdi loai

dat nay, bdn lan ngoai tac dung cung cap P, cdn lam giam ddc hai Fe, Al di ddng ddi
vdi cay
liia
(Mai Van Quyln, 1996; Mai Thanh Phung & Husson, 1994).
2.4.3.3 Phdn kali
(K) v&i
ndng sudt
vd
phdm chdt
Ida
Nghien cuu anh hudmg eua kali ddi vdi cay liia (Fujiwara and Lida, 1956) cho
thay: khi thieu kali, cudng do hd hap tang, ham lugng acid hiru co 3 carbon tang len (la
ket qua cua
sir
thieu oxy), cdn cac acid amine thi bj giam, ngoai trir glutamine. Trong
qua trinh phat trien
ciia
cay liia, giai doan dau hieu
lire ciia
K cao, sau dd giam xudng
va d giai doan cudi lai tang cao. Do vay, viec bdn K day
dii
cho cay
liia,
nhat la bdn bd
sung K vao
liic
trd bdng, giai doan cd tinh quyet djnh ddi vdi nang suat. Khoang 20% K
do cay hiit dugc van chuyen ve bdng, sd cdn lai duy tri d cac bd phan khac. Bdn K lam
cho than cay

liia
ciing hon, khdng dd nga. Mat khac K giup cho cay lua tang khdi lugng
hat, giam ty le
lep,
tang tich luy tinh bdt va chat khd trong hat. Phan K anh hudng tdt
den pham chat xay xat va huong vj cua com gao. Bdn nhieu K cho gidng Khao Dawk
Mali
105,
khdng nhirng se cd nang suat cao, ma mau gao se sang hom va
miii
se tang,
nhung do mem com se bj giam (Suwanarith & CS., 1997). Theo Mai Van Quyen & Dao
The Tuan
(1969),
thieu K khdng chi anh hudng ddi vdi hinh thai
ciia
cay
liia
nhu chieu
cao,
sd nhanh, mau sac ma cdn anh hudng den cudng do hd hap va tdng hgp, tich liiy
cac chat hiru co cua cay lua nhu dam, dudng.
6
cac tinh phi Nam, nhieu ket qua nghien
cim cho thay hieu
lire ciia
K
cCing
rat bien ddng tren nhieu loai dat khac nhau. Cdng
Doan Sat (1994) cho biet K khdng chi anh hudng den nang suat ma cdn anh hudng den

chat lugng cay trdng. Hieu
lire
cua K phu thude vao loai dat, thdi vu gieo trdng. Cimg
vdi dam, K la yeu td hang dau lam tang nang
suit
va
phim chit
cac loai cay trdng tren
15
dat xam. Tren
dit phii
sa DBSCL, K chi cd hieu
lire
trong vu Ddng-Xuan khi nang
suit
dat 6 t/ha trd len. Tren
dit phii
sa, K cd hieu
lire thip
ddi vdi nang
suit
nhung cd anh
hudmg rd ddi vdi
phim chit
gao, bdn
30-60kg K2O
kg/ ha thi lugng gao nguyen tang
11-13%
so vdi ddi chimg khdng bdn K (Cdng Doan
Sit,

1994).
2.4.3.4 Bdn phoi hpp NPK vd phdn hieu ca
Tren dat
phii
sa giau kali dugc bdi hang nam, bdn N don ddc (lien tuc trong
15
vu) nang
suit
chi tang 16%, cdn nlu bdn ca 3 nguyen td NPK nang
suit
tang 67,4% so
vdi ddi chimg khdng bdn phan trong
15
vu (Pham Sy Tan, Mai Van Quyln, 1996). AH
and et al.
(1992)
da tiln hanh thi nghiem vl each bdn vdi P va K dugc bdn
Idt.
N dugc
bdn theo 2
each:
bdn 2 lan (bdn
Idt,
30 ngay sau khi gieo) va 3
lln
(bdn
Idt,
30 ngay va
60 ngay sau gieo). Ket qua cho
thiy

khdng cd
sir
khac biet vl nhiet do hda hd. Nhung 0
cdng thiic bdn N lam 3 lan cho khdi lugng 1000 hat va ty le gao nguyen cao hon so vdi
cdng thuc bdn 2 lan. Bdn N lam 2 lan lam hat gao cd do bl
thi
Gel cao
hon,"nghTa
la
com mem hon. Bdn phan hum co da cd anh hudng tich
cue din
hda, ly tinh va dac tinh
sinh vat hgc cua
dit,
lam gia tang
chit
mim
0,23-0,31%,
dam 12,8-15,3%, Ca 22,9-
28,8%,
do
din
thuy 22,4-43,4% va do thoang 12,4-20,4%. Bdn NPK
kit
hgp vdi phan
hiru
CO
lam tang nang suat liia 20,7-34,9%. Trong cac loai phu
phim,
bdn mat dira cho

hieu qua cao nhat (Tran Thi Nggc Son & CS., 1997). Nghien cim anh hudng
ciia
phan
bdn den nang suat va pham chat gao mdt sd gidng
liia
thom d Nam Bd (Dd Khac Thjnh
& CS., 2004) cho biet:
Liia
Nang Thom Chg Dao se bj giam do thom
ciia
com gao,
giam ty le xay xat va giam nang suat neu khdng bdn phan
phii
hgp. Cdng thiic bdn phan
phii
hgp cho gidng Nang Thom Chg Dao la: 60 kg N + 30-45 kg
P2O5;
hoac 50-60 kg N
+ 30-45 kg
P2O5
+ 30
K2O
+ 400 kg
hiru
co Binh Diln; hoac 50-60 kg N + 45 kg
P2O5
+ 30
K2O
+ vi lugng tdng hgp. Bdn phan hum co khoang Binh Dien hoac phan vi lugng
lam dn djnh nang suat va tang pham chat com gao cua gidng Nang Thom Chg Dao.

Bdn lugng dam cao den 90 kg N/ha cho gidng liia Nang Thom Chg Dao se lam tang
ham lugng protein trong gao, tang
miii
thom cua la, nhumg lam giam
miii
thom
ciia
com
gao.
2.4.3.5
Th&i
vu,
th&i
diim thu hoach
Somrith B.
(1996)
cho
ring miii
thom
ciia
com gao Khao Dawk Mali phu thugc
vao
miia
vu gieo trdng, loai dat, dja diem va do phi
ciia
dat. All and et al.
(1991)
cho
bilt: gidng Basmati 370 nlu dy vao ngay
1

thang 7 va Basmati 385 cay vao 16 thang 7
thi cho
chit
lugng gao tdt
nhit.
Nlu cay sdm hom
miii
thom se giam, cdn cay tre thi
ham lugng amylose tang. Komoda
(1938)
da tdng hgp ket qua ve nghien cim kha nang
thich nghi cua cac gidng
liia
khac nhau den thdi vu gieo cay mudn. Ket qua cho thay
nlu gieo dy mudn thi thdi gian sinh tnrdmg
ciia
gidng bi nit ngan lai va
chii
yeu bj nit
ngin
d giai doan tir gieo cay den phan hda ddng. Mirc do nit ngan thdi gian sinh trudng
tiiy
thugc vao gidng. Nhumg gidng chin sdm cd sd ngay nit ngan it hon so vdi gidng
chin trung binh va gidng chin mudn.
Liia
trdng d vu
Miia
sdm cd do phan huy kiem
thip
hon

(tiic
cd do hda hd cao hom) so vdi vu
Miia
mudn (Chikubu and et
al.,1965).
Nghien cim anh hudmg cua thdi vu gieo cay den nang suat chat lugng
liia
thom Nam Bd
16
(Dd
Khic
Thjnh & CS., 2004) cho
thiy:
gidng Nang Thom Chg Dao tren chan
dit
2
vu/nam
cho nang
suit
cao va
chit
lugng tdt
nhit
d thdi dilm gieo dy tir
15/7 din
30/7.
Neu trdng tren dat vu 3 chan thap, d thdi vu gieo tdi
15/9,
nang suat van dat kha cao,
nhumg mdt sd chi tieu ve pham chat bj giam.

KDM
105 cd nang suat va chat lugng tdt
neu gieo thang 7-8, dy thang 8-9, thu hoach thang 11-12. Nlu gieo 1/11- 30/12 (vu
DX) thdi gian sinh trudng nit ngan cdn
100-110
ngay, nhumg
liia
trd khdng tap trung,
chit
lugng gao giam rd ret.
Ham lugng protein bj anh hudng do thdi dilm gat
liia
khac nhau, ham lugng
protein thap khi gat qua sdm va tang len tdi dinh cao tai thdi dilm 30 ngay sau trd
(Krupp and et al., 1972). Trong vu Ddng-Xuan tai DBSCL ty le gao nguyen d 2 cdng
thiic thu hoach 20 ngay va 25 ngay sau trd dlu cao hom d 2 cdng thiic thu mudn 30 va
35 ngay sau trd
(Biii
Chi Buu va Nguyen Thj Lang, 2000). Thdi dilm thu hoach thich
hgp cho nhieu gidng
liia
dac san khi
liia
cd sd hat chin dat 90%.
2.5 Chon
loc
dong thuan va phuc trang giong dac san
Trong quan the cac gidng
cd
truyen bao gdm nhieu ca the bien dj di truyen, dd la

ngudn vat lieu tdt cung cap cho qua trinh cai thien gidng. Cac nha chgn tao gidng
df
tram nghien
ciiu
gidng lua d Pharal, Thai Lan da tach dugc 6 dang tir gidng Basmati
385 vdi cac dac diem khac nhau ve rau hat, chieu cao cay, dang hat, thdi gian chin va
mill thom. Chgn lge ddng thuan tren gidng Jeerakasala tai trudng dai hgc Karela (An
Do) ket qua xac djnh dugc 3 ddng cd dac tinh ve rau, hat khac nhau, nang suat cua ddng
thuan tdt nhat tang 50% so vdi quan the khdng chgn lge (Ramankutti and Bhaskaran,
1979).
Mdt trong nhumg chuong trinh chgn lge ddng thuan thanh cdng nhat d tieu luc
dja An Do la chgn Igc dugc ddng Basmati 370 do Late Sardar Mohammad Khan thuc
hien tir nam 1933 d
Kala
Shah
Kallu.
Gidng nay da phat trien rdng d Pakistan va An
Do,
dugc coi la gidng tdt nhat tren the gidi hien nay ve chat lugng com gao.
6
Thai Lan, Khao Dawk Mali 105 ciing la mdt thanh cdng Idn bang chgn Igc
ddng thuin. Tir 199 bdng thu thap nam 1950, qua trinh chgn lge tai tram nghien
ciiu liia
Kok Samrong. Ddng KDM 4-2-105 dugc xac djnh la ddng tdt
nhit.
Nam
1959
gidng
KDM-105
da dugc phdng thich va phat triln phd biln d Thai Lan. Nam

1997,
KDM-
105
xult
dugc 2,20 trieu
tin
trong tdng sd 5,24 trieu
tin,
chilm 42% tdng sd gao
xult
khiu
cua Thai Lan (Somrith,
1996).
Theo Khush (1979) chgn lge ddng thuin (pure line
selection) cd
miic
do cai thien gidng tdt hon, nhung chgn
Igc
quan the (mass selection)
lai dam bao tinh dn djnh
quin
the cao hom so vdi chgn lge ddng thuan.
Vien KHKT NN MN
(1994-2000)
da ap dung phuong phap chgn lge ddng thuin
thanh cdng trong cai thien cac gidng liia
miia
dac san nhu gidng Nang Huong va Nang
Thom Chg Dao.
Kit

qua da chgn dugc cac ddng Nang Huong ddng 2, ddng 9; Nang
Thom Chg Dao 5 cd nang
suit
cao hom
18
% so vdi
quin thi
gdc, nhung van
giii:
dugc
nhirng dac tinh quy cua gidng.
17
3.
MUC TIEU CUA DE TAI
- Phuc hdi va phat triln gidng lua dac san Nanh Chdn,
nhit
la cac dac tinh
phim chit
rieng biet.
- Xay dung qui trinh va md hinh san
xult
lua dac san Nanh Chdn cd hieu qua cao, nang
,
suat dat 4,0-4,5 t/ha,
Igi
nhuan tang jt
nhit
15%
so vdi lua thudng.
- Nang cao y thuc bao tdn san vat dja phuong, gdp

phin
phuc vu cdng tac du ljch tinh
nha, tien tdi xay dung thuong hieu san
phim
gao dac san Nanh Chdn cho tinh.
- Bd sung thdng tin va vat lieu di truyin cho cac chuong trinh lai tao gidng lua
chit
lugng cao.
4.
NOI DUNG VA PHU'ONG PHAP THU'C HIEN
4.1 Noi dung
1) Ndi dung 1: Dilu tra, khao sat hien trang san
xult liia
va thu thap ngudn vat lieu
gidng Nanh Chdn.
+ Dilu tra hien trang: thuc hien theo philu cau hdi soan
sin,
qui md 120 philu dilu
tra/ 3 xa/ 2 huyen-thj (xa Hda Long, thj xa Ba Rja va xa An
Nhit,
thi
trin
Long
Dien, huyen Long Dien).
+ Thu thap ngudn vat lieu
liia
Nanh Chdn: khao sat tren rudng san
xult
d cac dja
phuong trong va ngoai tinh, cac don vj nghien

ciiu
cdn luu
mlu
gidng trong va
ngoai nude.
2) Ndi dung 2: Thanh lge, phuc trang gidng
liia
Nanh Chon: i) Thanh lge trong phdng;
ii) Chgn
Igc
ddng thuin; iii) Chgn lge phuc trang; iv) San
xult
hat gidng sieu
nguyen chung va nguyen chiing.
3) Ndi dung 3:
Thii
nghiem cdng thuc bdn phan
phii
hgp va hoan thien qui trinh ky
thuat canh tac gidng
liia
Nanh Chdn tai tinh
Ba
Rja-Vung Tau.
4) Ndi dung 4: Chuyen giao ket qua nghien
ciiu:
i) Hdi thao thuc dja; iii) Tap
huin
ky
thuat san xuat; iii) Xay dung rudng md hinh.

4.2
Phuong
phap
4.2.1
Phuangphdp
diiu tra, khdo
sdt:
xem phan phu luc "Bao cao ket qua dieu tra hien
trang san xuat
liia
d BR-VT".
4.2.2 Phuang phdp chpn
Ipc
phuc hdi gidng
Ida
Nanh Chdn
- Ap dung tieu chuan nganh TCN 554-2002 trong xac djnh va md ta gidng gdc.
- Ap dung tieu chuan nganh 10 TCN 395-2006 trong chgn Igc phuc trang gidng sieu
nguyen chung tir rudng san xuat qua 3 the he
Go
- G\-
Gi-
Ap dung chgn Igc theo cdng
thirc tinh gia trj trung binh quan the (X) va do lech chuan (s) nhu sau:
18
X = (Ixi)/n; s = (V
X(xi
- X)Vn
Chgn cac ca the co gia tri trung binh trong khoang X ± s, voi:
(X:

gid tri trung hinh qudn thi, n:
s6
cd thi theo
doi,
xi: ki
hieu ciia
cd thi thu i)
- Ap dung cac tieu chuin nganh 10 TCN 342-2003 va TCN 404-2003 va tieu ehuln
qudc gia TCVN
1776-2004
trong kilm djnh
chit
lugng rudng gidng, hat gidng lua.
- Chgn lge ddng thuin va chgn lge
quin
the ddi vdi gidng dja phuong theo phuong
phap cua
B.D. Singh, 1986.
- Phuong phap danh gia cay lua theo tieu chuin ciia IRRI, 1996 (Standard Evaluation
System for Rice) va
10
TCN 558-2002 cua Bd NN & PTNT, thuc hien trong dilu kien
ddng rudng, nha ludi va phdng thi nghiem
- Phuong phap phan tich pham
chit:
ham lugng protein (Micro Kjieldahl), ham lugng
amylose (phuong phap cua Sadavisam & Manikam, 1992), do
bin thi GeUphuong
phap
ciia

Khush and at el. 1979), do hoa kilm (IRRI, 1996).
- Danh gia tinh chdng chju
rIy
nau (trong ldng ludi, nudi
rIy
trong dilu kien nhan tao)
va benh chay la (nuong ma dao dn) theo phuong phap IRRI, 1980.
- Phuong phap thdng ke trong thi nghiem va thu nghiem so sanh: Ducan, T-test, tren
cac
phin mim
EXCEL,
IRRISTAT,
MSTA T-C.
4.2.3
Phuangphdp
thu
nghiem
cdng thuc
bdn
phdn
- Thiet ke cdng thirc thir nghiem dua tren
kit
qua phan tich
dit,
dac dilm gidng, cac
cdng trinh nghien cim ve gidng va qui trinh canh tac cac
liia
dac san dja phuong khac
d cac tinh phia Nam.
- Thu nghiem dang Id rdng (200

m^/cdng
thiirc) va thi nghiem chinh qui, lap lai 3
lln
da
dugc thuc hien; sd lieu dugc phan tich, so sanh sai khac
bing trie
nghiem T-test,
Duncan tren phan mem EXCEL va MSTA
F-C.
4.2.4
Phuangphdp
chuyin giao kit qud nghiin
ciiru
- Ket hgp nhieu phuong phap va phuong tien chuyen giao ky thuat: in an tai lieu ky
thuat, tap huan, hdi thao chuyen de va tham quan danh gia md hinh thuc te.
- Ap dung phuong phap nghien cuu cd
sir
tham gia
ciia
ndng dan,
sii
dung ndng dan
kha, gidi lam cau ndi trong viec thdng tin va chuyen giao ket qua nghien
ciiu
den
ngudi san xuat.
- Phdi hgp vdi chinh quyen dja phuong, co quan quan ly nganh, Khuyen ndng va Hdi
Ndng dan trong viec tuyen truyen, cung cap cac thdng tin lien quan den san xuat va
chii
truong cua tinh trong vice phuc hdi gidng

liia
dac san Nanh Chdn.
19
5. KET QUA
TH^rc
HIEN
5.1 Dieu tra hien trang san
xuSt
lua va thu thap
ngu6n
vat lieu giong Nanh Chon
5.7.7
Khao sdt chpn diim nghiin
ciiru
vd
ddnh
gid dgc diim ddt trdng lua
- Dja diem khao sat: xa Hoa Long, thj xa Ba Rja va thj
trin
Long Diln, xa An Ngai, xa
An Nhat thude huyen Long Diln
- Muc tieu khao sat: Chgn dilm bd tri thi nghiem va phat triln gidng
liia
Nanh Chdn
thoa man tieu chi: 1) Dja hinh, chan
dit phii
hgp; 2) Hien cdn trdng gidng
liia
dja
phuong trong vu

miia;
3) Da timg trdng gidng lua Nanh Chdn va hien tai ngudi trdng
Ilia
cd nhu cau va mong mudn dugc phuc hdi phat triln lai gidng
liia
nay; 4) Dugc
chinh quyen dja phuong ung hd.
-
Kit
qua khao sat, chgn dilm thi nghiem:
+ Td chirc khao sat va thu mau dat (10
mlu)
tai cac xa Hda Long, Long Toan va
phuong Kim Dinh, thj xa Ba Rja; xa An Ngai va thj
trin
Long Diln, huyen Long
Diln; xa Phudc Ldc Thg, huyen
Dit
Dd.
+ Nhan xet: Cac diem khao sat neu tren deu cdn san
xult liia
dja phuong trong vu
Miia
tuy dien tich khdng dang ke. Cac gidng
liia miia
cdn trdng gdm: Thom sdm,
Trang Tep, gidng nhap ndi Khao Dawk
Mali-105
(KDM 105), Mashuri. Gidng
Mashuri va Thom sdm

chii
yeu trdng tren chan rudng cao nhd nude trdi,
diit
nude
sdm d xa Long Tan, Thj tran Long Dien va xa Hda Long. Chan rudng cao
diit nude
sdm khdng thich hgp cho cay
liia
Nanh Chdn do gidng nay chin mudn (den cudi
thang 12 hang nam). Chan rudng thap hoac cao trung binh, dugc tudi hoac nhd
nude trdi nhung dut nude tre d thj tran Long Dien va xa An Nhat la kha thich hgp
de trdng gidng Nanh Chdn.
- Ket qua phan tich, danh gia dac tinh dat trdng
liia
+ Dat san xuat hoi chua vdi pH thap den hoi thap d tat ca cac mau phan tich
+ Thanh phan co gidi:
8/10
diem phan tich cd thanh phan co gidi la thjt nhe pha cat,
rieng diem 3 la dat set va diem 4 la dat cat
+
Chit
hum co: trung binh d ca 10 mau phan tich
+ Dam (N) tdng sd: diem 7& 8 giau, cac diem cdn lai trung binh; N de tieu trung binh
d dilm
1
va 10, cac diem cdn lai ngheo N
+ Lan (P2O5) tdng sd: khac nhau kha rd giiira cac diem, diem 1 va 3 la trung binh,
dilm 2, 7, 8, 10
rit
giau, cac diem cdn lai hoi thap. Lan de tieu (dt) d diem 2 kha

cao,
dilm 5 va 6 trung binh, cac diem cdn lai deu thap. Tai eae diem giau lan, cd
kha nang do lugng lan dugc bdn du thira nen cdn tdn du trong dat.
+ Kali (K2O): Kali tdng sd
rit
ngheo d tat ca cac diem; K de tieu trung binh d diem 3,
4,
cac dilm cdn lai dlu ngheo. Vi da phan la dat cat va khdng cd ngudn
phii
sa hang
nam bdi dap nen dat bj thieu K.
+ Ddc
chit:
Chi sd EC va ndng do mudi tan thap chimg td dat it bj anh hudmg man;
-
dgc
chit
Al^*
cao d dilm 3, cdn lai deu thap; ddc chat
Fe^""
cao d hau het cac diem
chimg td
dit
anh hudng phen sat la
chii
yeu va d
miic
do cd kha nang gay ddc cho
lua.
20

Bang 1:
Ki hieu
1
2
3
4
5
6
7
8
9
10
Ki hieu mau dat khao sat, phan tich
Diem lay mau
Xa An Ngai, Long Dien
Xa Phudc Lge Thg,
Dit
Dd
Phudmg Kim Dinh, Ba Rja
TT Long Dien, Long Dien
Xa Long Tdan, Ba Rja
TT Long Dien, Long Dien
Xa Hda Long, Ba Rja
Xa Hda Long, Ba Rja
Xa An Ngai, Long Dien
Xa An Nhat, Long Dien
Dja hinh
cdtudi
nude trdi
dat nhiem man

dat thap
dat thap
cdtudi
cdtudi
dat thap
cd tudi
cd tudi
Nhdm gidng hoac
gidng Ilia san xuat
Ilia
cao san
Mashuri
KDM 105
Ilia miia
lua
miia
Ilia cao san
Ilia cao san
Ilia miia
Ilia cao san
~
Ilia
cao san
Bang 2: Ket qua phan tich mau dat tai cac diem khao sat
TT
1
2
3
4
5

6
7
8
9
10
pH
(KCl)
4,10
4,74
3,55
4,48
3,76
4,13
4,20
4,17
4,39
4,04
C/HC
(%)
2,24
2,12
3,00
2,00
2,34
3,45
2,26
3,93
1,81
2,75
Cat

(%)
73
88
44
95
79
78
89
83
83
55
Thit
(%)
3,0
2,0
8,0
1,0
4,0
5,0
1,0
2,0
3,0
32
Set
(%)
24
10
48
4,0
17

17
10
15
14
13
Ai^;
(cmoC/kg)
0,22
-
5,60
-
1,52
0,12
0,48
0,08
-
0,60
Fe^^
(mg/kg)
1788
3,08
1180
69,7
333
854
830
1065
81,1
2265
TT

1
2
3
4
5
6
7
8
9
10
Nts
(%)
0,126
0,129
0,154
0,115
0,123
0,138
0,192
0,207
0,112
0,158
P205tS
(%)
0,109
0,219
0,101
0,028
0,063
0,095

0,212
0.165
0,107
0,180
KaOts
(%)
0,033
0,034
0,040
0,023
0,039
0,043
0,033
0,036
0,025
0,031
Ndt
(mg/kg)
65
34
38
24
40
44
56
53
35
65
Pdt
(mg/kg)

7,88
196
4,94
37,1
52,2
57,5
9,51
11,0
8,79
4,77
Kdt
(mg/kg)
34,4
23,4
172
94,8
19,8
25,3
21,6
19,8
45,5
27.1
EC
(uS/cm)
38,6
32,7
139
45,2
27,6
51,4

23,0
43,9
36,4
25,8
TMT
(%)
0,028
0,033
0,029
0,010
0,011
0,020
0,014
0,020
0,006
0,192
Ghi chu: CHC: chat hiru co,
ts:
tdng sd, dt: dl tieu,
TMT:
tdng mudi tan
21
* Nhan xet: Dat trdng lua tai cac dilm khao sat d mirc dinh duong tmng binh cho
din
hoi
ngheo, rat it hoac khdng anh hudng man nhung bj anh hudng phen.
Kit
qua khao
sat, danh gia
chit dit

cho
thiy
cd 9/10 dilm
phii
hgp vdi viec canh tac cac giong
liia
m^iia
dja phuong, it chju phan,
dit
cd du tnic nhe, ham lugng
chit
hiiu co
tmng
binh,
dat hoi chua va cac dudng
chit
d mirc tmng binh hoac hoi ngheo, dac biet la lan va
kali.
Dieu
ki§n dit
trdng gidng Nanh Chdn d BR-VT
tmyin
thdng cd nhilu net tuong tu
nhu d mdt sd noi trdng lua thom
chit
lugng cao (Nang Thom Chg Dao, Nang Huong,
Tau Huong) d Long An, TP. Hd Chi Minh, tuy vay mirc do bj anh hudng man it hon.
5.1.2
Thu
thdp mdu lua

Nanh
Chdn
- Thu thap thdng tin thir dp, so dp: Thdng tin vl ngudn gdc gidng, ljch sir san
xult
liia
Nanh Chdn va co cau gidng lua hien tai (cdn san
xult
lua
miia
dja phuong). Tren co
sd cac thdng tin thu nhap, cac td cdng tac thuc hien dl tai da khao sat thuc dja cac
vimg trdng lua dja phuong tai Ba Rja-Vung Tau, TP.HCM, Ddng Nai,
Tly
Ninh,
Long An va
Bin
Tre trong khoang thdi gian tir thang 10-12 nam 2005.
- Khao sat, thu thap
mlu
gidng ngoai san
xult
+ Td cdng tac khao sat thuc dja da
din
cac huyen trong tinh Ba Rja-Vung Tau va cac
viing trdng
liia miia
d TP.HCM, Ddng Nai, Tay Ninh, Long An,
Bin
Tre va xac
djnh khdng cd dau hieu gidng

liia
can thu thap (Nanh Chdn) cdn tdn tai trong san
xuat. Tai cac dja phuong tren cac gidng
liia miia
cdn trdng rai rac la Nang Thom
Chg Dao, Tau Huong, Nang Huong, Nhd Sdm, Thom Sdm, Tieu Ddi, Tring Tep,
Mdng Chim, Huyet Rdng va mdt sd gidng nep.
C)
Ba Rja-Vung Tau cd cac gidng
Nang Thom Long Dat, Trang Tep, Mahsuri, Khao Dawk Mali.
+ Da phan cac lao ndng tmdc day xac nhan da timg trdng gidng liia Nanh Chdn deu
khdng md ta dugc dac diem gidng, cac nhan xet chung la: day la gidng dac biet
ngon com nhung nang suat thap, nhiem ray, than hoi xde, ra yeu; hat lua nhd, vd
thdc dudi hat keo dai, hoi nhgn va cong (quat dudi).
- Khao sat, thu thap mau gidng tir ngan hang gen: dua tren cac mdi quan he va hgp tac
song phuong trong va ngoai nude trong trao ddi va khai thac ngudn gen gidng cay
trdng, de tai da thu thap dugc 7 mau gidng va nhan dugc 1000 ddng
liia
cd ten ggi la
Nanh Chdn tir cac don vj nghien
ciiu,
trong dd gdm:
+ 540 ddng tir ngan hang gen cua Vien KHKTNNMN (VN) tir
3 mlu
gidng
+ 320 ddng tir ngan hang gen
ciia
Vien
Liia
DBSCL (VL) tir 2

mlu
gidng
+
140 ddng tir ngan hang gen
ciia
Vien Nghien ciru
Liia
Qudc te (IRRI) tir 2 mau
gidng
5.1.3
Diiu tra hiin
trgng
sdn xudt lua
viing
nghiin cuu
- Muc tieu:
+
Nim bit
thuc te san xuat lua d viing nghien
ciiu:
co cau gidng, tap quan canh tac,
thdi vu, thj hieu tieu diing, hieu qua san xuat, tinh hinh ap dung tien bg ky thuat
(TBKT) va nhu cau can tac ddng, bd sung de nang cao hieu qua san xuat.
22