summary of doctoral thesis study on breeding medium maturity maize hybrid with high yield for southeast region and central highland of vietnam

MINISTRY OF EDUCATION
AND TRAINING

MINITRY OF AGRICULTURE
AND RURAL DEVOLOPMENT

VIETNAM ACADEMY OF AGRICULTURAL SCIENCES

VU NGOC QUY
STUDY ON BREEDING
MEDIUM MATURITY MAIZE HYBRID
WITH HIGH YIELD FOR SOUTHEAST REGION
AND CENTRAL HIGHLAND OF VIETNAM

Ranch of study: Genetic – PlantBreeding
Code: 62.62.01.11

SUMMARY OF DOCTORAL THESIS

Hanoi– 2014


This theisis is completed at:
VIETNAM ACADEMY OF AGRYCULTURAL
SCIENCES

Science supervisor:

1. Dr. Mai Xuan Trieu
2. As. Prof. Dr. Nguyen The Hung
Critic 1: ......................................................................

Critic 2: ......................................................................
Critic 3: ......................................................................
The thesis will be defented before Council for
thesis assessment at Institutional level held at
Vietnam Academy of Agricultural Sciences
At ......hour .......minute, day......month......year 2014
This Thesis can be referred to at:
1. National Library
2. Library of Vietnam Academy of Agricultural
Scienses
3. Library of Naional Maize Research Institute


1

INTRODUCTION
1. URGENCY OF THE THESIS
Southeast and Central Highlands are two large commodity
maize producing regions in Vietnam’s southern provinces. In 2012,
the average maize yield in these regions was 5.13 tons/ha, (in which
Southeast region and Central Highlands was 5.62 tons/ha and 4.98
tons/ha), by 119,4% and 103,4% compared with country’s maize
yield (4.30 tons/ha) and the global maize yield (4.98 tons/ha),
respectively.
In order to improve the efficiency of maize production in
Southeast region and Central Highlands through actively supplying
seeds with cheap price, it is essential to implement the thesis “Study
on breeding medium maturity maize hybrids with high yield for
Southeast region and Central Highlands”
2. PURPOSES OF RESEARCH

Breeding and selecting some inbred lines and promissing
crosses for maize breeding and production program in Southeast and
centre Highlands
Breeding new hybrid varieties with medium maturity (90- 96
days), high yield, good quality, suitable to conditions in these
regions..
Determining some cultivation technologies such as plant
density and row spacing, fertilzer doses for new hybrids with the
purpose of introducing and transfering inovative techniques for
farmers in these regions
3. THE PRACTICAL AND THEORETICAL SIGNIFICANCES
3.1.Theoretical significances
Supply additional data, scientific information and the ability


2
to apply the method to selection inbred lines for maize hybrid
breeding.
Implementing scientific data on hybrid maize and cultivation
techniques in ecological conditions of Southeast region and centre
Highlands.
3.2. Practical signficances
8 inbred lines namely IL3, IL4, IL26, IL28, IL50, IL55, IL60
and IL61 are identifed with good charateriesties: well growth and
development, good resistance serving as promissing inbred lines for
the maize breeding program in the SouthEast region and Central
Highlands.
Thesis was identified two maize hybrids LVN68 and DP113
with medium- dated growth duration, well growth and development
ability, good tolerance to unfavorable conditions; for high and stable

yield, adaptation to ecological conditions of Southeast and Central
Highlands.
Identification of suitable planting density of 66,600 plants/
ha with row spacing of 60 cm x 25cm and the optimal dose of
fertilizer of 180N - 80P2O5 - 80 K2O (kg/ha) for maize hybrid
LVN68 in Southeast region and Central Highlands.
4. MATERIALS AND SCOPE OF RESEARCH
4.1. Materials
Inbred lines are developed from different gemplasm
resourses
Hybrids are develpoed from the selected inbred lines.
The suitable cultivation methods are used for promising
hybrid combination.
4.2. The scope of research


3
Conducting

field

experiments,

including

experimental

evaluation to select test topcross and dialell hybrids, , breeder testing
(compared to promissing hybrids), VCU tesing; density and dose of
fertilizer experiments..

5. THE NEW CONTRIBUTIONS OF THE THESIS
The thesis was identified 8 inbred lines which have high
combining ability, added to the gemplasm resourses of MRI. The
research also developed two corn hybrids namely LVN68 and
DP113 with suitable plant density and fertilizer doses for
contributing to maize production in Southeast region and central
Highlands.
6. THE THESIS STRUCTURE
The thesis consists of 155 pages, 67 tables, 16 pictures and
photographs: Introduction (3 pages); Chapter 1: Review of literature
(38 pages); Chapter 2: Materials, content and research methods (10
pages ); Chapter 3: Results and discussion (101 pages); Conclusion
(2 pages), References include 163 documents with 51 Vietnamese
documents and 100 English documents and 1 Bulgarian document.
11 wenside documents Three scientific papers related to the thesis
contents have been published in domestic and international scientic
journals.
CHAPTER 1:
LITERANTURE REVIEWS
1.1 THE ROLE OF MAIZE IN THE NATIONAL ECONOMY
Acoording to Ngo Huu Tinh (1997), maize was used as the
main food for 1/3 world population. Maize is the staple food for
people in Southeast Africa, West Africa, South Asia, Central and
South America, etc.


4
In addition to its role as food crops, corn is the main
ingredient in animal feed, is export product, and high nutritional value
of food and raw material for the processing industry, especially

ethanol industry to replace fossil energy depleted.
1.2. SITUATION OF PRODUCTION AND USE OF HYBRID
MAIZE VARIETIES IN THE WORLD AND VIETNAM
1.2.1 Situation of production and use of hybrid maize varieties in
the world
As compared to wheat and rice, corn yield is ranked the first
in yield and the second in productivity [147]. Maize plays an
important role in the economy, so that maize production in the world
has always been being paid attention and development by
Goverments. Although in the current years, maize area in the wold is
not increased as compared to the end of the twentieth century, due to
the limited cultivation lands but the world corn production has
continued to grow. The main reason is due to the application of
improved hybrid varieties and the advanced farming techniques in
production. In 2001, maize areas worldwide is of 140,2 million
hectares with an average yield of 4,3 tonnes / ha; and the total
production of 600 million tons. The percentage of maize acreage
accounted for 20 % of the total grain crop areas [ 38 ]. The average
annual growth rate of maize production worldwide in the period of
2000 - 2010 in area, yield, and productivity is of 1,8 %, 2,1%, and
4,3%, respectively. By 2012 , corn acreage worldwide is 176,9 million
ha with average yield of 4,94 tons / ha (decreased 0,4 tons / ha as
compared to that in 2011) and production reached 875 million tons
[147 ].


5
1.2.2. Utility of maize hibrid variety and production in Vietnam
Hybrid maize playsa major role in increasing productivity and
yield of corn Vietnam. Period of 1960 – 1980, corn yield of Vietnam

was obtianed by 0,8 to 1,1 tons / ha for local varieties with outdated
cultivating techniques. By the year 1990, maize yield was increased
up to 1,5 tons / ha, due to starting utiliztion of improved varieties.
Hybrid maize has contributed greatly to increasing corn yields in
Vietnam. In 1991, hybrid miaze area was extimated by less than 1%
of the 447,000 hectares, in 2000, hybrid maize was grown on an
area, equal to 65% of total area and average corn yield reached to
2.75 tons/ha and in 2012 , with an area of 1118,2 thousand hectares
of maize, of which more than 95 % of the area is the used fo hybrid
varieties. The success of hybrid corn program has significantly
contributed in bringing corn yields achieved national average of 4.3
tonnes/ha.
1.2.3 Maize production in Southeast region and Central
Highlands
Southeast region and Central Highlands are the two largest
production of maize commodity.

These regions have a tropical

climate and monsoon divided into two distinct seasons: the dry
season from November to April last year after year, The rainy season
from May to October, and cool west climate, favorable for crop
development, Average annual rainfall is about 1500-2000 mm. In
2012, the average maize yield in these regions was up to 5.13
tons/ha, (in which Southeast region and Central Highlands is 5.62
tons/ha and

4.98 tons/ha), increased by 119,4% and 103,4%

compared with national maize yield (4.30 tons/ha) and the global

maize yield (4.94 tons/ha).


6
With the aim of developing strong Vietnamese hybrid corns
in two corn producing areas of the major commodities in the
southern provinces, it is necessary to promote the breeding for these
regions. The deployment of inbred line breeding, hybrid testing, and
identification of suitable cultivation methods to improve efficiency
in maize production are essential requirements for maize production
in Southeast and Highlands.
1.3. HETEROSIS AND ITS APPLICATION IN MAIZE BREEDING
1.3.1 The concept of heterosis
Heterosis is a phenomenon of offspring heterozygous at the
first generation capable of growth, development, resilience,
adaptability, productivity, etc, outperformed with their homozygous
parents.
1.3.2 Method of determining heterosis
Heterosis of F1 hybrids is based on comparing the medium
of parent heterosis (HMP) or the best of parent heterosis (HBP), with
control hetetosis (Hs).
1.4. INBRED LINE AND ITS BREEDING METHODS
1.4.1.Definition of inbred lines
Inbred line is a relative concept for selfing lines with the
high homozygous and stable for characteristics, with maize, usually
after 7-9 times selfing.
1.4.2 Materials for inbred lines
primery materials are the foundation of the plant breeding
work. Materials for developing inbred lines are diverse, including
local varieties, synthetic varieties, gene pool, populations, hybrid...

With each different type of material, inbred lines created are
different.


7
1.4.3 several methods to develop maize inbred lines
Some methods to produce the inbred lines were developed
by scientists as Sprague and Eberhart(1955)
+ The standard method (Selfing): This method was proposed
by

Shull

(1909,1910);

sib

or

fullsib

mehtod;

Integrated

domestication Method; homologous line breeding; Backcross
method. Beside the traditional method as metioned above, there are a
number of methods to create a new line developed like selective
gametes, doubled haploid lines generated by anther culture or
unfertilized ovules.

1.4.4. Line evaluation and its method
Inbred lines are evaluated at the same time pure line
breeding. This is an indispensable work and be relative to the effect
of maize breeding, Through line evaluation, breeders can select
desirable inbred lines and give approach to use those lines in hybrid
maize breeding.
1.4.4.1 The concept of combining ability
Combining ability expresses the response of inbred lines via
crossing. Sprague and Tatum (1942) devided combining ability into
2 group: General combining ability (GCA) and specific combining
ability (SCA), To evaluate combining ability of inbred lines, the
breeder uses 2 methods: Topcross and Diallel cross.
1.5. STUDY OF CLASIFICATION OF GROWTH DURATION
AND FARMING TECHNIQUE FOR MAIZE CULTIVATION
1.5.1 Classification of growth duration in maize
1.5.2.Research on the plant density and spacing of maize in the
world and Vietnam
1.5.3 Research of fertilizer influence to maize production


8
CHAPTER 2:
MATERIALS, CONTENT AND RESEARCH METHODS
2.1. MATERIALS
Tabe 2.1. List of inbred lines
No Name

Graphic
origin

Lines group I
1 IL1
Vietnam
2 IL2
Vietnam
3 IL3
Vietnam
4 IL4
Vietnam
5 IL5
Vietnam
6 IL6
Vietnam
7 IL7
Vietnam
8 IL8
Vietnam
9 IL9
Việtnam
10 IL10 Việnnam
11 IL11
USA
12 IL12
USA
13 IL13
USA
14 IL14
USA
15 IL15
USA

Line group 2
46 IL46 Thailand
USA
47 IL47
USA
48 IL48
49 IL49 Vietnam
50 IL50 Vietnam
51 IL51 Thailand

No

Name

Graphic
origin

No Name

Graphic
origin

16
17
18
19
20
21
22
23

24
25
26
27
28
29
30

IL16
IL17
IL18
IL19
IL20
IL21
IL22
IL23
IL24
IL25
IL26
IL27
IL28
IL29
IL30

USA
USA
USA
Thailand
Thailand
Thailand

Thailand
Thailand
Thailand
Thailand
Thailand
Philippin
Philippin
Philippin
Philippin

31 IL31
32 IL32
33 IL33
34 IL34
35 IL35
36 IL36
37 IL37
38 IL38
39 IL39
40 IL40
41 IL41
42 IL42
43 IL43
44 IL44
45 IL45

India
India
India
India

India
China
China
China
China
China
China
China
China
China
China

52
53
54
55
56
57

IL52 Thái land
USA
IL53
USA
IL54
USA
IL55
USA
IL56
USA
IL57

58
59
60
61
62
63

IL58
IL59
IL60
IL61
IL62
IL63

USA
Thailand
Thailand
Vietnam
Vietnam
Vietnam

Gemplasms consist of 63 inbred lines selected by selfing
method-from the dififrent material resources, The inbred lines have


9
selfed 9-12 times, growth duration of the lines from 85-100 days
depending on the season and divided into 2 groups:
The first line group: the lines were developed in Dan Phuong Hanoi before 2004,

The second line group: selected lines were developed in
Trangbom - Dong Nai Province from 2004 to 2008.
Checks in experiment
+ Breeder testing: C919, CP888, CP999
+ VCU testing: C919, CP888
2.2. CONTENT
- Evaluation on morphological characteristics of inbred lines
- Evaluation on combining ability and heterosis of inbredlines
- Testing promising maize varieties
- The study of farming techniques for hybrid variety LVN68,

2.3 METHODS
2.3.1 Method of field evaluation
According to Guideline of evaluation and data collection in
maize, comparison experiment of CIMMYT (1985) and National
Maize Research Institue.
2.3.2.Method of inbred line selection:
Using

of

traditional

method

(self

pollinated,

Sib,

backcross,,,)
2.3.3. Method of heterosis and combining ability
Identify heterosis, combining ability of seed yield of inbred
lines by topcross and diallel cross according to Omarov, NgoHuu
Tinh and Nguyen Dinh Hien (1996),
2.3.4 Official tesing of the promising hybrids


10
According to rule: “Maize Varieties-Procedure to conduct tests
for Value of Cultivation and Use” - 10 TCN 341 – 2006
2.3.5 Data analysis
Data were computed and analyzed in microsoft excel,
IRRISTAST software version 4.0 and qualitities genetic software
program (Ver 2,0 Nguyen Dinh Hien, 1996),
2.4. TIME AND LOCATION,
2.4.1 location
Variety selection experiment, lines assessment, crosses
evaluating, genetic diversity analysis were conducted at National
Maize Research Institure
Official testing: implemented by network of National Centre
for Plant and Fertilizer Testing (NCPFT) southern region.
2.4.2. Times
- Materials collection and its evaluation 2002-2010
-Selection, inbred line evaluation of lines, hybrid testing
combined from 2004 to 2008
-The experiments on plant spacing, ferrtilizer dose from
2010 to 2012
CHAPTER 3:

RESULTS AND DISCUSION
3.1. Result of inbred lines selection from different gemplasm
resources.
The selection and assessment of inbred lines have been
conducted since 2002. From 45 origin collected materials, by
adaptative assessment, 18

lines with good characteristic were

selected, they were : IL1, IL2, IL3, IL4, IL8, IL11, IL13, IL14, IL19,
IL20, IL22, IL24, IL26, IL27, IL28, IL31, IL33 and IL35,


11
From 18 new lines developed in trang bom district-Dongnai
province after two seasion (summer-autum and autum-winter 2008)
for testing, adaptive evaluation, some characteristics of agricultural
biological, 12 lines selected, they were : IL46; IL47; IL49; IL50;
IL54, IL55; IL56; IL57; IL60; IL61; IL62 and IL63,
The lines have many good characteristics and can be used
for maize breeding programs in Southeast and Central Highlands,
3.3 THE RESULTS ON COMBINING ABILITY VALUATION
OF INBRED LINES
3.3.1 The results on general combiming ability on the yield of lines
3.3.1.1 Result of first topcross
Through two seasons for topcross between 18 lines and 2
testers (DF2 and D6), The line which showed highest GCA value
was IL28 and followed by IL26, IL3, IL1 IL19, IL2 và IL4... The
lines IL4, IL1, IL26, IL3, IL19, IL13 and IL28 have high

combining ability variances.
Table 3.8. General combiming ability values on yield trial of the
18 lines and two testers in summer-autum and Autum-winter
2005 in district-dongnai provice
lines
No

Line
Name

Tester
ĝi

ĝj

Tester name

Summer
- Autum

Autum winter

Summer Autum

Autum winter

Summer Autum

6.774

6.899

T1(DF2)

-0.669
0.669
0.000

1

IL1

2

IL2
IL3

4.211
6.941

4.620
6.785

T2 (D6)
Ʃ

IL4

4.448
-2.911

5.304
-0.311

-2.571

-5.758

Summer autum season 2005
Edi = 1.144
Ed (di – dj) = 1.617

3
4
5
6

IL8
IL11

Autum
winter

0.802
0.802
0.000


12
7

8
9
10

IL13
IL14
IL19
IL20

-8.629
-7.226
5.918
-3.116

-9.096
-7.665
5.864
-3.020

11

IL22

12
13
14
15
16
17
18

IL24
IL26
IL27
IL28
IL31
IL33
IL35
Ʃ

-4.271
-7.106
6.519

-4.230
-6.941
7.712

-3.504
9.951
0.144
-2.819

-3.893
9.477
-0.481
-2.855

-2.467 -2.413
0.000

LSD0,05 line = Edi *t(0,05;70) =
1.144*1.994 = 2.281
Ecj = 0.381
Ed (ck – cl) = 0.539
LSD0,05 tester plant = Ecj * t(0,05;70
= 0.381* 1.994 = 0.759

Autum –winter season 2005
Edi = 1.084
Ed (di – dj) = 1.534
LSD0,05 lines = 2.161
Ecj = 0.361
Ed (ck – cl) = 0.511
LSD0,05 tester plant = 0.719

3.3.1.2 Result of second topcross expresiment
12 lines namely IL46, IL47, IL49, IL50, IL54, IL55, IL56,
IL57, IL60, which have good growth and development ability,
resistant to pests, high yielding were taken for topcross with 2 testers
DF2 and D6 in the Summer- spring and Autum- witer 2009.
The table 3.11 showed that: The lines which had high GCA
value were IL60, IL49, IL61, IL50 and IL55; the lines which had
high variance of SCA value were IL60, IL61 and IL49; the lines
which had both high GCA and SCA value were IL60, IL61 and IL49
Table 3.11. General combiming ability values on yield trait of
the 12 lines and tester in summer-autum and Autum-winter
2009 in district-dongnai provice
line
Tester

ĝi

No Line

ĝj

Tester name

name Summer Autum Summer
autum
winter
autum

Autum Summer
winter autum

Autum
winter

1

IL46

-4.695

-4.666

T1(DF2)

-3.079

-0.906

2

IL47

-1.453

-1.513

T2 (D6)

3.079

0.906

3

IL49

6.585

6.609

Ʃ

0.000

0.000

13
4

IL50

5.095

5.629

5

IL54

-3.483

-3.554

6

IL55

4.718

4.561

7

IL56

-6.818

-6.893

8

IL57

-6.623

-6.739

9

IL60

7.743

7.599

10

IL61

5.805

5.769

11

IL62

-5.333

-5.349

12

IL63

-1.540

-1.451

Ʃ

Summer –Autumn season 2009
Edi = 1.849
Ed (di – dj) = 2.616
LSD0,05 line = Edi x t(0,05;46) = 3.723
Ecj = 0.755
Ed (ck – cl) = 1,=.068
LSD0,05 tester = Ecj x t(0,05;46) = 1.520
Autumn-Winter season 2009
Edi = 1.046
Edi = Ed (di – dj) = 1.480
LSD0,05 line = Edi x t(0,05;46) = 2.106
Ecj = 0.427
Ed (ck – cl) = 0.604

LSD0,05 tester = Ecj x t(0,05;46) = 0.859

0,000

3.3.2 The results on evaluation of agro-morphological
characteristics and SCA of inbred lines and hybrids
3.3.2.1 The results of first Diallel experiment
Based on results of evaluation on agro-morphological
characters of 45 lines (developed before 2004) and the GCA on yield
traits of 18 lines through topcross in the Summer –Autumn and
Autumn –winter 2005 (First topcross experiment), 7 lines: IL1, IL2,
IL3, IL4, IL19, IL26, IL28, with good agro-morphological
characteristics and high GCA were selected for diallel cross in 2
seasons: Autumn-winter 2005 and Summer- Autumn 2006. Hybrids
C919 and CP888 were used as checks. 21 crosses were evaluated on
the agro-morphological characteristics, productivity, pet resistance
There were 21 crosses for evaluating on the agromorphological

characteristics,

productivity,

and

disease/pet

resistance, fresh quality... As a result, the cross of IL26 x IL28 was
the most promising, which has medium duration and plant height,
high yield, especially nice formed cob, high resistance to pests. This

14
cross have been continued to be breeder testing with the name was
TB68 and official testing with the name was LVN68.
Table 3.18. Weigth of 1000 grains , rate of grain/ear and yield
of crosses in Autumn-winter 2005 and Summer-Autumn 2006

No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

Crosses

IL1 x
IL1 x
IL1 x
IL1 x
IL1 x
IL1 x
IL2 x
IL2 x
IL2 x
IL2 x
IL2 x
IL3 x
IL3 x
IL3 x
IL3 x
IL4 x
IL4 x
IL4 x
IL19 x
IL19 x

IL2
IL3
IL4
IL19
IL26
IL28
IL3
IL4
IL19

IL26
IL28
IL4
IL19
IL26
IL28
IL19
IL26
IL28
IL26
IL28

P1000
grains(g)
Aut., Sum Win.
Aut

Grains/ear
( %)
Aut., Sum Win.
Aut

289.6
304.2
304.1
311.3
306.2
312.4
295.9
279.8

295.8
284.7
306.7
290.2
300.2
298.9
267.2
305.8
320.2
288.5
323.2
301.9
326.7
310.5
317.9

77.95
79.40
74.60
74.35
74.80
75.63
77.39
75.95
75.45
73.07
78.08
77.81
76.30
75.74

78.59
72.83
72.35
75.08
70.66
72.96
74.63
79.71
77.08

298.7
305.2
311.4
312.5
308.2
314.4
300.8
281.8
297.9
288.7
312.7
291.2
304.2
299.9
279.9
305.9
320.9
288.8
332.7
302.9

335.2
312.2
318.8

Yield
(Tones/ha)
Aut., Sum Win.
Aut

78.02 6.950 7.047
79.46 6.082 6.777
74.68 7.395 7.491
74.44 6.796 6.891
74.87 7.461 7.556
75.71 7.487 7.674
77.46 6.445 7.052
76.03 7.332 7.428
75.54 7.295 7.389
73.14 7.959 8.045
78.16 7.191 7.473
77.88 7.894 7.991
76.38 7.007 6.723
75.81 7.319 7.411
78.65 7.726 7.922
72.91 7.320 7.412
72.43 7.518 7.610
75.16 7.935 8.028
70.75 7.402 7.493
73.06 7.663 7.390
75.82 8.537* 9.000*

75.96 7.602 8.056
75.07 6.950 7.047
4.8
5.3
0.585 0.655

21 IL26 x IL28
22 C919 (Check1)
23 CP888 (Check 2)
CV (%)
LSD0.05
Note: (*) Yields exceeding probability control at P ≥ 0.95


15
The result in evalution of heterosis of cross from 7 lines
group I
The results showed that the heterosis of crosses was more
dominant than parental lines which were obtained in most of the
traits: growth duration, plant height, yield components and especially
productivity. In these trials, HBP was from 128.82 % to 202.32 %.
The highest was estimated by 202.32% for IL3 x IL28 cross and the
lowest was 128.82% for IL3 x IL26 cross.
3.3.2.2. The results of second Diallel cross:
Table 3.29. Weigth of 1000 grains , rate of grain/ear and yield of crosse

1
2

in Summer and Autumn Winter 2010 in Trangbom - Dong Nai

P1000 grains
Grain/ear
Grain yield
(gam)
(%)
(Tons/ha)
Cross
SumAuSumAuSumAuAu.
Win.
Au.
Win.
Au.
Win.
IL49 x IL50 304.1 299.6 78.84 77.63 7.402
7.303
IL49 x IL55 300.3 295.7 79.40 77.24 7.158
7.068

3

IL49 x IL60

4

IL49 x IL61

5

IL50 x IL55

6

IL50 x IL60

7

IL50 x IL61

8

IL55 x IL60

9

IL55 x IL61

No

1 10 IL60 x IL61
C919 (đ/c1)

301.2
292.0
324.2
338.5
310.3
310.3
310.3
320.3
325.0

299.5
288.4
320.7
335.7
308.7
305.7
305.7
318.7
318.6

CP888 đ/c2)

310.3

308.7

CV (%)
LSD0.05

77.97
77.50
77.49
76.28
78.95
76.72
76.21
77.34
79.48
78.14

78.08
78.46
77.87
76.40
79.73
76.87
76.77
77.29
78.49
77.42

7.989
7.424
8.093
9.104
6.844
7.837
7.724
7.965
8.047
7.545
4.8
0.635

7.757
7.393
7.955
8.749
6.755

7.739
7.605
7.849
7.876
7.409
5.6
0.585

Note: (*) Yields exceeding probability control at P ≥ 0.95


16
The data in table 3.29 showed that: cross IL50 x IL60 had
high yield and stability in both seasons (9.103 tons dry grain/ha in
Autumn-winter and 8.749 tons dry grain/ha in Summer-Autumn
season by check 1(C919) was 113.15% in Summer –Autumn season,
111.01% in Autumn-winter season and by checked 2 (CP888) in two
trials respectively were 120,55 and 118,00 %.
Through evaluating 10 croses from 5 lines in the second
diallel cross on the agro-biological characteristics, productivity,
resistance cross IL50 x IL60 was the most promising, especially
productivity and resilience. This cross have been continued to be
breeder testing with the name was TB80 and official testing with the
name was DP113.

The resul of heterosis evalution of crosses from 5 lines group
II
The results showed that the heterosis of crosses was more
dominant than parental lines which presented in most of the traits:
growth duration, plant height, yield components and especially

productivity. In this trial, HBP reach from 129,49 % to 182,73 %,
which the highest was IL55 x IL61 cross (182,73 %) and the lowest
was cross IL50 x IL61 (129.49 %),.
3.3. THE TESTING RESULTS OF PROMISING CROSSES
3.3.1. BREEDER TESTING
3.3.1.1 The result of breeder testing cross IL26 x IL28 (TB68))
Since Summer –Autumn seasons 2006, IL26 x IL28 (TB68)
cross has been tested at Trangbom-Dongnai and Eaka-DakLak. In
compared experiment, TB68 cross had average yield at two location
were 9.394 tones/ha (from 8.77 to – 9.770 tones/ha) higher than 2
checked variety C919 and CP999 from 14,66 to 19,76 % (table 3.37).


17
Table 3.37. Grain yield of TB68 at breeder testing (tons/ha)
Trangbomdongnai

No

Variety

Eaka-daklak

Sum- Aut- Sum- SumAut Win Aut Aut
2006 2006 2007 2006

AutWin
2006

Sum- Average

Aut
2007

1

TB68

9.47b 9.69b 8.95b 9.71b 8.77b

9.77a

9.39

2
3

C919 (Ch 1)

8.39 7.42 7.08

8.09

7.05

9.05

7.84

CP999(Ch 2) 8.69 7.93 7.61

8.69

7.40

8.84

8.19

CV (%)

6.0

6.8

6.6

7.1

8.4

LSD0.05

0.73 0.84 0.70

0.84

0.77

0.99

7.4

Notes (a ) Yields exceeding 1 in 2 probability control at P ≥ 0.95
( b ) Yields exceeding both probability control at P ≥ 0.95

3.3.1.2 The result of breeder testing cross IL50 x IL60 (TB80)
Table 3.40: Grain yield of TB80 at breeder testing (tons/ha)

No

1
2
3

Variety

TB80
C919 (Ch 1)
CP999(Ch 2)
CV%
LSD0.05

TrangbomEaka-daklak
dongnai
Aut- Sum- Aut- Aut- Sum- Aut- Average
Win Aut Win Win Aut
Win
2010 2011 2011 2010 2011 2011

8.99b

8.08
7.58
6.1
0.68

9.31b
7.79
7.63
7.8
0.91

9.02b
8.17
7.32
8.2
0.83

9.10 b
818
760
6.3
0.71

9.24 8.96 b
8.76 8.06
8.36 7.77
7.9
8.0
0.94 0.82

9.10
8.17
7.71

Notes (a ) Yields exceeding 1 in 2 probability control at P ≥ 0.95
( b ) Yields exceeding both probability control at P ≥ 0.95

Since Autumn-Winter season 2010 to Autumn-Winter
seasons 2011, IL50 x IL60 cross has been tested at TrangbomDongnai and Eaka-DakLak. TB80 had avegare yield in three seasons
experiment at two point was 9.10 tons/ha, hight than check variety


18
1(C919) and check variety 2 (CP888) from 11,35 to 18,06 % (table
3.40).
3.5.2 Basic test results on value of cultivation and use
3.5.2.1. The testing results on VCU of LVN68
Table 3.41. Grain yield of LVN68 on value of cultivation and
use testing (tons/ha)
Sea.

Location
Chau Đoc - Barịa Vung Tau

LVN68
(tons/ha)

%/
%/
chech 1

chech 2 LSD 0.05
(C919)
(CP888)
C919 CP888
Check
( tons/ha)

8.37 b
6.83 5.88 122.55 142.55 0.85
b
Trangbom - Đongnai
6.99.
5.88 5.71 118.88 122.42 0.69
AutCammy - Đongnai
7.53 a
6.65 6.19 113.23 121.50 0.97
Win.
b
7.51
5.82 5.03 129.04 140.00 0.97
2007 Ductrong -Lamdong
Buondon-Daklak
6.05 a
5.28 5.04 114.58 120.04 1.01
Avegare
7.29
6.09 5.57 119.67 130.92
b
Thongnhat-Dongnai
10.19

9.17 8.35 111.12 127.38 0.89
Win.
a
Cammy
Dongnai
10.10
9.24 8.18 109.31 123.47 0.90
-Spri
2007 Longphu - Soctrang
7.24
6.86 6.38 105.54 113.48
- Tanchau- Angiang
9.61
10.20 10.45 94.95
91.96
0.74
2008 Avegare
9.28
8.86 8.34 104.74 111.27
a
Chau Đoc - Barịa Vung Tau
8.19
7.52 7.02 108.91 116.67 1.12
b
Trangbom
Đongnai
7.38
6.35 5.78 116.22 127.68 1.08
Sum.
Cammy

Đongnai
6.34
6.00 5.67 105.67 111.82 0.90
a
Aut. Ductrong -Lamdong
8.54
7.89 6.43 108.24 132.81 0.96
2008 Buondon-Daklak
9.65 b
8.40 6.38 114.88 151.25 1.06
Avegare
8.02
7.23 6.26 110.90 128.20
Chau Đoc - Barịa Vung Tau 7.02 b
6.36 5.22 110.38 134.48 0.58
Trangbom - Đongnai
6.58 a
5.73 5.22 113.83 126.05 0.97
AutCammy - Đongnai
6.75 a
6.25 5.33 108.00 126.64 0.96
Win.
Ductrong -Lamdong
6.95 b
5.65 4.89 123.01 142.13 0.54
2008
Buondon-Daklak
7.95 b
6.28 6.64 126.59 119.73 0.91
Avegare

7.05
6.05 5.46 116.45 128.60
Notes (a ) Yields exceeding 1 in 2 probability control at P ≥ 0.95
( b ) Yields exceeding both probability control at P ≥ 0.95
Source: National Centre for Plant and Fertilizer Testing Southern Region


19
Basical asays to test the value of cultivar were implemented
by National Centre for Plant and Fertilizer Testing Southern Region
for the same breeder tessting. LVN68 short growth duration,
equivalent with check 1(C919), high uniformity, resistance to pest
and lodging, husk cover is relatively good, Avegare yield of LVN68
from 7.05 to 10.19 tones/ha higher than check 1 (C919) from 4.74 to
19.67 % and higher than check 2 (CP888) from 11.27 to 30.92 %.
LVN68 was provisionally released in 2010.
3.5.2.1. The testing results on VCU of DP113
Table 3.42. Grain yield of DP113 on value of cultivation and
use testing (tons/ha)
Sea.

Location

Tanthanh-Bảiavungtau
Cammy-Dongnai
Sum. Trangbom-Dongnai
Aut .
2012

Ductrong- Lamdong

Buondon - Daklak
Average
Tanthanh-Bảiavungtau
Aut. Cammy-Dongnai
Win.
2012 Trangbom-Dongnai

Ductrong- Lamdong
Buondon - Daklak
Average
Win. Tanthanh-Bảiavungtau
Spri. Cammy-Dongnai

20122013 Trangbom-Dongnai

Tanchau- Angiang
Average

LVN68
(tons/ha)

5.83
7.18a
6.88b
9.80b
8.82b
7.97
2.85
4.52a
6.07b

8.02
8.62b
6.40
4.42
9.14
8.48b
9.27a
7.68

Check
( tons/ha)

C919

CP888

5.62
6.99
6.08
9.78
7.75
7.50
3.79
4.01
4.99
7.63
7.27
5.86
3.86
8.35

7.21
9.15
7.14

6.51
6.26
5.80
8.97
6.80
7.04
3.22
3.59
4.58
7.75
6.15
5.37
6.36
8.25
7.45
7.45
6.77

%/
chech 1
(C919)

103.74
102.72
113.16
100.20

113.81
106.27
75.20
112.72
121.64
105.11
118.57
109.22
114.51
109.46
117.61
101.31
107.59

%/
chech 2 LSD 0.05
(CP888)

89.55
114.70
11.62
109.25
129.71
113.21
88.51
125.91
132.53
103.48
140.16
119.18

69.50
110.79
113.83
124.43
113.52

0.68
0.69
0.49
0.71
0.62
0.49
0.53
0.84
0.53
1.03
0.90
1.09
0.82
0.99

Notes (a ) Yields exceeding 1 in 2 probability control at P ≥ 0.95
( b ) Yields exceeding both probability control at P ≥ 0.95
Source: National Centre for Plant and Fertilizer Testing Southern Region


20
DP113 was VCU testing at 6 locations (Tanthanh-Bariavungtau, Trangbom-dongnai, Cammy-dongnai, Ductrong-Lamdong
and Tanchau- Angiang from Summer-Autumn 2012 and the end in
Winter Spring season 2012-2013 by National Centre for Plant and

Fertilizer Testing Southern Region.
Basical asays to test the value of cultivar were implemented
by National Centre for Plant and Fertilizer Testing Southern Region
for the same breeder tessting. DP113 had a good resistant to pets
and diseases, long ear and beutufull grain colour. Grain yield of
DP113 averaged from 6.40 to 7.97 tons/ha, higher than check 1
(C919) from 6.27 to 9.22 % and higher than check 2 (CP888) from
13.37 to 19.18 7 %. National Centre for Plant and Fertilizer Testing
Southern Region concluded that: “DP113 is promising cross” which
has been accepted for testing production.
3.4. THE RESEARCH RESULTS TO FARMING TECHNIQUES
FOR MAIZE HYBRYD LVN68 IN SOUTHEAST AND
CENTRAL HIGLADS
3.4.1. The result of density research for maize hybrid LVN68
The data in tables 3.45 and 3.48 showed that: Grain yield of
LVN68 varied with the plant density and changed from 8.008 to
10.486 tons/ha. In which, LVN68 gave the higtest yield at density of
66.6 thousand plants/ha with spacing of 60 x 25 cm, from 10.003 to
10.486 tons, higher than check variety (57.0 thousand plants/ha)
from 17,43 to 19,78 % in trangbom-dongnai and from 15,80 to
24,71 % in Ductrong-Lamdong area
Statistical analysis data showed that the yield from 3 levels of
plant spacing: 60 x 28cm; 60 x 22cm and 60 x 25cm exceeded to the


21
control at significant probability P ≥ 0. 95. With the density of 66.600
plants/ha and planting distance of 60 x 25cm, productivity showed the
highest and exceeding the other treatments in the probability P ≥ 0, 95
Table 3.45. Grain yield of different planting densities with maize

hybrid LVN68 in summer Autum and Autum –Winter 2010 in
Trangbom-dongnai province.
Sum - Aut 2010
Plant
Spacing
No.
density
Yield
%
(cm)
(Plants/ha)

1

60 x 30

2

60 x 28

3

60 x 25

4

60 x 22

5

70 x 25 (check)

55,500
59,500
66,600
75,750
57,000

CV (%)
LSD0.05

(tons/ha)

/check

Aut. - win 2010
Yield
(tons/ha)

%
/check

8.758
100.05 8.732
99.59
9.693* 110.72 9.711* 110.75
10.486* 119. 78 10.297* 117.43
9.099* 103.93 9.228* 105.25
8.754
100,00 8.768 100,00

7.9
7.2
0.303
0.334

Note: (*)Yields exceeding probability control at P ≥ 0.95
Table 3.48. Grain yield of different planting densities with maize
hybrid LVN68 in Ductrong-lamdong province in Winter –Spring
2011-2012 and Summer Autumn 2012.
Win –Spri
Plant
Spacing
2011-2012
No.
density
(cm)
Yield
%
(Plants/ha)

1
2
3
4
5

60 x 30
60 x 28
60 x 25
60 x 22

70 x 25 (Check)
CV (%)
LSD0.05

55,500
59,500
66,600
75,750
57,000

Sum- Autn
2012
Yield
%
(tons/ha) /check

(tons/ha)

/check

8.685
9.752*
10.108*
9.234*
8.729
6.6
0.409

99.50
8.008

99.83
111.72 9.306* 116.02
115.80 10.003* 124.71
105.78 9.073* 113.12
100.00 8.021 100.00
9.9
0.570

Note: (*) Yields exceeding probability control at P ≥ 0.95


22
3.4.2 The research result of fertilizer dose for maize hybrid
LVN68.
Table 3.51. Grain yield of maize hybrid LVN68 of different
fertilizer doses in Trangbom-dongnai in Autumn-Winter season
2010 and Winter –spring season 2010-2011.
Fom.

Fertilizer dose
(kg/ha)

CT1 120 N-80 P2O5-80 K2O
CT2 120 N-80 P2O5-100 K2O
CT3 150 N-80 P2O5-80 K2O
CT4
CT5
CT6
CT7

Winter-spring
2010- 2011
yield
%
yield
%
(tons/ha) /check (tons/ha) /check
7.744
95.02 7.578
91.92
7.965
97.73 7.924
96.12
Aut.-win. 2010

8.933*
150 N-80 P2O5-100 K2O
9.207 *
180 N-80 P2O5-80 K2O
10.057 *
180 N-80 P2O5-100 K2O
10.025 *
150N-80P2O5-60K2O (check) 8.150
CV (%)
3.8
LSD0,05
0.598

109.61
112.97

123.40
123.01
100.00

8.958 *
9.215 *
10.076 *
10.034 *
8.245
2.7
0.419

108.65
111.77
122.22
121.70
100.00

Table 3.54: Grain yield of maize hybrid LVN68 of different
fertilizer doses in Ductrong-lamdong in Winter –spring season
2011-2012 and Summer-Autumn 2012.
Fom.
CT1
CT2
CT3
CT4
CT5
CT6
CT7

Fertilizer dose
(kg/ha)
120 N-80 P2O5-80 K2O
120 N-80 P2O5-100 K2O
150 N-80 P2O5-80 K2O
150 N-80 P2O5-100 K2O
180 N-80 P2O5-80 K2O
180 N-80 P2O5-100 K2O
150N-80P2O5-60K2O (check)
CV (%)
LSD0.05

Win-spri
Sum –aut
2011- 2012
2012
yield
%
yield
%
(tons/ha) /check (tons/ha) /check
7.744
92.58
7.995 96.00
8.203
98.06
8.233 98.86
9.099 * 108.77 9.096* 109.22
9.399 * 112.36 9.327* 112.00
10.139 * 121.21 10.116 * 121.47

10.078 * 120.48 10.069 * 120.91
8.365
100.00
8.328 100.00
3.7
2.7
0.594
0.426

Note: (*)Yield exceeding probability control at P ≥ 0.95


23
The data in table 3.51 and 3.54 showed that: Grain yield
hybrid LVN68 at different fertilizer doses expressed big difference
ranging from 7.744 to 10.139 tons/ha. 4 fomualas gave yield
exceeding probability check at P ≥ 0.95 were CT3, CT4, CT5, CT6
in which the highest ones is CT5 fomuala and ranged from 10.076 to
10.139 tons/ha, higher than check (CT7) from 21.22 to 24.40 % in
Trangbom-dongnai and from 21.21 to 21.27 % in Ductrong-lamdong
and CT5 formula give the highest economic efficiency.
CONCLUSION AND RECOMMENDATION
1.CONCLUSION
1.1. 8 inbred lines namely IL3, IL4, IL26, IL28, IL50, IL55, IL60
and IL61 were identified with high general combining ability (GCA)
and specific combining ability (SCA), adaptable to ecological
conditions of Southeast and Highland. These inbred lines were the
first materials developed by NMRI for maize breeding program of
Southeast region and were the foundation of the maize breeding
projects of Southern provinces.

1.2. The heterosis of crosses was more dominant than parental lines
which presented in most of the traits: growth duration, plant height,
yield components and especially productivity. HBP reached from
128.82 to 202.32 %, in which IL3 x IL28 cross expressed the highest
heterotic value (202.32).
1.3. Results from the research were identified two maize hybrids
LVN68 and DP113 with medium- dated growth duration, growth and
development ability, good tolerance to unfavorable conditions; high
and stable yield, adaptation to ecological conditions of Southeast and
Highlands. LVN68 was provisionally released in November, 2010
and National Centre for Plant and Fertilizer Testing Southern Region