This document summarizes an MSc thesis that studied genetic variability in maize inbred lines in central Ethiopia. 25 maize inbred lines were evaluated in a 5x5 triple lattice design trial. A number of agronomic traits were measured including days to tasseling/silking, plant/ear height, leaf characteristics, tassel/ear traits, yield components and grain yield. Analysis of variance showed significant genetic variability for most traits. Estimates of variance components, phenotypic and genotypic coefficients of variation, heritability and genetic advance were also calculated to understand the genetic potential of the lines for selection and breeding. The study provides useful information on the nature and extent of genetic diversity present in the maize in

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GENETIC VARIABILITY FOR YIELD AND YIELD
RELATED TRAITS IN SOME MAIZE (Zea mays L.)
INBRED LINES IN CENTRAL HIGH LAND OF
ETHIOPIA
M. Sc. Thesis
By
Fekadu Korsa Hunde
Major Advisor Habtamu Zeleke (PhD)
Co-advisor Yohannes Petros (PhD)
May 31, 2014
Haramaya University

3. OUT LINES OF THE PRESENTATION
• INTRODUCTION
• MATERIALS AND METHODS
• RESULTS AND DISCUSSIONS
• SUMMARY AND CONCLUSSIONS
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4. 1. INTRODUCTION
Maize (Zea mays L.)
 has chromosome number 2n=20.
 is the most widely grown cereal in the world.
 is third cereal in the world after wheat and rice (Golam et al., 2011).
 belongs to the tribe Maydeae, of the grass family, poaceae
 is native to South America (Nagabhushan, 2008).
 is a widely cultivated crop throughout the world. E.g. USA produces almost half of the
worlds maize production
 other top maize producing countries are: China, Brazil, Mexico etc (Nadagoud, 2008).4

5. Maize growing areas in Ethiopia
 are broadly classified into four ecological zones, based on altitude and
annual rainfall (Leggese et al., 2012).
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S/N Ecological zones Altitude (masl) Annual rainfall
(mm)
1 Highland sub-humid 1800 - 2600 1000 - 2000
2 Mid-altitude sub- humid 1000 -1800 800-1500
3 Low altitude sub-humid bellow 1000 1200-1500
4 Low moisture 500 -1800 Less than 800
1. INTRODUCTION …

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The total production of some cereal crops in 2011/12 in (t/ha) :
Maize ranks 2nd after teff in area coverage and first in total production in Ethiopia
(CSA, 2012).
1. INTRODUCTION…
Key

7. Uses of maize in Ethiopia
Maize is consumed as a staple food in different forms:
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Maize
bread
roasted or
boiled
tella,
araki
nefro
injera
porridge
1. INTRODUCTION…

8. 1 INTRODUCTION…
 The study of variability, Heritability and Genetic advance are very
important for selection in plant breeding programs.
 Gap of the study
 No sufficient work has been done for understanding and describing the nature
and extent of GCV, PCV, heritability in broad sense, genetic advance, association
between yield and yield related traits of maize in bredlines developed for central
high land Ethiopia.
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9. Objective of the study
General objective
To find out the nature and magnitude of the genetic variability for
different traits of maize inbred lines.
Specific objectives
Estimate the variability, heritability and genetic advance as well as
genotypic and phenotypic coefficients of variation.
Assess the extent of association between yield and yield related
traits of maize.
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1. INTRODUCTION…

10. 3. MATERIALS AND METHODS
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11. 3.1 Description of the Research Site
 The experiment was conducted at Ambo Plant Protection Research Center
 June,3-December,30 during the main cropping season of 2013/14
 Located at Latitude of 8059' N and Longitude of 37051'E
 at the elevation of 2101 masl
 The average annual rainfall is 1242.90 mm
 maximum temperature of 27.63oC and minimum temperature of 10.13oC.
(Source: APPRC meteorological station, 2014)
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12. S/N Inbred lines Origin S/N Inbred lines Origin
1 AMH169-1 AMB11N37-LD-2 14 AMH169-75 AMB11N37-LD-248
2 AMH169-5 AMB11N37-LD-10 15 AMH169-81 AMB11N37-LD-262
3 AMH169-8 AMB11N37-LD-29 16 AMH169-86 AMB11N37-LD-273
4 AMH169-12 AMB11N37-LD-37 17 AMH169-87 AMB11N37-LD-274
5 AMH169-16 AMB11N37-LD-48 18 AMH169-92 AMB11N37-LD-284
6 AMH169-22 AMB11N37-LD-75 19 AMH169-98 AMB11N37-LD-290
7 AMH169-28 AMB11N37-LD-111 20 AMH169-113 AMB11N37-LD-323
8 AMH169-33 AMB11N37-LD-124 21 AMH169-114 AMB11N37-LD-325
9 AMH169-100 AMB11N37-LD-292 22 AMH169-115 AMB11N37-LD-326
10 AMH169-51 AMB11N37-LD-188 23 AMH169-116 AMB11N37-LD-327
11 AMH169-55 AMB11N37-LD-208 24 AMH169-117 AMB11N37-LD-328
12 AMH169-56 AMB11N37-LD-212 25 AMH169-50 AMB11N37-LD-184
13 AMH169-57 AMB11N37-LD-216 12
3.2 Experimental Materials
Source: All the inbred lines were taken from APPRC
25 maize inbred lines were used for the study

13. 3.3 Experimental Design and Trial Management
The study was carried out:
 5 x 5 triple lattice design.
 The plot size was 3m long and 1.5m wide ( net area =4.5m2 )
 consisted of two rows with 12 plants/row
 The spacing between the:
 rows = 75cm
 plants = 25 cm
 Plots=1.5m
 The two rows were used for data collection.
 Two rows were sown around the experimental field as border for protection.
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14. 3.3 Experimental Design and Trial Management...
 The plots were fertilized with the :
 UREA at the rate of 200 kg ha-1
 DAP at the rate 150 kg ha-1.
 Urea was applied in 3 equal splits. These are
1st :1/3 at sowing along with phosphorus dose.
2nd :1/3 at knee high stage and
3rd :1/3 at tasseling stage of the crop.
 Two seeds were planted per hill and then seedlings were thinned to one
plant at 4-5 leaf stage
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15. 3.4 Data Collected
 Five plants were taken randomly for recording observations of all the
quantitative traits except for days to 50 % tasseling and silking.
 Mean of five plants for each plot were worked out for each trait and used
for statistical analysis.
3.4.1 Quantitative traits
 Days to 50 percent tasseling
 Days to 50 percent silking
 Plant height (cm)
 Ear height (cm)
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16. 3.4.1 Quantitative traits…
 Number of Leaves per Plant
 Leaf Length (cm)
 Leaf width (cm)
 Number of tassel branches
 Ear length (cm)
 Ear diameter (cm)
 Number of kernel rows per ear
 Number of kernels per row
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17. 3.4.1 Quantitative traits…
 Number of ears per plant
 Thousand kernels weight (g)
 Grain yield per plant (g)
 Grain yield per hectare (kg)
 Above ground biomass yield per plant (g)
 Harvest index (%)
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18. Statistical Analysis
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3.5 Analysis of Variance
was carried out for all the traits by using procedures out lined by
Gomez and Gomez (1984)
 by using the SAS V.9.0 (SAS, 2002) soft ware.
 Mean separation for various traits were computed using LSD
at 0.05 and 0.01 of probability.

20. 3.6 Estimation of Genetic Parameters
3.6.1 Genotypic and phenotypic coefficient of variation
Genotypic variance (σ2g) = Msg- Mse
r
 Phenotypic variance (σ2p) = σ2g+ σ2е
Environmental variance (σ2е) = Error
PCV= GCV= Burton and De Vane (1953).
3.6.2 Heritability (H2)
Heritability in broad sense (H2) = (Vg/Vp ) x 100 (Hanson et al., 1956).
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100
2
X
X
p 100
2
X
X
g

21. 3.6.2 Heritability (H2)…
The heritability percentage was categorized as (Robinson et al., 1949), as follows.
 Low: 0-30%
Moderate : 30-60%
High: >60%
3.6.3 Genetic advance
 Was calculated by using the formula given by (Robinson et al., 1949)
GA =I * σp * H2
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22. 3.6.4 Genetic advance as percent of mean
GA as percent of mean = ( ) * 100
The GA % was categorized as:
 0-10 %: Low
10-20%: Moderate
20 % and above: High by (Johnson et al.,1955)
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X
GA

23. 3.7.1 Coefficient correlation (r)
rp and rg were computed by using the formula given by Webber and
Moorty (1952).
rp = Covxyp / (Varxp x Varyp)1/2
rg = Covxyg/ (Varxg x Varyg)1/2
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3.7 Association of Traits and Path Coefficient Analysis
3.7.2 Path coefficient analysis
Was estimated with the formula given by Dewey and Lu (1959).
r = pij+  jkik pr

24. 4. RESULTS AND DISCUSSIONS
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25. 4.1 Range and Mean Values
Traits Minimum Maximum
Value Line Value Line Mean SD(±)
DT 91.49 AMH169-5 114.51 AMH169-22 103.55 1.84
DS 89.61 AMH169-8 113.89 AMH169-22 105.99 1.73
PH 111.45 AMH169-12 200.86 AMH169-22 145.17 7.54
EH 44.06 AMH169-12 118.64 AMH169-22 67.29 7.03
NLPP 11.2 AMH169-28 16.73 AMH169115 14.42 0.51
LL 54.99 AMH169-33 83.05 AMH169-81 67.83 2.79
NTB 6.84 AMH169-8 23.04 AMH169-22 14.79 1.37
ED 3.29 AMH169-1 4.6 AMH169-86 3.83 0.39
NKRPE 10.67 AMH169-55 13.78 AMH169-33 12.22 0.69
NKPR 15.76 AMH169-75 31.87 AMH169-28 22.92 2.77
NEPP 0.97 AMH169-75 1.64 AMH169-51 1.2 0.25
LW 8.35 AMH169-75 11.27 AMH169-87 9.61 0.5
TKW 160.19 AMH169-28 354.32 AMH169-87 228.91 24.43
GYPP
47.37 AMH169-116 111.78 AMH169-55
75.48 15.79
GYPH 824.15 AMH169-1 3384.52 AMH169-55 2137.57 450.19
AGBYPP 414.94 AMH169-33 893.82 AMH169-87 657.98 127.26
HI 13.39 AMH169-22 36.78 AMH169-55 24.97 3.46 25
Generally , range and mean values indicated that, all the
studied traits showed wide range of variation among the
maize inbred lines .
Maximum variation
were observed in
Minimum variation
were observed in
lines AMH169-5 & AMH169-8
took the shortest DT and DS respectively
line AMH169-22 took
the longest DT and DS
respectively
Lowest Grain yield 0.82 tone/ha was
recorded in AMH169-1
The highest grain yield
3.4 tone/ha was recorded
in AMH169-55

26. 4.2 Analysis of Variance
Trait Mean squares
Replications df= 2 Genotypes df= 24 Error df= 74
Days to 50% Tasseling 32.173 69.054** 3.397
Days to 50% Silking 38.653 100.959** 3.005
Plant height (cm) 1628.013 809.597** 56.813
Ear height (cm) 1081.693 521.860** 49.471
Number of leaves /plant 0.272 4.048** 0.257
Leaf length(cm) 146.574 134.865** 7.795
Leaf width 4.330 1.709** 0.248
Number of tassel branches 18.150 37.023** 1.872
Ear length(cm) 11.658 10.924** 1.184
Ear diameter(cm) 0.894 0.339* 0.155
Number of kernel rows per ear 2.850 2.357** 0.478
Number of kernel per row 65.924 51.344** 7.683
Number of ear per plant 0.726 0.124* 0.061
Thousand kernel weight(g) 1395.160 4806.707** 596.586
Grain yield per plant(g) 1290.933 836.471** 249.423
Grain yield per hectare(kg) 7581467.05 1315159.660** 202674.4
These indicates the presence of higher amount of genetic
variability among inbred lines studied
ANOVA showed
that genotypic mean
squares were
highly significant
(p ≤0.01)
ANOVA showed
that genotypic
mean squares
were significant
(p ≤ 0.05)

27. 4.3 Estimates of Variance Components
Traits δ2g δ2p δ2e PCV GCV
DT 21.89 25.28 3.39 4.86 4.52
DS 32.65 35.66 3.01 5.63 5.39
PH 250.93 307.74 56.81 12.08 10.91
EH 157.46 206.93 49.47 21.38 18.65
NLPP 1.26 1.52 0.26 8.55 7.80
LL 42.36 50.15 7.79 10.44 9.60
LW 0.49 0.73 0.24 8.92 7.26
NTB 11.72 13.59 1.87 24.92 23.14
EL 3.25 4.43 1.18 18.17 15.55
ED 0.06 0.22 0.16 12.15 6.46
NKRPE 0.63 1.10 0.47 8.60 6.47
NKPR 14.55 22.24 7.69 20.57 16.64
NEPP 0.02 0.08 0.06 23.84 12.03
TKW 1403.37 1999.96 596.59 19.54 16.37
GYPP 195.68 445.11 249.43 27.95 18.53
GYPH 370828.42 573502.82 202674.40 35.43 28.49
AGBYPP 7596.89 23792.07 16195.18 23.44 13.25
HI 15.97 27.96 11.99 21.20 16.02
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The magnitude of PCV were slightly > GCV
for all the traits
These indicates influence of environment in the expression
of these traitssufficient genetic variability was observed in most of the traitsGCV showed a wide range of variation
from 4.52 - 28.49 % for the different
traits studied
PCV showed a wide range of
variation 4.86 - 35.43 % for
the different traits studied
The highest GCV and PCV were observed in
indicates the presence of ample variation for these traits
suggest that the selection can be effective for these traits
The lowest GCV and PCV were found in:
showed that variability among the genotypes
was very low for these traits.Moderate GCV
and
High PCV

28. 4. 4 Heritability and Genetic Advance
Traits H2 GA GA %
DT 86.56 3.29 3.17
DS 91.57 3.27 3.09
PH 81.54 12.66 8.72
EH 76.09 11.03 16.38
NLPP 83.10 0.87 6.02
LL 84.46 4.86 7.16
LW 66.27 0.68 7.07
NTB 86.22 2.43 16.43
EL 73.28 1.64 14.18
ED 28.25 0.23 5.99
NKRE 56.69 0.81 6.61
NKPR 65.45 3.74 16.31
NEPP 25.45 0.13 10.79
TKW 70.17 35.31 15.42
GYPP 43.96 14.30 18.95
GYPH 64.66 599.66 28.05
AGBMYPP 31.93 83.71 12.72
HI 57.11 4.07 16.33
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High magnitude of broad sense
heritability
indicate that the variation
observed was mainly under
genetic control and less influenced
by environment for these traits
possibility of effective selection
for genetic improvement of these
traits.
low heritability was observed
Selection for trait will not be effective
The highest genetic
advance was observed
depicts additive gene
effects
high heritability combined
with relatively high genetic
advance
 Indicates phenotypic
selection for these traits will
be effective.
Low Genetic Advance
Selection will not be
effective for these traits

29. 4.5.1 Phenotypic and genotypic correlations of grain yield with
yield related traits
Traits Correlation Coefficient
and significance level
grainyieldperplant
1.GYPP rp=0.698**,rg=0.787**
2.AGBYPP rp=0.761**, rg=0.748**
3.HI rp=0.473**,rg=0.582**
4.NKPR rp=0.386**, rg=0.462*
5.NEPP rp=0.438**, rg=0.435*)
1.EL rp=0.314**
2.LL rp=0.321*
3.LW rp=0.284*
4.NTB rp=0.280*
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showed highly (p ≤ 0.01) +ve Correlation with GYPP
at both genotypic and phenotypic level
Showed highly (p ≤ 0.01) at genotypic level and
(p ≤ 0.05) phenotypic level with GYPPHighly (p ≤ 0.01) +ve Correlation with GYPP
at phenotypic level
showed (p ≤ 0.05) +ve correlation with GYPP
at phenotypic level
simultaneous selection for these traits
might bring an improvement in yield
per plant

30. 4.6 Path Analysis of Grain Yield and Other Traits at
phenotypic level
Traits LL LW NTB EL NKPR NEPP GYPH AGBYPP HI rp
LL -0.0410 -0.0144 0.0004 -0.0824 -0.0051 -0.0173 0.0005 -0.0991 0.0199 0.321**
LW -0.0037 -0.1580 0.0004 -0.0729 -0.0058 -0.0197 0.0006 -0.1125 0.0226 0.284*
NTB -0.0037 -0.0126 0.0050 -0.0719 -0.0021 -0.0073 0.0020 -0.0419 0.0084 0.280*
EL -0.0041 -0.0141 0.0004 -0.8180 -0.0092 -0.0313 0.0010 -0.1793 0.0360 0.314**
1.NKPR -0.0051 -0.0173 0.0005 -0.0991 1.0570 -0.0096 0.0242 0.2567 0.0199 0.386**
NEPP -0.0058 -0.0197 0.0006 -0.1125 0.1787 -0.0570 0.0275 0.2913 0.0226 0.438**
GYPH -0.0092 -0.0313 0.0010 -0.1793 0.2848 -0.0174 0.0900 0.4642 0.0360 0.698**
2AGBYPP -0.0100 -0.0341 0.0011 -0.1955 0.3105 -0.0190 0.0478 0.8740 0.0392 0.761**
HI -0.0062 -0.0212 0.0007 -0.1215 0.1930 -0.0118 0.0297 0.3146 0.1090 0.473**

31. 4.6 Path Analysis of Grain Yield and Other Traits
at genotypic level
Traits NKPR NEPP GYPH AGBY PP HI rg
1.NKPR 0.8250 0.0257 -0.0422 0.2606 0.0820 0.4620*
NEPP 0.1658 0.1280 -0.0397 0.2453 0.0772 0.4350*
GYPH 0.3000 0.0438 -0.1160 0.4439 0.1397 0.7870**
2.AGBPP 0.2851 0.0416 -0.0683 0.7540 0.1328 0.7480**
3. HI 0.2218 0.0324 -0.0531 0.3282 0.3050 0.5820**
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could be used as selection criteria
to improve maize grain yield

32. 5 SUMMARY AND CONCLUSSIONS
 The ANOVA showed that genotypic mean squares were significant for all traits
indicating presence of higher amount of genetic variability among inbred lines
studied.
 The highest GCV and PCV were observed in GYPH followed by NTB. These
estimates suggest that the selection can be effective for these traits.
 High magnitude of broad sense heritability was estimated in DS , DS, NTB,
LL, NLPP, PH, EH, EL, TKW, LW, NKPR and GYPH.
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33. 5 SUMMARY AND CONCLUSSIONS …
 The phenotypic and genotypic correlation analysis revealed that,:
 GYPP had highly significant (p≤ 0.01) positive correlation with :
GYPH, AGBYPP, and HI at both phenotypic and genotypic level , respectively.
 GYPP had highly significant (p≤ 0.01) at phenotypic level but significant
(p≤ 0.05) positive correlation at genotypic level respectively with both
NKPR and NEPP
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34. 5 SUMMARY AND CONCLUSSIONS …
 GYPP had highly significant (p≤ 0.01) positive correlation with EL but
significant (p≤ 0.05) positive correlation with LW, LL and NTB at phenotypic
level.
 Therefore, simultaneous selection for these traits might bring an improvement in
GYPP.
 The result of path coefficient analysis, at phenotypic and genotypic level showed
that traits such as NKPR, AGBYPP, and HI exhibited positive direct effect on
the GYPP.
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35. 5 SUMMARY AND CONCLUSSIONS …
 These traits could be used as selection criteria to improve maize grain yield.
 Inbred lines AMH169-55 and AMH169-86 were found to be superior in terms
of grain yield as well as in other important yield components.
 It is, therefore, suggested that these lines could be used for further
improvement of the maize crop for improved grain yield
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36. Some picture while supervision & collecting data
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37. THANK YOU !!!
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