studies on genetic variability

1. ‫الرحيم‬ ‫الرحمن‬ ‫ال‬ ‫بسم‬
A Study on Genetic Variability, Interrelationships among some
Agronomic Traits and Path Coefficient Analysis in Pearl Millet
‫اللؤلؤي‬ ‫الدخن‬ ‫في‬ ‫المسار‬ ‫معامل‬ ‫وتحليل‬ ‫الحقلية‬ ‫الصفات‬ ‫بعض‬ ‫ارتباط‬ ،‫الوراثي‬ ‫التباين‬ ‫دراسة‬
By
Omar Abdalla Bakhit Hassan
M.Sc. presentation
Supervisor
Dr. El hag Hassan Abuelgasim
23 February 2010

2. INTRODUCTION
 Pearl millet (Pennisetum glaucum (L.)R.Br) or "Dukhun", is a cereal crop
belonging to section Panacea of the family Poaceae.
 Pearl millet is a robust, diploid species (2n=14), cross-pollinated grass with
immense genetic diversity.
 The center of origin for pearl millet stretching from Western Sudan to
Senegal.

3.  It's planted across a wide range of It's environments around the
world.
 grown as a subsistence grain and forage crop for livestock. Also its
stalk can be used as building material or as fuel.
 Pearl millet comes as the sixth among cereal crops in the world in
terms of production, coming after wheat, rice, maize, barley and
sorghum.

4. PEARL MILLET WORLD’S PRODUCTION AND
PRODUCTIVITY:
 The world total grown area, in 2006 was 36.297 million hectares.
 produced 32.074 million metrics tones.
 The world average grain yield was ranged from and 883.6 kg/ha for
the year 2006.

5. PEARL MILLET IN SUDAN:
 Is a preferred food crop for the majority of the inhabitants of
Western Sudan.
 In terms of both area and production it ranks second after sorghum.
 The crop is almost exclusively raised under rain-fed conditions with
97% of the total area in the country being raised under traditional
farming conditions.
 About 95% of the crop area is found in Western Sudan (Kordofan
and Darfur states) mainly in the extensive sandy soil zone.
 The annual average rainfall in the millet growing areas varies from
200 mm to 750 mm, falling during a short rainy season of 2 to 4
months.

6. PEARL MILLET IN SUDAN (Cont):
 The annual average rainfall in the millet growing areas varies from
200 mm to 750 mm, falling during a short rainy season of 2 to 4
months.
 The crop was grown on 2.256 million hectares producing 0.792
million metric tones in 2006 (FAO, 2007).
 The average yield of grain per hectare in Sudan was 351 Kg/ha, in
2006.

7. CONSTRAINTS OF PRODUCTION:
 The low and unreliable rainfall comes first since 99% of the area
cultivated depends on rainfall.
 The poor genetic stocks cultivated by farmers
 Pests and diseases cause serious damage to the crop.
 The poor cultural practices followed by farmers.
 Lack of agricultural services and inputs.
 Lack of financing and extension services.

8. OBJECTIVES OF THIS STUDY:
 To obtain information on genetic variability of agronomic traits in
local and exotic pearl millet genotypes.
 To study the genotypic and phenotypic interrelationships between
the different pairs of various agronomic traits.
 To study the path coefficient analysis of some important
agronomic traits and their direct and indirect effects on grain yield.

9. MATERIALS AND METHODOLOGY:
[1] Materials:
 Sites: El shegaila, Beinu and El jekka in rain fed areas (North
Kordofan state), and Shambat was planted under irrigation area in
(Khartoum state).
 Genotypes: The 18 local and exotic genotypes were tested.
 Design: Randomized complete block design (RCBD) with four
replications was used.
 The experimental plot: consisted of 4 rows of 5 meter length, with a
spacing of 75 cm between rows and 50 cm between plant holes. Six
to eight seeds were sown in each hole.
 Recommended agronomic practices were used.

10. Table 1: The pearl millet genotypes used in the study of genetic
variability and interrelationships among different traits
No Genotype Origin Note source
1 Ashana ICRISAT Released ARC-Sudan
2 Ugandi Uganda Released ARC-Sudan
3 Dembe (Um shegaira) Kordofan Collection ARC-Sudan
4 Aish burno West Africa Collection ARC-Sudan
5 Um gerfa Kordofan Collection ARC-Sudan
6 GB 87-35 ICRISAT promising ARC-Sudan
7 Bauda Darfur Collection ARC-Sudan
8 Demde yellow Kordofan Collection ARC-Sudan
9 Dahabaya ARC promising ARC-Sudan
10 Local Kordofani Kordofan Collection ARC-Sudan
11 Sudan II ICRISAT promising ARC-Sudan
12 HSD 2254 Darfur Collection ARC-Sudan
13 HSD 2260 Darfur Collection ARC-Sudan
14 HSD 2261 Darfur Collection ARC-Sudan
15 HSD 2279 Darfur Collection ARC-Sudan
16 HSD 2348 Kordofan Collection ARC-Sudan
17 HSD 2380 Kordofan Collection ARC-Sudan
18 HSD 2416 Kordofan Collection ARC-Sudan

11. [2] Data collection:
 All measurements were taken from the two central rows in each plot.
 The 17 agronomic traits were measured which includes :
 plant population/ hectare.
 Days to 50% to flowering.
 days to 95% maturity.
 plant height (cm).
 stem diameter (cm).
 productive tillers/ plant.
 panicle length (cm).
 panicle width (cm).

12. [2] Data collection (Cont):
 number of panicles/ plot.
 dry panicles/ plot.
 number of seeds/ panicle.
 1000 seed weight (g).
 grain yield/ plant (g).
 grain yield/ hectare (kg).
 biological yield/ hectare (kg).
 threshing percentage.
 harvest index.

13. [3] Statistical analysis :
 Single site and combined analysis – MSTAT-C software.
 Mean separation (LSD 0.05).
 Phenotypic, genotypic and variation.
 Heritability (Hanson et al. 1956).
 Phenotypic coefficients of variation (Burton 1952).
 Genotypic coefficients of variation (Burton 1952).
 Genetic advance and percentage genetic advance (Johnson et al.
1955).
 Phenotypic and genotypic correlation coefficients (Miller et al. ,
1958) .
 Path coefficients analysis (Dewey and Lu ,1959) .

14. RESULTS
 Analysis of variance revealed highly significant differences among
locations for all traits.
 Highly significant differences among genotypes were observed for
most of the traits studied.
 Significant differences for genotypes x locations interactions were
detected for most of the traits.

15. Table 2: Overall means average for the different characters in 18 pearl millet
genotypes at four sites in 2005/06 season.
SiteCharacter
El shegaila Beinu El jekka Shambat
Grand
mean
Plant population/ha 27842 36408 16008 36209 29130
50% days to flowering 69.98 59.10 75.06 66.07 68.01
95% days to maturity 99.48 89.29 105.07 96.61 97.79
Plant height (cm) 164.75 151.208 142.63 180.83 159.84
Stem diameter (cm) 1.039 0.878 0.992 1.18 1.03
Productive tillers/plant 1.39 1.625 1.751 3.67 2.18
Panicle length (cm) 23.19 24.590 24.849 22.16 24.26
Panicle width (cm) 2.56 2.400 2.403 2.30 2.42
No of panicles/ plot 50.58 66.111 30.910 168.04 79.00
Dry panicles wt. (kg)/plot 1.04 1.208 0.971 3.86 1.801
No of seeds/panicle 1530 1234 1312 1450 1381
1000 seeds weight (g) 8.69 7.07 7.77 8.09 7.93
Grain yield (g)/plant 20.40 14.454 30.09 54.89 30.12
Grain yield (kg)/ha 541.198 529.644 450.554 1546.280 766.919
Biological yield (kg)/ha 3303.174 4223.833 1942.626 8478.773 4486.978
Threshing % 54.76 48.02 55.09 46.12 51.02
Harvest index % 16.21 12.790 23.60 18.32 17.77

16. Table 3: Means for different characters of 18 pearl millet genotypes evaluated at
four sites in 2005/06 season.
Genotype Plant
Population
/ha
Days to
50%
flowering
Days to
95%
maturity
Plant
Height
(cm)
Stem
Diameter
(cm)
Productive
Tillers/plant
Ashana 26934 59.19 86.44 152.92 1.04 2.30
Ugandi 26827 58.25 85.25 156.77 1.17 2.57
Dembe (Um shegaira) 29663 77.31 107.25 163.25 1.12 2.01
Aish burno 28996 71.06 101.50 166.76 0.99 1.98
Um gerfa 27717 73.13 104.12 146.84 0.96 1.88
GB 87-35 28880 59.44 86.81 150.93 1.00 2.17
Bauda 28676 62.50 92.38 149.02 0.91 2.33
Demde yellow 30880 63.25 93.19 155.12 1.08 2.63
Dahabaya 29876 67.19 98.44 163.61 1.01 2.16
Local Kordofani 31049 72.75 103.63 160.37 0.99 2.35
Sudan II 27823 58.81 86.38 171.55 1.00 2.26
HSD 2254 30933 74.00 105.06 180.84 1.00 2.17
HSD 2260 27939 72.44 102.56 173.66 1.11 2.20
HSD 2261 29625 71.44 102.06 167.63 1.07 1.97
HSD 2279 28160 68.94 99.38 148.88 0.96 2.24
HSD 2348 31885 69.06 99.31 153.69 1.03 2.00
HSD 2380 28046 70.81 101.00 155.85 1.03 2.08
HSD 2416 30436 75.00 105.44 159.67 1.03 2.03
Mean 29130 68.01 97.79 159.84 1.03 2.18
SE ± 406** 0.636** 0.665** 1.84** 0.015** 0.055**
C.V% 15.68 9.81 7.84 10.63 11.28 19.71

17. Table 3: Continued ….
Genotype Panicle
Length
(cm)
Panicle
Width
(cm)
No of
Panicle
/plot
Dry panicle
Weight
(kg)/plot
No of seeds
/panicle
1000-seed
Wt.(g)
Ashana 24.20 2.62 75.50 1.567 1299 8.25
Ugandi 25.41 2.44 87.44 1.563 1213 8.59
Dembe (Um shegaira) 23.80 2.59 73.19 1.830 1498 7.16
Aish burno 24.07 2.02 70.69 1.325 996 7.84
Um gerfa 24.60 2.43 63.44 1.656 1430 7.93
GB 87-35 23.68 2.41 78.44 1.580 1265 8.44
Bauda 25.28 2.32 85.47 1.762 1195 7.71
Demde yellow 24.33 2.53 97.25 2.266 1519 8.51
Dahabaya 25.86 2.41 83.94 2.325 1493 8.07
Local Kordofani 23.40 2.49 90.81 1.842 1507 7.91
Sudan II 30.66 2.13 77.63 1.928 1603 7.80
HSD 2254 23.24 1.91 81.56 1.877 1183 8.17
HSD 2260 23.87 2.44 80.67 1.689 1560 7.55
HSD 2261 23.43 2.44 75.88 1.769 1201 8.32
HSD 2279 21.08 2.54 78.25 2.148 1499 7.25
HSD 2348 23.37 2.44 78.75 1.667 1343 7.74
HSD 2380 23.41 2.68 69.06 1.631 1478 7.97
HSD 2416 23.05 2.66 74.56 1.992 1579 7.57
Mean 24.26 2.42 79.00 1.801 1381 7.93
SE ± 0.265** 0.030** 1.519** 0.039** 26** 0.104**
C.V% 9.98 11.87 20.57 17.55 15.80 11.17
LSD (0.05) 1.68 0.19 11.76 0.22 151.30 0.61

18. Table 3: Continued ….
Genotype Grain
Yield (g)/
plant
Grain
Yield(kg)/ha
Biological
Yield(kg)/ha
Threshing
%
Harvest
Index %
Ashana 34.75 835.347 3528.008 57.86 22.05
Ugandi 33.48 782.027 35902.212 58.80 20.44
Dembe (Um shegaira) 29.92 746.480 4140.748 51.04 17.15
Aish burno 23.71 568.747 3847.928 52.34 15.84
Um gerfa 25.74 617.624 3385.82 47.10 16.96
GB 87-35 31.96 768.697 3807.938 58.30 19.58
Bauda 33.40 764.254 3528.008 54.67 19.05
Demde yellow 34.71 958.872 4179.401 53.58 18.44
Dahabaya 36.45 710.045 4345.58 49.50 18.45
Local Kordofani 26.24 694.938 4381.128 45.84 15.40
Sudan II 39.35 905.552 3910.135 55.78 24.30
HSD 2254 25.98 686.051 4336.695 41.98 15.05
HSD 2260 26.84 662.057 4185.620 44.46 15.69
HSD 2261 28.69 692.272 4007.888 48.33 15.53
HSD 2279 28.83 729.596 4221.168 45.83 17.78
HSD 2348 23.01 640.729 4025.660 51.40 15.10
HSD 2380 25.83 614.958 4104.64 48.52 14.89
HSD 2416 32.97 854.009 4274.488 53.37 18.15
Mean 30.12 735.816 4012.330 51.04 17.77
SE ± 1.07** 14.667** 75.333* 0.860** 0.477**
C.V% 23.65 21.47 20.05 12.12 21.81
LSD (0.05) 4.93 3.27 18.79 4.24 2.53

19. Table 4: Means for grain yield (kg)/ha of 18 pearl millet
genotypes evaluated in 2005/06 season.
site
Genotype El shegaila Beinu El jekka Shambat Grand mean
Ashana 529.645 833.125 461.180 1762.226 835.347
Ugandi 457.663 840.679 412.340 1557.833 782.027
Dembe (Um shegaira) 507.429 434.558 520.759 1625.370 746.480
Aish burno 494.099 399.900 380.014 1051.293 568.747
Um gerfa 531.423 419.451 359.910 1239.69 617.624
GB 87-35 532.310 780.248 506.667 1162.376 768.697
Bauda 510.982 432.781 391.012 1816.435 764.254
Demde yellow 481.656 444.332 484.322 2090.144 958.872
Dahabaya 774.916 439.890 321.696 2240.329 710.045
Local Kordofani 668.276 491.433 321.692 1412.98 694.938
Sudan II 572.300 684.272 526.978 1885.751 905.552
HSD 2254 455.886 545.640 446.998 1356.106 686.051
HSD 2260 622.067 566.081 402.566 1151.712 662.057
HSD 2261 505.650 437.225 427.449 1479.63 692.272
HSD 2279 614.069 503.874 399.900 1498.292 729.596
HSD 2348 501.208 423.004 299.481 1359.660 640.729
HSD 2380 486.988 333.250 418.562 1331.223 614.958
HSD 2416 558.083 532.310 490.544 1812.880 854.009
Mean 541.198 529.644 431.002 1546.280 735.816
SE ± 30.666 26.400 31.33 53.333 14.667
C.V% 28.91 27.65 38.31 19.47 21.47
LSD (0.05) 4.12 3.54 3.87 7.18 3.27

20. Table 5: Estimate of phenotypic coefficient of variation (PCV %), Genotypic
coefficient of variation (GCV %), heritability (h²), expected genetic advance
from section (GA) and genetic advance as percentage of mean (GA %) for
agronomic traits in 18 pearl millet genotypes tested at four sites in 2005/06
season.
CHARACTER (PCV %) (GCV %) (h²) (GA) (GA %)
Plant population/ha 17.21 6.62 0.147 1.71 5.24
50% days to flowering 19.32 16.64 0.742 20.03 29.53
95% days to maturity 15.31 13.15 0.738 22.89 23.26
Plant height (cm) 14.97 10.53 0.495 24.40 15.26
Stem diameter (cm) 15.19 10.17 0.448 0.145 14.02
Productive tillers/ plant 25.09 15.53 0.383 0.45 19.79
Panicle length (cm) 17.36 14.21 0.67 5.81 23.95
Panicle width (cm) 20.47 16.68 0.66 0.68 27.99
No of panicles/ plot 28.44 19.64 0.48 23.04 27.93
Dry panicles wt. (kg)/plot 33.52 28.56 0.73 0.89 50.13
No of seeds/panicle 28.49 23.71 0.69 561.73 40.65
1000 seeds weight (g) 14.33 8.97 0.39 0.92 11.57
Grain yield (g)/plant 35.03 25.83 0.54 11.8 39.24
Grain yield kg/ha 38.07 31.44 0.68 0.39 53.47
Biological yield kg ha 23.71 12.59 0.28 0.624 13.78
Threshing % 24.57 21.33 0.75 19.12 38.13
Harvest index % 37.89 30.98 0.67 8.73 52.20

21. Table 6: Phenotypic and genotypic correlation coefficients
between different pairs of traits in 18 pearl millet genotypes
evaluated at four sites in 2005/06 season.
TRAIT DTF DTM PLH SD NPTP PNL PNW NP DPWT NSP TGWT GYP GYH BYH THP HI
DTF 1.006** 0.366 -0.005 -0.69** -0.59** 0.061 -0.426 0.137 0.173 -0.590** -0.573* -0.573* 0.723** -0.89** 0.946**
DTM 0.972** 0.336 -0.078 -0.65** -0.60** 0.045 -0.374 0.173 0.176 -0.527* -0.570* -0.571* 0.74** -0.93** -0.95**
PLH 0.193 0.186 0.258 -0.097 0.233 -0.72** 0.036 0.053 -0.064 -0.084 -0.159 -0.107 0.782** -0.305 -0.199
SD 0.018 -0.059 0.313 0.433 -0.085 0.367 0.416 -0.147 0.116 0.316 0.102 0.177 0.358 0.189 -0.038
NPTP -0.437 0.413 0.060 0.217 0.179 0.065 0.941** 0.188 0.084 0.599** 0.468* 0.614** -0.038 0.399 0.532*
PNL 0.421 -0.429 0.197 0.028 0.093 -0.403 0.113 0.119 0.204 0.075 0.593** 0.522* -0.344 0.515* 0.721**
PNW 0.003 0.006 0.296 0.320 0.103 0.207 -0.014 0. 112 0.564* -0.220 0.226 0.187 -0.087 0.037 -0.047
NP 0.324 0.285 0.157 0.243 0.839** 0.121 0.053 0.308 0.076 0.459 0.392 0.517* 0.133 0.161 0.291
DPWT 0.061 0.097 0.154 0.050 0.176 0.106 0.161 0.295 0.663** -0.318 0.675** 0.574* 0.437 -0.355 -0.025
NSP 0.079 0.072 0.020 0.086 0.027 0.188 0.455 0.036 0.520* -0.445 0.457 0.383 0.512* -0.234 -0.017
TGWT 0.317 0.303 0.098 0.221 0.324 0.137 0.000 0.286 -0.019 0.233 0.036 0.245 -0.507 0.429 0.236
GYP 0.381 0.382 0.017 0.021 0.321 0.352 0.202 0.210 0.596** 0.358 0.093 0.978** -0.197 0.455 0.720**
GYH -0.439 0.425 0.006 0.133 0.375 0.358 0.193 0.407 0.642** 0.368 0.251 0.832** -0.231 0.522* 0.719**
BYH 0.265 0.297 0.489* 0.229 0.139 0.106 0.113 0.255 0.396 0.309 0.023 0.042 0.104 -0.83** -0.68**
THP 0.655** -0.69** -0.157 0.127 0.192 0.385 0.016 0.081 0.291 0.204 0.252 0.363 0.423 0.346 0.893**
HI 0.665** 0.661** 0.117 0.088 0.289 0.491* 0.027 0.166 0.064 0.035 0.158 0.620** 0.632** 0.286 0.736**
The genotypic correlations are the upper triangle and phenotypic correlations in the lower one. *, ** and ns are the level of significance at 5%, 1% and non-significant,
respectively. D.f = n-2=16, r 5%= 0.468, r 1% = 0.590
Legend:
DTF Days to flowering PNL Panicle length (cm) TSWT 1000 grains weight (g) HI Harvest index
DTM Days to maturity PNW Panicle width (cm) GYP Grain yield per plant (g) THP Threshing%
PLH Plant height (cm) NP Number of panicle/ plot GYH Grain yield (kg/ ha)
SD Stem diameter DPW Dry panicle weight kg/ plot BYH Biological yield (kg/ ha)
NSP Number of seeds/ panicle NPTP Productive tillers/ plant

22. Table 7: Path coefficient analysis of the direct and indirect
effect of five yield components and their genotypic
correlation coefficients with grain yield/ plant in pearl millet
genotypes at four sites in 2005/06 season.
Effect on grain yield plant (g)
Indirect effect via
Character Direct
effect
Productive
tillers/plant
Panicle
length
(cm)
Panicle
width
(cm)
Number
of seeds/
panicle
1000
seeds
weight
(g)
Genotypic
correlation
with grain
yield/
plant
Productive
tillers/plant
0.286 0.176 0.065 0.081 0.142 0.464
Panicle length
(cm)
0.510 0.176 -0.403 0.195 0.074 0.593
Panicle width (cm) 0.223 0.065 -0.403 0.537 -0.221 0.226
Number of
seeds/panicle
0.119 0.081 0.195 0.537 -0.461 0.457
1000 seeds weight
(g)
-0.022 0.599 0.074 -0.221 -0.461 0.036
Residual 0.664

23.  The improved varieties generally showed good yield performance
than the local ones for most of the traits studied.
 The performance of the genotypes was greater under irrigated clay
soil conditions (Shambat site).
 The phenotypic coefficients of variation were higher than the
genotypic coefficients of variation for all the traits studied.
CONCULSIONS

24.  Grain yield/ plant and harvest index showed high values for both
genotypic and phenotypic coefficients of variation, this indicates the
importance of these traits in selection for grain yield improvement.
 Very high to moderate heritability estimates were observed for most
of the agronomic traits studied.
 High Heritability coupled with high genetic advance as percentage
of mean were recorded for Grain yield/ hectare, grain yield/plant,
harvest index and dry panicle weight/ plot. These traits can be
useful as selection criteria for yield improvement.

25.  The study revealed that the genotypic correlation coefficients were
generally higher than the corresponding phenotypic ones. This
indicates the presence of genetic variability among genotypes for
the agronomic traits studied.

26.  The results revealed that grain yield/ plant may be the best indicator
in selection for grain yield improvement, as well as harvest index,
dry panicles weight/ plot, panicle length, number of panicles/ plot
and productive tillers/ plant.
 Path coefficient analysis revealed that, among yield components,
panicle length had the highest direct effect on grain yield /plant,
followed by productive tillers/ plant and panicle width.

27. CONTACT: omarbakhit@yahoo.com.
Mobile Phone: 0915085680