IJIIIIJ
4.5 Genetic diversity
4.5.8 Contribution of characters towards divergence of the genotypes
The values of Vector I and Vector II are presented in Table (14). Vector T obtained from PCA expressed that days of first flowering (0.1271), plant height (cm) (0.0266), number of branches per plant (0.1633), number of cluster per plant (0.1658), fruits per cluster (0.3804) and fruit length (cm) (0.85 14) were major characters that contribute to the genetic divergence. It was the reflection of first axis of differentiation. In vector H days of first flowering (0.6760), plant height (cm) (0.0735), number of branches per plant (1.2380), fruits per cluster (0.1152) and fruit yield per plant (g) (0.0074) showed their important role toward genetic divergence.
The value of Vector 1 and Vector 11 revealed that both Vectors had positive values for days of first flowering, plant height (cm), number of branches per plant and fruits per cluster indicating the highest contribution of these traits towards the divergence among 30 genotypes of tomato. Negative values in both vectors for days 50%
flowering, fruits per plant and fruit weight (g) had lower contribution towards the divergence.
Table 12. Cluster mean values of 10 different characters of 30 genotypes
Characters I LI III IV
Days of first flowering 53.6 53.7 54.2 53.5
Days 50% flowering 64.0 64.1 64.2 64.7
Plant height (cm) 76.1 70.7 81.8 81.6
Branches per plant 8.3 8.9 8.7 10.1
Number of cluster per plant 11.6 14.2 I 12.9 16.4
Fruits per cluster 3.8 3.3 5.2 3.3
Fruits per plant 44.6 49.2 55,2 58.0
Fruit weight (g) 45.2 17.9 10.8 20.7
Fruit length (cm) 4.0 3.5 2.9 3.4
Fruit yield per plant (kg) 1819.1 862.0 531.8 1228.4
Table 13. Eigen values and yield percent contribution of 10 characters of 30 germplasm
Characters Eigen values Percent variation Cumulative % of Percent va nation
Days of first flowering 3.551 35.51 35.51
Days 50% flowering 2.112 21.12 56.63
Plant height (cm) 1.670 16.70 73.33
Branches per plant 1.118 11.18 84.51
Number of cluster per plant 0.814 8.14 92.65
Fruits per cluster 0.364 3.64 96.29
Fruits per plant 0.166 1.66 97.95
Fruit weight (g) 0.135 1.35 99.30
Fruit length (cm) 0.054 0.54 99.84
Fruit yield per plant (kg) 0.017 0.16 100.00
U Elgen values U Percent variation
40 35 30 25 20
is
10 S 0
k
"4'
0 AQ"
t
C,
e
I ¼<&
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Fig. 7. Comparison between Eigen values and yield percent contribution of 10
characters of 30 germplasm
Table 14. Relative contributions of the ten characters of 30 varieties to the total divergence
Characters Vector-i Vector-2
I)ays of first flowering 0.1271
I
0.6760Days 50% flowering -0.2360
-
0.0266
-0.1746
Plant height (cm) 0.0735
Branches per plant 0.1633 1.2380 I
Number of cluster per plant 0.1658 -0.2805
Fruits per cluster 0.3804 0.1152
Fruits per plant -0.0610 -0.0829
Fruit weight (g) -0.0089 -0.2 158
Fruit length (cm) 0.8514 -2.6570
Fruit yield per plant (kg) -0.0095 0.0074
4.5.9 Selection of genotypes as parent for hybridization programme.
Among the inter cluster distance, distance between I and III (11.995) were the highest, distance between I and other cluster were higher and other clusters were more or less intermediate distance. Intermediate diverse parents have the more chance to contribute heterosis in the subsequent generations. To select cluster to obtain more heterotie genotype four pairs of clusters to be considered for this purpose, they are I and 11, 11 and 111. III and IV. IV and I.
Cluster IV had the highest cluster mean for days to 50% flowering, number of branches per plant, number of cluster per plant and Fruits per plant but average to below average for days to first flowering, Plant height (cm). Fruits per cluster, Fruit weight (g) and Fruit length (cm) were most important yield contributing character. Again, cluster I had the highest cluster mean for Fruit weight (g), Fruit length (cm) and Fruit yield per plant (g) but average to below average for Plant height (cm). number of branches per plant, number of cluster per plant and Fruits per plant were most important yield contributing character. The cluster IV comprised with the genotype of BD-7270. 1313-7276, BD-7278, BD-7281. BD-7295. BD-7762 and cluster I comprised with the genotype of 1313-7260.
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BARI Tomato-3. BARI Tomato4, BARI Tomato-7, BARI Tomato-9, BAR! Tomato-l4, IUSA Rubi.
Hybridization between the genotypes of cluster I and cluster IV will manifest maximum heterosis and create wide genetic variability. Genetically distant parents are usually able to produce higher heterosis. Considering magnitude of genetic distance, contribution of diflèrcnt characters towards the total divergence, magnitude of cluster means for different characters and field performance the genotypes 024, G27 G29 from cluster I and 04 04 04 from cluster IV would be suitable for highest yield per plant for future hybridization programme.
It assumed that highest heterosis would be manifest in cross combination involving the genotypes belonging to divergent clusters. However for a practical plant breeder, the objective was not only high heterosis but also to achieve high level of production.
4.6 Future line of work
The amount of variability present was of wide range for all the characters studied hence attention needs to be given for these traits during selection for improvement of fruit yield.
The present investigation on path analysis revealed that, fruit weight and fruit length had the highest positive effect on fruit yield at both gcnotypic and phenotypic levels. Hence, importance has to be given for these characters in future breeding programme to improve yield in tomato
From the association analysis. it is evident that both number of fruits per plant as well as number of branches per plant can improve yield. Therefore, recurrent selection programme aimed in this direction may yield fruitful results
Genetic diversity is largely contributed by days to 50% flowering, number of fruits per cluster and fruit yield per plant. Thus, these characters may be given high emphasis while selecting the lines for hybridization programme to generate large
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variability and it will provide immense scope for improvement of yield through selection.
5. Lines identified for higher fruit yield viz., BARE Tomato-3, BARE Tomato4, BARE Tomato-i, BARE Tomato-9 and BAR! Tomato-14, may be further tested over location and years to know their stability.
ftibracy)
2
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