Genetic divergence in elite genotypes of Indian mustard (Brassica juncea L. Czern & coss.)
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Date
2012
Authors
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Publisher
CCSHAU
Abstract
An attempt was made to study the genetic divergence amongst 90 advance genotypes of
Indian mustard. Significant difference for various traits indicated substantial amount of variability
existed among the genotypes for various traits. High heritability coupled with high genetic advance was
observed for seed yield and most of the traits. Based on relative magnitude of genetic distances 90
genotypes were grouped into 9 clusters. The clusters I comprising 20 genotypes followed by cluster II
consosting of 18 genotypes, cluster III with 15 genotypes, cluster IV, V, VI, VII, VIII and IX contained
10,8,7,7,3 & 2 genotypes, respectively. No correspondence was observed between the geographical and
the genetic diversity, but distribution of genotypes were random and independent.The magnitude of
inter-cluster distance was greater than intra-cluster diatances, suggesting presence of diversity among
the clusters. The maximum inter-cluster distance was observed between cluster VIII and IX (9.756)
followed by II and IX (9.619), cluster IV and IX (9.120) and cluster III and IX (9.094). The use of
genotypes in hybridization from these clusters having most of the desirable characters are likely to
produce more transgressive segregants. The D
2
analysis further indicated that high variation for various
seed yield contributing traits viz. number of secondary branches per plant, number of primary branches
per plant, siliquae on main shoot, siliqua angle, 1000 seed weight and main shoot length contributed
more than 68 % of the total divergence and had maximum contribution towards genetic divergence. In
general genotypic correlation coefficient were higher in magnitude than their phenotypic correlation
coefficient. Seed yield per plant was found to be positively and significantly correlated with number of
primary branches per plant, number of secondary branches/plant, primary branch angle, main shoot
length, siliqua length and number of seeds per siliqua. Path analysis confirmed that characters such as
main shoot length, number of primary branches/plant, number of secondary branches/plant, number of
seeds per siliqua and siliqua length were the major component traits of seed yield and hence these
characters should be given priority in selection in view of their high heritability coupled with high
genetic advance also. The genotypes RH-8812, RH-0950, RH-9304, RH-0784, RH-0905, RH-0871,
EC-597328, RH(OE)-0903, RH-0835, RH-0847, RH(OE)-0801, RH-0910, RH-0912, RH-0825, RH-0848, RH-0850 selected from various divergent clustetrs having most of the desirable characters were
identified as promising on the basis of genetic divergence and per se performance for several traits
particularly for seed yield and oil content and can be used in future breeding programme for improving
seed yield and component traits in order to enhance overall productivity of Indian mustard.
Description
Keywords
Sowing, Developmental stages, Planting, Yields, Genetics, Genotypes, Mustard, Biological phenomena, Genetic processes, Selection