Preeti S V
Diallel Analysis in Rice Bean - Vellayani Department of Plant Breeding and Genetics, College of Agriculture 1999
A diallel analysis in ricebean (Vigna umbellata (Thunb.) Ohwi and
Ohashi) was carried out in the Department of Plant Breeding and Genetics, during
1997 - '98. The experimental material consisted of six parental lines and 30 F I
hybrids, laid out in Randomised Block Design with three replications. The six
parents were 3 LG, 5 LG, 6 LG, 8 LG, 9 LG, and 100 LG obtained from the germ
plasm collection maintained at NBPGR, Thrissur. The observations were recorded
on yield and yield attributing characters.
Significant differences were detected among the mean performance of
the genotypes, for all the characters studied. The combining ability analysis
carried out by Method I, Model I of Griffing's approach (1956), revealed that the
parent, 8LG was the best general combiner for most of the yield attributing traits.
Among the crosses, 8LG x 3 LG exhibited outstanding sea for seed yield per plant.
The crosses involving 8 LG were found to be good specific combiners. The
combinations involving 3 LG and 6 LG also gave good specific combining ability
effects.
The numerical analysis by Hayman's approach indicated overdominance
for almost all characters, which was confirmed by graphical analysis. The
dominance of decreasing alleles in the parents was indicated by the negative value
of F for all characters except, plant height, length of pods and number of seeds per
pod. An almost equal distribution of genes with positive and negative effects was
indicated by the ratio of H2 to 4H} for all the characters. The regression coefficient
of covarince between parents and their offsprings in each array (Wr) on variance
of all progenies in each parental array (Vr) did not- differ from unity, for plant
height, length of pods, seed yield, 100 seed weight, days to maturity and protein
content, indicating that assumption of non-allelic interaction was satisfactory for
these characters. The Vr - Wr graph indicated that the parents were genetically
divergent for days to first flowering, number of pods per plant, number of seeds
per pod, 100 seed weight, days to maturity, root weight and nodule weight.
Manifestation of heterosis was seen for all the characters studied.
Among the hybrids, 8 LG x 3 LG was the most outstanding for yield and yield
related characters. The crosses, 8 LG x 9 LG, 8 LG x 100 LG, 6 LG x 9 LG, 100 LG
x 8 LG and 6 LG x 3 LG also performed better in yield and yield attributing
characters. In general, hybrids involving 8 LG and 6 LG were found to be
heterotic.
630.28 / PRE/DL
Diallel Analysis in Rice Bean - Vellayani Department of Plant Breeding and Genetics, College of Agriculture 1999
A diallel analysis in ricebean (Vigna umbellata (Thunb.) Ohwi and
Ohashi) was carried out in the Department of Plant Breeding and Genetics, during
1997 - '98. The experimental material consisted of six parental lines and 30 F I
hybrids, laid out in Randomised Block Design with three replications. The six
parents were 3 LG, 5 LG, 6 LG, 8 LG, 9 LG, and 100 LG obtained from the germ
plasm collection maintained at NBPGR, Thrissur. The observations were recorded
on yield and yield attributing characters.
Significant differences were detected among the mean performance of
the genotypes, for all the characters studied. The combining ability analysis
carried out by Method I, Model I of Griffing's approach (1956), revealed that the
parent, 8LG was the best general combiner for most of the yield attributing traits.
Among the crosses, 8LG x 3 LG exhibited outstanding sea for seed yield per plant.
The crosses involving 8 LG were found to be good specific combiners. The
combinations involving 3 LG and 6 LG also gave good specific combining ability
effects.
The numerical analysis by Hayman's approach indicated overdominance
for almost all characters, which was confirmed by graphical analysis. The
dominance of decreasing alleles in the parents was indicated by the negative value
of F for all characters except, plant height, length of pods and number of seeds per
pod. An almost equal distribution of genes with positive and negative effects was
indicated by the ratio of H2 to 4H} for all the characters. The regression coefficient
of covarince between parents and their offsprings in each array (Wr) on variance
of all progenies in each parental array (Vr) did not- differ from unity, for plant
height, length of pods, seed yield, 100 seed weight, days to maturity and protein
content, indicating that assumption of non-allelic interaction was satisfactory for
these characters. The Vr - Wr graph indicated that the parents were genetically
divergent for days to first flowering, number of pods per plant, number of seeds
per pod, 100 seed weight, days to maturity, root weight and nodule weight.
Manifestation of heterosis was seen for all the characters studied.
Among the hybrids, 8 LG x 3 LG was the most outstanding for yield and yield
related characters. The crosses, 8 LG x 9 LG, 8 LG x 100 LG, 6 LG x 9 LG, 100 LG
x 8 LG and 6 LG x 3 LG also performed better in yield and yield attributing
characters. In general, hybrids involving 8 LG and 6 LG were found to be
heterotic.
630.28 / PRE/DL