MSc

Livestock, a major contributor to agriculture sector requires a balanced diet of three
parts of green grass and one part of leguminous fodder. Among all the legumes in Fabaceae
only ten species were domesticated and can be used as fodder. But due to their poor adaptability
to stress, they yield minimum. The wild Vigna species which are chief source for their
remarkable characters of the biotic and abiotic stress resistance are primarily considered to be
utilized for food, fodder and medicine purposes. Studies on the genetic diversity and
biochemical constituents of the wild and domesticated wild relatives of the Vigna species are
necessary to provide useful information to improve the cultivated varieties or to domesticate
the wild ones. It was also reported that in wild Vigna species a very wide range of variability,
both in terms of important agronomic characteristics and genetic diversity exist and can be used
in crop improvement.
Vigna stipulacea (Lam.) Kuntz which is also known as “Minni Payaru” is a
indigenous, traditional underutilized wild legume mostly used for food, fodder and green
manure has the ability to survive harsh environment and resist various biotic and abiotic
stresses.
In this context, the present study entitled “Unraveling the potential of an underutilized
wild legume Vigna stipulacea (Lam.) Kuntz for fodder purpose”, was envisaged to assess its
potential for fodder yield and quality. The study was carried out at Department of Plant
Breeding and Genetics, College of Agriculture, Vellayani, during 2020-2022. Thirty accessions
of Vigna stipulacea collected from NBPGR were assessed in Randomized Block Design (RBD)
with 3 replications during 2020-22. The seeds were scarified using sand paper and sown in
field at a spacing of 30 x 15 cm in a plot size of 3m2
. Plants were harvested at 50 percent
flowering stage. Five randomly selected representative plants were chose to record the data for
characters such as number of primary branches per plant, number of secondary branches per
plant, number of leaves per plant, number of nodes per plant, internodal length, days to 50
percent flowering, green fodder yield per plot, dry fodder yield per plot, leaf dry weight per
plant, stem dry weight per plant, number of seeds per pod, 100 seed weight, seed yield per
plant, plant height, days to maturity, leaf area index leaf stem ratio, crude protein content, crude
fibre content, total phenol content, condensed tannin content and total antioxidant content. The
characters were evaluated by various statistical tools viz., analysis of variance, genotypic
coefficient of variation (GCV), phenotypic coefficient of variation (PCV), heritability, genetic
advance, correlation studies, path analysis, cluster analysis and discriminant function analysis.
Analysis of variance revealed that all the characters except number of primary branches
per plant and number of seeds per pod differed significantly and had considerable variation
among genotypes.
All the characters except plant height exhibited high phenotypic coefficient of variation
(PCV) than genotypic coefficient of variation (GCV) implying the environmental influence on
expression of the characters. Plant height shown equal values of PCV and GCV which implies
that there was no environmental influence on the expression the character. A high range of
GCV and PCV was reported for characters number of secondary branches plant per plant,
number of nodes per plant, internode length (cm), green fodder yield per plot (g), dry fodder
yield per plot (g), leaf dry weight per plant (g), stem dry weight per plant, seed yield per plant
(g), plant height (cm), leaf area index and leaf stem ratio (LSR), as there was high GCV direct
selection of these characters is feasible.
High range of heritability combined with high genetic advance was observed in number
of secondary branches per plant, number of leaves per plant, number of nodes per plant,
internodal length, green fodder yield per plot, dry fodder yield per plot, leaf dry weight per
plant, stem dry weight per plant, seed yield per plant, plant height, leaf area index and leaf stem
ratio. This implies that these characters were controlled by additive gene action where direct
selection is feasible and can be used as good selection criteria for crop improvement in V.
stipulacea to be utilized for fodder purpose.
Degree and direction of association of various quantitative characters which contribute
to yield are represented by correlation studies. In the current investigation green fodder yield
per plot shown a positive significant phenotypic and genotypic correlation with characters such
as number of leaves per plant, number of nodes per plant, internodal length, days to 50 per cent
flowering, dry fodder yield per plot, leaf dry weight per plant, stem dry weight per plant, plant
height, leaf area index and leaf stem ratio.
Based on path analysis, leaf dry weight per plant, number of leaves per plant, internodal
length, days to 50 percent flowering, leaf stem ratio and plant height was found to have positive
direct effect on green fodder yield per plot. Therefore, direct selection of these characters will
be rewarding for genetic improvement of yield.
Cluster analysis reveals extent of genetic diversity existing among germplasm.
Genotypes selected from divergent clusters for hybridization would produce maximum
heterosis All seventeen characters were considered for cluster analysis and genotypes were
grouped into five clusters. Grouping of genotypes revealed that cluster I (17 genotypes) was
the largest cluster followed by cluster II (7 genotypes), cluster III (4 genotypes) and cluster IV
(1 genotype) and cluster V (1 genotype). Highest intra cluster distance was observed for cluster
II and lowest for cluster IV & cluster V. The maximum inter-cluster D2
values among
genotypes was observed between clusters II and V minimum inter -cluster D2
values was
observed between cluster IV and V. Cluster means revealed that cluster V genotypes had
maximum mean values for number of leaves per plant, number of nodes per plant, green fodder
yield per plot, dry fodder yield per plot, leaf dry weight per plant and plant height. Cluster IV
had maximum mean values for number of secondary branches per plant, internodal length,
green fodder yield per plot, stem dry weight per plant, 100 seed weight, seed yield per plant,
plant height. Therefore, genotypes of cluster V and cluster IV can be utilized in breeding
programme to improve green fodder yield of Vigna stipulacea.
Discriminant function analysis aid in discriminating superior genotypes from nonsuperior genotypes by constructing a selection index. In the present study selection index was
constructed including eight characters such as number of leaves per plant, internodal length,
days to 50 percent flowering, leaf dry weight per plant, plant height, leaf stem ratio, crude fibre
and crude protein. The outcomes of discriminant function analysis shows that the genotypes
T5 (IC 550545) was superior in terms of yield and yield attributing characters followed by T1
(IC 331457), T4 (IC 550551), T25 (IC 553510), T27 (IC 550532), T15 (IC 553525), T7 (IC
524667), T29 (IC 550538), T2 (IC 121435), T13 (IC 610275) and least superior genotype was
T18 (IC 331436) followed by T10 (IC 261321). These genotypes of Vigna stipulacea can be
considered for hybridization programme to develop superior varieties of Vigna stipulacea for
fodder purpose.
Crude fibre content was maximum for T9 (IC 622865) (47.5 percent) and minimum for
T10 (IC 261321) (14.5 percent). Highest crude protein content was noted in T5 (IC 550545)
(15.75 percent) and lowest in T16 (IC 521215) (1.75 percent). Highest total phenol content was
noted in T17 (IC 553520) (1.641 percent) and lowest total phenol content was observed in T28
(IC 553538) (0.758 percent). Condensed tannin content was maximum in T8 (IC 553494)
(0.0239 percent) and minimum in T2 (IC 121435) (0.0113 percent). Highest total antioxidant
content was observed in T29 (IC 553538) (386.86 µg of ascorbic acid per mg) and lowest was
observed in T8 (IC 553494) (31.30 µg of ascorbic acid per mg).