TY  - BOOK
AU  - Asoontha
AU  - Mareen Abraham (Guide)
TI  - Genetic variability for yield and resistance to legume pod borer, Maruca vitrata (Fab.) in yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) verdcourt)
U1  - 630.28 
PY  - 2017///
CY  - Vellayani
PB  - Department of Plant Breeding and Genetics, College of Agriculture
KW  - Plant Breeding and Genetics
N1  - MSc
N2  - The present study entitled “Genetic variability for yield and resistance to legume pod borer, Maruca vitrata (Fab.) in yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt)” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2016-2017, with the objective to evaluate yard long bean germplasm for yield and legume pod borer resistance as well as identification of promising genotypes.
	The study involved two separate field experiments.  In the first experiment thirty genotypes, collected from different locations waere evaluated in a Randomized Block Design (RBD) with three replications for legume pod borer resistance.  The following damage parameters viz., per cent of infested flower buds, number of larvae per 25 flowers and per cent infestation of pods were recorded at flower bud initiation, flowering and pod formation stages of the crop respectively.  Non glandular trichome density on pod wall (counts mm-2) was also recorded at the vegetable maturity stage to assess the morphological basis of resistance.  Plant resistance index was worked out using metroglyph analysis and twelve genotypes showing moderate resistance to legume pod borer was identified. They were subjected to yield evaluation in the second field experiment.
	The twelve moderately resistant genotypes were evaluated in a Randomized Block Design (RBD) with three replications and the following observations viz., days to 50 per cent flowering, days to first harvest, pod yield plant -1 (g), pods plant-1, length of pod (cm), weight of pod (g), seeds pod-1, 100 seed weight (g), length of harvest period (days), crop duration (days) were recorded. Analysis of variance was calculated for all the characters under study. The highest mean yield of 485.03 g was recorded in case of Puthuppady local and lowest mean yield of 176.97 g was observed in case of IC 39945.  Highest mean pod weight was recorded for Githika and minimum for Wayand local.  Pod yield plant-1 exhibited the highest PCV (34.58%) and GCV (29.9%).
High heritability coupled with high genetic advance was observed for pod yield plant-1, pods plant-1, length of pod and weight of pod.  Significant positive correlation with yield was observed for all characters except days to 50 per cent flowering.  Path coefficient analysis revealed that yield was directly and positively correlated with seeds pod-1, crop duration, number of pods plant-1 and 100 seed weight.
The genetic divergence was studied using Mahanalobis D2 statistics and the genotypes were grouped into five clusters. Cluster V showed the highest cluster mean for the characters viz., pod yield plant-1, length of pod, weight of pods and seeds pod-1. It also showed the lowest cluster mean for days to 50 per cent flowering and days to first harvest. The inter cluster distance was maximum between cluster I and cluster II and least between cluster I and cluster IV. Intracluster distance was highest for cluster III followed by cluster II.  Cluster IV and cluster V were the solitary ones.  Selection index was also calculated to discriminate the desirable genotypes and it was observed that Puthuppady local, Githika and IC 39947 recorded high values of selection index.
 The results from the study revealed that the genotypes Puthuppady local, Githika a released variety from KAU and IC 39947 were superior for yield and resistance to legume pod borer.  Hence Puthuppady local and IC 39947 can be considered for further crop improvement programmes for developing high yielding legume pod borer resistant varieties

UR  - http://krishikosh.egranth.ac.in/handle/1/5810139928
ER  -