GENETIC DIVERSITY FOR PHYSIOLOGICAL AND PRODUCTIVITY TRAITS IN DROUGHT TOLERANT GROUNDNUT GENOTYPES
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Date
2015
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Acharya N.G. Ranga Agricultural University
Abstract
The present investigation entitled “Genetic diversity for physiological and productivity traits in
drought tolerant groundnut genotypes” was carried out with 50 genotypes to study their diversity, in
addition to variability, heritability, genetic advance, character associations and path effects for
productivity and physiological traits with a view to identify potential and genetically diverse
genotypes along with suitable selection criteria for higher kernel yield in drought tolerant groundnut.
The experiment was conducted during kharif’ 2014 in a randomized block design with three
replications at the College Farm, Agricultural College, Mahanandi, Kurnool District, Andhra Pradesh
and data was recorded on yield, yield components and physiological traits.
The results revealed highly significant differences among the genotypes for all characters
studied, indicating the existence of sufficient variation among the genotypes studied. The per se
performance revealed higher number of pods per plant, filled pods per plant and kernels per plant in
addition to lower days to maturity, plant height and SLA for spanish bunch genotypes, while virgina
genotypes had recorded higher sound mature kernel per cent, 100 kernel weight, shelling per cent,
SCMR, pod, haulm and kernel yields per plant. Among the spanish bunch genotypes, those with
ICRISAT origin had recorded higher average for pods per plant, filled pods per plant, kernels per
plant, SCMR and haulm yield per plant, while the genotype with Tirupathi origin had recorded higher
sound mature kernel per cent and 100 kernel weight, in addition to lower days to maturity, plant
height and SLA. However, genotypes with Kadiri origin had recorded higher average for pod yield
per plant, shelling per cent and kernel yield per plant. In general, K1725 had recorded maximum and
significantly higher pod, haulm and kernel yields per plant, compared to other genotypes studied in
the present investigation, indicating its potential as an important parent in hybridization programmes
aimed at improvement of these traits. Further, it was also observed to be on par with the best
genotype for shelling per cent and SCMR.
Quantitative assessment of genetic divergence resulted in grouping of the genotypes into nine
clusters. Among these, cluster I consisted of maximum genotypes (26), while cluster III had nine
genotypes; cluster IV had seven genotypes; cluster VIII had three genotypes. The clusters II, V, VI,
VII and IX were monogenotypic and consisted of single genotype. The mode of distribution of
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genotypes from different geographical regions into various clusters was at random indicating that
geographic diversity and genetic diversity are not related. Classification of the genotypes in each
cluster based on habit group also revealed the distribution of genotypes to be at random indicating
that habit group and genetic diversity were also not related.
An analysis of the inter and intra-cluster distances revealed maximum inter-cluster distance
between clusters VI and VIII followed by I and VIII indicating that genotypes from these clusters
were highly divergent meriting their consideration in selection of parents for hybridization. Further,
intra-cluster distance was observed to be maximum for cluster VIII, while it was zero for the
monogenotypic clusters, II, V, VI, VII and IX as they included only single genotype.
A perusal of the results on cluster means revealed high pods per plant, filled pods per plant,
kernels per plant, pod yield per plant, kernel yield per plant and haulm yield per plant for cluster, IX.
However, 100 kernel weight was more for cluster VIII. In contrast, high SMK and early maturity was
noticed for cluster VII; low plant height and high shelling per cent was observed for cluster V; and
high SCMR in addition to low and desirable SLA was recorded for cluster VI, indicating the
importance of selection of genotypes from the corresponding clusters in hybridization programmes
for effecting improvement of the respective traits. Further, 100 kernel weight was observed to
contribute maximum, followed by haulm yield per plant towards the total divergence.
An analysis of the results on variability, heritability and genetic advance revealed high GCV,
PCV, heritability and genetic advance as per cent mean for 100 kernel weight, pod yield per plant,
haulm yield per plant and kernel yield per plant indicating scope for improvement of these traits
through selection.
A perusal of the results on character associations revealed positive and significant association
of kernel yield with days to maturity, pods per plant, 100 kernel weight, pod yield per plant, shelling
per cent, SCMR and haulm yield per plant was observed in the present investigation, indicating an
increase in kernel yield with an increase in these characters. Further, significant and negative
associations were noticed for kernel yield per plant with plant height. A perusal of the results on
inter-character associations revealed significant and positive association of days to maturity with
plant height, pods per plant; pods per plant with filled pods per plant, kernels per plant, sound mature
kernels per cent, pod yield per plant and haulm yield per plant; filled pods per plant with kernels per
plant, sound mature kernels per cent and pod yield per plant; kernels per plant with pod yield per
plant; 100 kernel weight with pod yield per plant and SCMR, in the present investigation, indicating a
scope for simultaneous improvement of these traits through selection. In contrast, significant and
negative association of plant height with SCMR; kernels per plant with 100 kernel weight; sound
mature kernels per cent with specific leaf area; pod yield per plant with shelling per cent and SCMR;
and shelling(%) with SCMR were observed in the present study, indicating the need for balanced
selection while effecting simultaneous improvement for these traits.
A perusal of the results on path coefficients revealed high residual effect for both phenotypic
and genotypic path coefficients, respectively, indicating that other attributes besides the characters
studied are contributing for kernel yield. The results also revealed days to maturity, pods per plant,
100 kernel weight, pod yield per plant, shelling per cent and haulm yield as important selection
criteria for kernel yield improvement in drought tolerant groundnut.
K 1725, K 1719, K 1717, K1718 and K 1848 have been identified in the present investigation
as potential genotypes for kernel yield per plant and majority of other characters studied.
Hybridization of K 1725, K 1719, K 1717 and K 1718 genotypes belonging to Cluster III with K
1848 of Cluster I is expected to result in transgressive segregants with high yield and desirable yield
component characters. Studies on variability, heritability, character associations and path coefficients
also revealed 100 kernel weight, pod and haulm yields per plant to be effective selection criteria for
kernel yield improvement in drought tolerant groundnut.
Description
D5370
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