GENETIC DIVERSITY BASED ON PHYSIOLOGICAL, QUANTITATIVE AND QUALITY CHARACTERS IN RICE GENOTYPES (Oryza sativa L.)
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Date
2011
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ACHARYA N. G. RANGA AGRICULTURAL UNIVERSITY
Abstract
The present investigation was carried out during kharif 2009 at
Agricultural College Farm, Bapatla with 35 genotypes of rice (Oryza sativa L.)
to elicit information on the nature and extent of variability, heritability, genetic
advance, character association, the magnitude of direct and indirect effects of
yield components on yield and genetic divergence based on 18 characters viz.,
plant height (cm), days to 50% flowering, absolute growth rate (AGR), No. of
ear bearing tillers /m 2, panicle length (cm), No. of filled grains /panicle, test
weight (g), grain yield (kg/plot), harvest index (%), grain length (mm), grain
breadth (mm), kernel length (mm), kernel breadth (mm), volume expansion
ratio on cooking, head rice recovery, milling (%), hulling (%) and protein
content of the grain (%).
High PCV, high GCV and high heritability coupled with high GA
observed for No. of filled grains/ panicle, grain yield (kg/plot), harvest
index (%) and absolute growth rate at 50-65 DAT and 65-80 DAT
indicating the presence of wider variability for these traits in the
genotypes studied.
Correlation study indicated positive significant association of days to
50% flowering, panicle length (cm), No. of filled grains/panicle, test
weight (g), harvest index (%) and kernel breadth (mm) at both genotypic
and phenotypic levels while hulling (%) showed the positive significant
association at genotypic level with grain yield. So, improvement in grain
yield is possible by taking above characters in selection scheme as
simultaneous improvement of these characters is possible.
Based on the results of path analysis, it could be concluded that selection
based on characters like days to 50% flowering, panicle length (cm), test
weight (g) and kernel length (mm) with positive correlation with yield
and positive direct effect on yield would result in yield improvement
i.e., profuse tillering plants with large panicles, more grain weight and
grain size might result in higher yield in the genotypes of rice. Quality
characters like grain length (mm), volume expansion ratio on cooking
and protein content of grain might be improved independent of the yield.
The results of D2 analysis indicated the presence of considerable genetic
divergence among 35 genotypes studied. The genotypes were grouped
into six clusters. Clustering pattern of genotypes did not follow
geographical origin, suggesting that geographical isolation might not be
the only factor causing genetic diversity. Based on divergence studies,
crosses might be made between the genotypes of cluster IV viz., IR 8
and VI (MTU 1061) followed by clusters V (CSR 4) and VI (MTU
1061) and clusters IV viz., IR 8 and V viz., CSR 4 to isolate superior
recombinants in segregating populations.
The
principal
component
analysis
identified
seven
principal
components. Out of which, PC1 contributed maximum to the variance.
Divergent genotypes like MTU 1001, MTU 1002, NLR 28523, MTU
1010 and MTU 7029 and the genotypes PR106, ACC .No. 10948, NLR
33358, BPT 2270 and KAVYA could be easily identified through 2D
and 3D plot for utilization in breeding programme.
Hierarchical cluster analysis revealed the sub-groups in the major group
of genotypes through Ward’s minimum variance dendrogram.
Description
Keywords
grain, developmental stages, genotypes, yields, rice, planting, genetics, phenotypes, biological development, harvesting, RICE, Oryza sativa L.