Vol. 10, Issue 9 (2021)

Author(s):
Savankumar N Patel, VP Patel, KG Modha, VB Parekh and Ritesh Patel

Abstract:
The extent of genetic variability present in any base population is most important for the success of breeding programme. The present investigation was assessed using 100 F₂ individuals and their parents (NVSR 2179 and NVSR 2803) for characters viz., days to flowering, plant height, panicle length, productive tillers per plant, number of grains per panicle, grain yield per plant, straw yield per plant and harvest index. High estimates of genotypic and phenotypic variance were observed for days to flowering, plant height, grains per panicle, grain yield per plant, straw yield per plant and harvest index. High genotypic and phenotypic coefficient of variation was found in grains per panicle, grain yield per plant, straw yield per plant. Less difference between values of GCV and PCV observed for all the traits suggesting negligible role of environment in the expression of traits, therefore, improvement by phenotypic selection is possible. The characters days to flowering, grains per panicle, grain weight, grain length, grain breadth, L: B ratio, grain yield per plant and straw yield per plant exhibited very high heritability estimates while, plant height and panicle length exhibited high heritability estimates. High heritability coupled with high genetic advance (per cent) for traits plant height, grains per panicle, grain weight, grain yield per plant and straw yield per plant indicated that these characters were governed by additive gene action, selection for improvement of such traits could be rewarding. The green revolution and the breeding of hybrid rice cultivars have significantly improved rice yield by utilization of semi-dwarf genes. Along with variability study molecular dissection was also carried out to detect presence of variation for dwarfing gene sd1 at DNA level between dwarf line NVSR 2179 and tall line NVSR 2803. Total 8 SNPs were identified having good quality score between exon3 of NVSR 2179 and NVSR 2803. The phylogenetic analysis using exon3 sequences of both lines and 25 NCBI blast sequences generated total five clusters. The allelic differences found in form of 8 SNPs may be validated in rice germplasm or populations showing variation for plant height.