000			03666nam a22002057a 4500
003			OSt
005			20220103120505.0
008			130805b xxu||||| |||| 00| 0 eng d
040			_cCPGS
082			_a633.18233
100			_a Loukham Varun Singh _9966
245			_aDivergence studies and path analysis of yield contributing traits in lowland rice (Oryza sativa L.) / _cby Loukham Varun Singh
260			_aUmiam : _bCPGS, CAU _cc2012
300			_a[24], 67p.: _bill., some col.;
440			_a[Genetics and Plant Breeding, School of Crop Improvement] _9967
520			_aRice (Oryza sativa L) is one of the most important cereal crops of the world which has a wide range of genetic diversity and selection of diverse parents for hybridization program is an important factor for getting superior recombinants (heterosis) and transgressive segregants. Rice grain yield is influenced by several traits. Therefore, selection for yield directly may not be much rewarding unless yield components are taken into consideration. Path analysis provides a good measure of the association between characters and helps to identify the most important character(s) to be considered for effective selection for increasing yield. Twenty-one lowland rice genotypes of the North East India were planted in RBO in 2 different environments, one with application of organic manure and the other with synthetic chemical fertilization, with 2 replications each. Oata on 12 _yield contributing traits were recorded. According to the metroglyph index score and the scattered diagram, the 21 genotypes were clustered into 7 groups. LR 23 (Sahabhagi Dhan), LR 29 (Boro Paddy), LR 30 (Lal Manohar) had the minimum index score, and LR 15 (Priya) had the maximum index score. A dendogram was created based on Mahalanobis 02 distance matrix. LR 18 grouped separately from rest of the genotypes. The others 20 genotypes were clustered into two groups; group 1 consisted of nine genotypes , whereas group 2 consisted of eleven genotypes. Among the genotypes, LR 25 and LR 26 in group 1 showed the minimum divergence of 13.17. The maximum divergence was observed between LR 18 (Paijong) and LR 28 (269.91). Combining the results obtained through metroglyph analysis and Mahalanobis 02 statistics, top 10 genotypes with high index score and 02 distance was identified (LR 1 X LR 18, LR 5 X LR 18, LR 7 X LR 18, LR 13 X LR 18, LR 15 X LR 18, LR 16 X LR 18, LR 18 X LR 20, LR 18 X LR 24, LR 18 X LR 25, and LR 13 X LR 25) which had the chance of producing superior recombinant in the segregating generation. Partitioning of correlation coefficients of eleven yield contributing traits with grain yield into direct and indirect effects revealed that biological yield (0.772) in organic environment and harvest index (0.6463) in chemical fertilizer environment had the maximum direct effect towards grain yield. The two fertilization regimes revealed opposite path coefficient effect for panicle length while path coefficient of days to 50% flowering, plant height, panicles per plant, grains per panicle, 100 grains weight, biological yield and harvest indexshowed similar positive effect in both the different fertilization regime. Path coefficients of tillers per plant, spikelets per panicle and percent spikelet fertility showed negative effect in boththe environments. The data generated in this study would help make decisions in the lowland rice breeding programme, pertaining to selection of diverse parents and segregating progenies with respect to yield contributing traits.
650			_aLowland rice _xGenetic analysis _9968
700			_aRai, Mayank _eMajor Advisor _9969
942			_2ddc _cTH
999			_c4082 _d4082