Studies on gene action and combining ability for yield and its component traits in aromatic and red rices (Oryza sativa L.).
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Date
2019-07-04
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CSK HPKV, Palampur
Abstract
The present investigation entitled “Studies on gene action and combining ability for yield and its component traits in aromatic and red rices (Oryza sativa L.)” was conducted at Rice and Wheat Research Center, Malan (Kangra), Himachal Pradesh, during Kharif 2018.
Thirty basmati and red rice genotypes were evaluated in RBD in three replications. Analysis of variance revealed significant differences among the genotypes for all the traits and inferred the presence of huge genetic variability for all the traits studied. Among yield contributing traits, high heritability coupled with high genetic advance and high PCV and GCV was observed for spikelets per panicle, grains per panicle and harvest index which indicated that there is substantial variability ensuring ample scope for improvement of these traits through selection. Mean performance revealed that among basmati genotypes RP 4594-36-26-39-16-22-8-7-3, Vallabh Basmati-24 and RP 4594-55-49-76-42-53-20-15-8 and among the red rice genotypes Deval and HPR2800-1 were the best for yield and other yield contributing traits which may be used for the future rice breeding programme.
The correlation coefficient analysis revealed that grain yield per plant had significant positive correlation with panicle length, spikelets / panicle, grains /panicle, spikelet fertility and harvest index at both phenotypic and genotypic level while plant height had significantly positive correlation with grain yield / plant at only genotypic level. Path analysis revealed that the harvest index had maximum positive direct effect on grain yield/plant at both phenotypic and genotypic levels, respectively suggesting the importance of this trait towards grain yield / plant.
Diversity analysis studies indicated genotypes were grouped into 3 clusters and maximum genetic diversity was observed under clusters II and III followed by I and III, I and II. Grains / panicle contributed maximum towards divergence followed by days to 50% flowering, 1000 seed weight, protein percent and spikelets/panicle Remaining traits had very little or no contribution towards genetic divergence and hence were of little importance.
In experiment II, 10 lines were crossed with two testers. 20 F1's along with parents were analysed. Analysis of variance for the experimental design with respect to total genotypes revealed significant differences among all the yield and yield contributing traits, phenological and grain quality traits. Analysis of variance for line × tester mating design with respect to parents revealed significant differences among lines for all the traits studied. Analysis of variance for combining ability revealed that significant differences were among lines, testers and crosses for most of the traits. The ratio of σ2GCA / σ2SCA of less than unity indicated that the gene effect was predominantly non-additive type for all the characters.
On the basis of SCA effects, top cross combinations for earliness were Pusa Basmati 1121 × HPR 2720, Super Basmati × HPR 2795, Kasturi × HPR 2795, HPR 2800-2 × HPR 2795 and Lakha Mandal × HPR 2720. These combinations also showed resistance to leaf blast and neck blast. HPR 2590 × HPR 2795 (29.15 g/plant) and HPR 2800-2 × HPR 2795 (24.35 g/ plant) were found to be the promising heterotic combinations for yield and related traits as they showed heterosis of 103.63% and 69.75% respectively, in comparison to the check Kasturi.
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