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Subject: Plant Breeding × Author: Bairagi, Priyanka × Start date: 2013 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Genetic variability of root traits of different classes of rice (Oryza sativa L.) in Assam
    (AAU, Jorhat, 2020-10) Bairagi, Priyanka; Sharma, K. K.
    Root characters for plant selection have been major breeding objectives for development of stress tolerant varieties in rice. Therefore the present investigation was conducted for comparative study of root traits and some yield attributing traits in different classes of rice (Ahu, Sali, Bao and Hybrid) in Assam. The study revealed presence of genetic variability among the genotypes for all the root and yield attributing traits. Bao varieties showed maximum root development throughout its growth period upto maturity in comparison to the other classes of rice. Highest phenotypic coefficient of variation and genotypic coefficient of variation was observed for the root length, root volume and root: shoot ratio. Heritability in broad sense was found to be high for root length, plant height, root volume and root: shoot ratio. Genetic advance as percentage of mean was found to be maximum for the root: shoot ratio, root volume and root length. High heritability along with high genetic advance as percentage of mean indicates presence of additive gene action and simple selection procedure can be adopted for improvement of yield. Correlation coefficient revealed positive association of fresh root weight, root: shoot ratio, total tillers per plant, effective tillers per plant with grain yield per plant respectively at genotypic level. Higher genotypic correlation coefficient indicates less influence of environmental effects on traits. Genotypic path analysis revealed 1000-grain weight, fresh shoot weight showed highest positive direct effect on grain yield. D2 analysis revealed total 11 numbers of clusters and cluster I and cluster VII showed highest numbers of genotype (5 each). Contribution of traits to total divergence was observed highest for root length followed by root volume and plant height. Inter cluster average distance was found to be maximum between cluster VIII and XI; IV and VIII and intra cluster average distance was found to be maximum for cluster I followed by cluster VII and cluster II. Clustering pattern of the genotypes revealed it did not follow any particular pattern with respect to the origin of the genotypes. Parental lines selected from cluster IV, VIII and XI can be used for hybridization programme.