An experiment was performed to analyse the variability parameters and frequency distribution properties in F 2 population of CBMAS 14065 x Mappillai Samba for grain yield and its associated parameters. The estimated genetic parameters showed, slightly higher PCV than GCV reflecting the influence of environment. High GCV, high PCV, high heritability along with high genetic advance as per cent of mean was observed in the number of filled grains per panicle suggests the additive gene action which is important for selection. The parameters like plant height, the number of productive tillers per plant, panicle length, the number of filled grains per panicle and thousand grain weight showed a significant positive correlation with single plant yield. Significant positive skewness were observed for the number of productive tillers and grain L:B ratio which helps in fixing the selection criterias and benefits the improvement of traits in F 2 generation.

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Rice is the dietary staple for more than one third of the world's population and it is a model cereal species serving as the genetic platform to study the functions of the genes. In the present study, twenty four genotypes were studied for the thirteen grain quality traits. Principal Component Analysis was utilized to estimate the relative contribution of various traits for total variability. Four components were found to possess Eigen value more than 1. The PC1, PC2, PC3 and PC4 contributed 27.73, 19.12, 15.27 and 10.12 per cent of variability. Together, they accounted for 72.24 per cent of the variability of the genotypes used in the study has revealed the traits contributing for the variation.

Asses cultiva Centre fo A set of 36 somes have detected w from two to produced m 87.76% poly polymorphi value of 0.45 RM 266, RM similarity co

Rice production system is greatly affected by blast disease caused by Magnaporthe grisea Barr which causes significant yield reduction throughout Asia and different parts of the globe. Developing resistant varieties has been most efficient and economical method for controlling blast disease in rice. Identification of broad spectrum resistance genes against prevailing isolates of the pathogen is a key determining success of developing resistant varieties. However, the blast resistance characterization and evaluation has not been well studied. In the current study, 3 parental lines namely CO 51 (Pi54), 562-4 (a NIL of CO 43 harboring Pi 9) and a susceptible genotype Improved White Ponni (IWP) were evaluated against local isolates of blast pathogen. Presence of Pi9 and Pi54 blast resistance genes in the parental lines was confirmed by using functional markers such as NBS4 and Pi54MAS respectively. All the three genotypes were evaluated against blast disease in a hot spot environment. Both CO51 and 562-4 carrying the Pi54 and Pi9 genes respectively showed moderate resistance against blast disease whereas IWP showed a susceptibility reaction against blast disease. Results indicated that pyramiding of these genes would improve resistance against blast disease. The present study has favored the selection of blast resistant parental lines which can be utilized as donor in breeding programs.

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