Combining Ability for Grain Yield and other Agronomic Characters in Rice

Abstract

A diallel analysis to identify parental lines and specific crosses through combining ability estimation was undertaken in a set of seven rice varieties. Griffing's Method I, Model I was employed for this purpose. The seven parents and 42 F1s (including reciprocals) were grown in a randomized block design with four replications. Data were collected on 16 characters including a few root characters for which requisite number of plants were grown (in RBD design) in pot culture. GCA and SCA variances were significant for all the characters. Reciprocal effects were also significant except for rachilla/panicle and grain length. An early flowering NC 1281 Mutant and Taichung Native 1: bold grain mutant were good general combiners for majority of characters. The crosses with high specific combining ability generally involved high × low general combiners. The cross Nira × T‐N‐1: bold grain mutant recorded best SCA effects for grain yield as well as all the important yield attributes and also for major root characters. In fact, in most of the high SCA registering crosses for various characters, Taichung Native 1: bold grain mutant or Nira was one of the parents commonly involved.