GENETIC ANALYSIS OF GRAIN YIELD AND ITS COMPONENTS IN MAIZE

Nature of gene action and genetic parameters for yield and yield components were studied in a diallel cross involving eight inbred lines of maize. The field experiments were conducted at National Agriculture Research Centre, Islamabad during 2005. The data regarding grain yield and yield relating attributes were recorded from replicated experiment of F1 hybrids including direct and reciprocal crosses, and the self’s. The adequacy of genetic model was determined through regression coefficient and covariance – variance (Wr-Vr )test to validate the data set. The data were analysed according to Hayman’s analysis of variance and components of genetic variation were estimated for all the characters under study. Additive genetic effects appeared to be more pronounced in the genetic control of grain yield plant-1, ear length, rows ear-1, grains row-1 and 100-grain weight. The parental lines are supposed to contained equal number of dominant and recessive genes for all the traits except for number of rows per ear, for which the genes were distributed asymmetrically among the parents. The graphic analysis revealed over dominance type of gene action for all the characters studied.