Diallel Analyses of Yield and Other Agronomic Characters in Gossypium hirsutum L.1

Abstract

SummaryHayman's diallel cross analysis was employed to investigate the nature of the actions and interactions of genes involved in the inheritance of yield, its components, and other agronomic characters in Upland cotton (Gossypium hirsutum L.). Nine selected varieties, all possible F1 hybrid combinations among these varieties, and their corresponding F2's were grown in a split‐plot design with four replications.Heterosis was measured as the departure of the F1 from the average midparent value, and inbreeding depression was measured as the reduction of F2 below F1 performance. Both heterosis and inbreeding depression effects were small but significantly different from zero for all 11 characters studied.Weight of lint per seed and number of nodes met all the assumptions required for the diallel analysis. However, overall epistasis was found in plant height, earliness, boll size, and number of bolls per plant. multiple allelism and possibly correlated gene distribution appeared to be present in days to first flower, seed index, lint percent, number of seeds per boll, and yield.The diallel analysis revealed that all the characters were polygenetically inherited and exhibited partial dominance. The results also showed that heterosis was due to dominance or epistatic gene action, or both.