Earliness component analysis through diallel cross method

Inheritance and interrelationships of morphological and phenological components of earliness were evaluated in a diallel analysis involving five early-maturing parents and a standard cultivar. This study was initiated in 2003 by making all possible crosses, without reciprocals, among the six parents. Field evaluation of the six parental genotypes and the 15 Fl was made in 2004 in a randomized complete block design with four replications. Of 13 earliness components studied, all but days to first square, vertical flowering interval, boll maturation period, and production rate index showed significant additive genetic variance. Heritability estimates ranged from 0.08 for production rate index to 0.45 for days to first open boll. Correlation analysis showed generally that the lower the node to the first fruiting branch and the shorter the plant, the earlier was the onset of squaring, flowering, and boll opening.