EVALUATION OF PARENTS AND INTER SPECIFIC HYBRIDS OF COTTON

Abstract

An investigation was carried out at the Plant Breeding Research Field under the Department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh. The experiment was laid out in the Randomized Complete Block Design (RCBD) with three replications to evaluate yield and yield contributing characters of the genotypes under two species in respect to different morphological characters. A total number of eight cotton lines were used for the experiment. Mean performance and divergence analyze were done on yield contributing characters viz. vegetative branches plant -1,node number of first fruiting branches plant -1 . primary fruiting branches plant secondary fruiting branches plant -1,days to (50%) flowering ,days to (50%) boll splitting, bolls plant-1, un-burst bolls plant-1,single boll weight (g), plant height at harvest and seed cotton yield (g plant-1).The mean performances of 11 characters revealed significant variation for each of studied characters in 6 genotypes of cotton. The genotype GB1 exhibited maximum mean value for., primary fruiting branches plant-1, secondary fruiting branches plant-1, days to 50% flowering, days to (50%) boll splitting and un-burst bolls plant-1 and seed cotton yield (g plant-1); similarly genotype GH3 showed highest mean value for vegetative branches plant-1, baolls plant-1 and plant height at harvest and GH1 for node number of first fruiting branches plant -1. The characters under study were polygenitically controlled, hence the expression of the characters were influenced by genotype and environments. The PCV for particular character was higher than corresponding GCV but the difference between GCV and PCV was minimum and approximately equal GCV and PCV was measured for days to (50%) flowering ,days to (50%) boll splitting, plant height at harvest, days to (50%) boll splitting, seeds boll-1 and seed cotton yield (g plant1 )therefore theses characters were less affected by environmental fluctuations. High heritability coupled with moderate genetic advance was estimated against days to boll splitting (h2 b=96.78% and GA=11.21), bolls plant-1 (h2 b=76.44% and GA=14.19), plant height (h2 b=93.51% and GA=16.39) and seed cotton yield (h2 b=96.84% and GA=19.02). Therefore, theses three characters might exploit to improve seed cotton yield through selection and discriminant function analysis. GCA effects for GH3 and GB2 attained significant positive values for all the traits except vegetative branches plant -1 and unburst bolls plant-1 therefore had proved to be the best general combiner for the character. Among the 15 crosses evaluated, the crosses viz.,GH2×GH3, GH3×GB2 and GB2×GB3 recorded significant negative SCA effects for vegetative branches plant -1 and un-burst bolls plant-1 which are desirable for this trait while the crosses recorded significant positive SCA effects for all other traits. The crosses showing high SCA effects with at least one good general combiner as parent could produce desirable transgressive segregants may be studied through diallel selective mating or any other form of recurrent selection.