HETEROSIS MANIFESTATION LEADING TO HYBRID DEVELOPMENT IN UPLAND COTTON

Abstract

Considerable interest exists among cotton breeders in the expression of heterosis within intraspecific Gossypium hirsutum L. or Gossypium barbadense L. or interspecific between both species. Positive heterosis generally exhibits vigor, uniformity and additional yield and yield components of crops. A study of 8 X 8 diallel cross in upland cotton was conducted during 2009 to see the heterotic effects of F₁ hybrids. Eight inbred strains of upland cotton were crossed in 2008, to obtain superior hand-produced hybrids to be utilized in cotton cultivar development program with the objective of producing broad based genetic material. Twenty eight F₁ hybrids   were grown along with their eight parents in randomized complete block design with four replications in an experimental field. The hybrids Malmal X LA-G18 (161.44%), NIAB-78 X LA-G18 (135.76%) and Sindh-1 X Acala-63-74 (123.60%) were obtained with high heterotic effects for seed cotton yield over better parents. The highest heterobeltiosis was displayed by the hybrids Malmal X LA-G18 (123.82%), Malmal X Acala-63-74 (104.39%), and Sadori X Sindh-1 (99.52%). It is recommended that these hybrids may be incorporated in cotton variety maximization program as a tool to improve the cotton yield. The traits studied were mostly expressed over dominant inheritance pattern in F₁ diallel.