Combining Ability in Upland Cotton—Ginning and Fibre Characters

An 8 × 8 diallel analysis of combining ability was conducted to characterise the genetic architecture of the population and to isolate best parents for hybridization aiming to improve ginning and fibre properties in Upland cotton (Gossypium hirsutum). The variances due to general and specific combining ability, both, were significant for all the six characters, (G.O.T., seed index, lint index, fibre length, fibre strength and fibre fineness) studied. The magnitude of general combining ability variances was, however, about four to six times higher than those due to specific combining ability. A breeding plan which may mop up the additive gene effects effectively and can maintain certain degree of heterozygosity in cotton has been suggested for maximum exploitation. The Punjab strain A102 was the best general combiner for four of six characters (seed index, lint index, fibre length and fibre fineness). The per se performance of the parents had high relationship with their general combining ability effects. The genetic and geographic diversity of the parents had high association with their specific combining ability