GENETIC ANALYSIS OF HERITABLE TRAITS IN SUNFLOWER (Helianthus anmus L.)

The objective of this study was to determine good combiners, magnitude of heterosis and mode of inheritance for eleven heritable traits in sunflower. For this purpose, a study was conducted on a 8x8 diallel set of sunflower including reciprocals to find out the extent of combining ability, heterosis and nature of gene action for parameters like of days to 50% flowering, plant height, stem thickness, leaf area, head area, days to maturity, achene yield per plant, achene number per plant, 100-achene weight, achene yield (kg/ha) and oil content. The General combining ability (GVA), Specific combining Ability (SCA) and Reciprocal effects (RE) were significant for all the parameters. The SCA effects were of greater magnitude than of GCA effects, which showed high contribution of non-additive gene effects. The GCA:SCA ratio also revealed predominance of non-additive gene effect. Among the inbred lines TF-1, RAI, TF-4 and TF-335 were the best general combiners for all the trait studied. The best combiners for yield were ARI and GUL. Not a single cross combination showed a constant promising result of these heritable traits, however, the cross combinations including TF-1, TF-4, TF-335, ARI, PESH exhibited better performance in nearly all parameters. Positive heterosis for all the characters except for days to 50% flowering and days to maturity was observed. Reciprocal crosses illustrated high potential than direct crosses for most of the characters. Both additive and non-additive variances were involved in the control of all the plant traits. Additive and non-additive equally contributed for days to maturity and achene number per plant. Earliness in flowering, achene yield per plant, achene number per plant and 100-achene weight were under partially dominance controlled. Over-dominance also shoed controlling the inheritance for plant height, stem thickness, head area, days to maturity, achene yield per plant and oil conten