Combining ability for components of resistance to early leaf spot and yield of inter- and intraspecific peanut lines*

Seven interspecific peanut lines and the cultivar «Southern Runner» were crossed in a half-diallel, i.e. without reciprocals. F 1 plants were selfed and F 2 progenies evaluated for early leaf spot reaction and yield. The purpose of the study was to ascertain from F 1 and F 2 populations, crosses which were most likely to give the greatest expression of early leaf spot resistance and yield. Field early leaf spot assessment was made using the Florida leaf spot rating scale and determinations were made for lesion diameter, amount of sporulation, and latent period in both the field and laboratory. Genetic analysis was performed using the Griffing method 2 model 1. Significant differences existed among crosses for visual leaf spot rating, latent period, and amount of sporulation in the F 2 generation (P = 0.05). Pod yield, based on individual plants, differed significantly (P = 0.05) among the F 2 progenies but not in the F 1 . Little heterosis was found among the F 1 hybrids. Performance in the F 1 was not reflected in the performance of the F 2 as rank correlation between the two populations for pod yield was low (r = 0.32) and not significant (P = 0.05). Combining ability effects (both general and specific) were significant for yield and disease parameters in the F 2 generation