Diallel analysis of resistance to aphid in sorghum.
A diallel analysis of plant damage classes and foliar infestation percentage by aphids was conducted under field conditions using 5 varieties exposed to Rhopalosiphum maidis, Melanaphis sacchari, Tetraneura hirsuta [T. nigriabdominalis], T. radicicola and Sitobion miscanthi. Dominance was towards resistance. Additive and dominance variance were significant for both traits, with the additive component being larger than the dominance component. Homogeneity and scaling tests of foliar infestation percentage suggested that complementary non-allelic gene interaction was involved. By using the method of excluding arrays, the results also suggested that complementary interaction might occur between 129-3A and Tx403. Significant variation due to the effects of GCA and SCA was present, suggesting that breeding for aphid resistance should be possible. Lines 2R (P1257595) and 129-3A had the largest negative GCA estimates.