Interrelations among resistance to bacterial blight, fusarium wilt and seed and seedling characters in cotton

Three strains of cotton were used to study interrelations among resistance to bacterial blight, Fusarium wilt and seed and seedling characters. Averages and frequency distributions of parents and generations were used to determine adequacy of inheritance patterns. Step-up regression analyses were made among sets of thirteen measurements to determine interrelations. Race 14 of X. malvacearum was more virulent than races 1 and 12. SPHI was resistant to races 1 and 12; 801 to races 1, 12 and 14; Brazos was susceptible to the three races. Crosses involving 801 and Brazos indicated that minor genes are present in Brazos. The Genotypes B (subscript 4) B (subscript 4) b (subscript 6m) b (subscript 6m) b (subscript Sm) b (subscript Sm), B (subscript 4), B (subscript 4) b (subscript 6m) b (subscript 6m) B (subscript Sm) B (subscript Sm), b (subscript 4) b (subscript 4), B (subscript 6m), B (subscript 6m) b (subscript Sm) b (subscript Sm) for SPHI, 801 and Brazos respectively were tentatively suggested. Effective resistance to bacterial blight resulted from major and minor gene combinations. Increased resistance to race 1 caused a simultaneous increase in resistance to races 12 and 14. Linear positive correlations between Fusarium wilt foliar and vascular discoloration grades were demonstrated. Vascular discoloration grades were more effective for evaluating Fusarium wilt resistance...