VARIATION FOR RESISTANCE TO BACTERIAL-BLIGHT AMONG DIFFERENT HYBRID POOLS OF COTTON IN NIGERIA

Seventy-four cotton (Gossypium hirsutum L.) cultivars, thirty-seven ad vanced breeding lines/varieties and thirty-seven progenies, representi ng six hybrid pools or families developed for the cotton varietal impr ovement programme in Nigera were screened in the field for resistance to bacterial blight, using three isolates of Xanthomonas campestris pv . malvacearum (Smith) Dye. With the exception of Samaru 71, Samaru 72, Samaru 77, ASA (79) 46, ASA (79) 27, ASA (79) 18 and YQ (79) 8 all th e advanced lines/varieties were resistant. The lines RSA (79) 5 and YQ (19) 42 consistantly gave immune and/or hypersensitive reactions. Res istant progenies were obtained within the RASA, RSA, ACSA and ASA hybr id pools; however, the RASA and ASA progenies recorded the highest and lowest frequencies of resistant and susceptible plants, respectively. The range of resistance/susceptibility manifested by these and other breeding materials need to be tested against the array of virulence ge nes that has been shown to exist in the pathogen population in the cot ton growing zones of Nigeria.