Evaluation of some sugarcane genotypes, Saccharum spp. for resistance to the whip smut disease of sugarcane incited by the fungus Ustilago scitaminea Syd.

Philip W. Marchelo, Ahmed O. Ahmed, Khalid A. Bukhari

Abstract


Nine sugarcane genotypes, hybrids of Saccharum spp. viz. B 70531, B 79136, BJ 7451, BJ 7938, BJ 82105, BT 74209, COC 671, DB 75159 and TUC 75-3 were evaluated in a field screening trial with the current three commercial varieties CO 527; CO 997 and CO 6806 incorporated as susceptible (S), resistant (R) and very highly resistant VHR checks, respectively. The experimental materials were artificially inoculated by the teliospores of the smut fungus using the pin-prick (PPM), dipping method (DM), and natural spreader row infection (NIM) methods; using the smut sensitive genotype NCO 376 as spreader rows. The respective mean percent smut infection on clump basis in the plant cane crop was 5.29%, 2.29% and 4.12% for pin-prick, dip and natural infection, respectively. In the first and second ratoons percent infection was 6.8%, 6.7%, 6.6%, and 9.55%, 10.72%, and 10.1%, respectively. Four genotypes BJ 82105, B 70531, DB 75159 and TUC 75-3 were rated as VHR as the resistant checks CO 6806 and CO 997. Three genotypes BT 74209, CO C671, and B 79136 were rated as (HR). Two genotypes BJ 7451 and BJ 7938 were rated S, similar to the susceptible check CO 527. Usually only genotypes with VHR and HR reaction types are considered suitable for further propagation and commercialization.

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