Identification of bacterial leaf blight resistance genes in wild rice of eastern India

Authors: ANIL KUMAR SINGH, EKTA DHARMRAJ, ROHINI NAYAK, PAWAN KUMAR SINGH, NAGENDRA KUMAR SINGH

Abstract: An experiment was conducted during the 2013 monsoon season to screen 35 wild rice accessions against the BX043 strain of Xanthomonas oryzae pv. Oryzae and identify the presence of bacterial blight resistance genes Xa21, xa13, xa5, Xa4, and Xa2. Among the accessions the area under the disease progress curve ranged from 174.88 (NKSWR-65) to 680.54 (NKSWR-34) compared with resistant controls RP bio-226 (93.92), CRMAS 2231-37 (097.28), CRMAS 2232-71 (098.58), and Tetep (178.62) and susceptible control PB-1 (1065.56). On the basis of disease severity 11 accessions showed moderate resistance, 21 were moderately susceptible, and 3 accessions showed susceptible response to the BX043 strain of Xanthomonas oryzae pv. Oryzae, while none of the accessions were found to be resistant. The genetic frequency of the 5 resistance genes varied from 00.00% to 45.71%. The accession NKSWR-25 harbored 3 resistance genes, xa5, Xa4, and Xa2, while accessions NKSWR-16, NKSWR-32, NKSWR-36, NKSWR-41, NKSWR-42, NKSWR-53, NKSWR-64, NKSWR-97, and NKSWR-99 each possessed 2 resistance genes of those 3 (xa5, Xa4, and Xa2). Therefore, these accessions could be used for the transfer of specific bacterial leaf blight resistance genes into well-adapted high-yielding rice cultivars.

Keywords: Bacterial leaf blight, disease severity, SSR markers, resistance, wild rice

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