Plant Disease Research

One hundred sixty three entries from national Screening nursery-1 (nSn-1), 540 entries from national Screening nursery-2 (nSn-2) and 912 entries from rice germplasm (land races) were evaluated against the prevalent pathotypes viz. PbXo-1 and PbXo-7 and emerging pathotypes PbXo-9 and PbXo-10 of the bacterial blight pathogen in Punjab, India under artificial inoculation conditions. Two years data revealed that thirteen entries from nSn-1, 40 entries from nSn-2 and three land races viz. Acc. no. 441, 784 and 867 were found resistant to all the four pathotypes. The evaluation data of all the tested entries (1615) suggested that 163 (10.1%) and 151 (9.3%) of the entries were resistant to established pathotypes PbXo-1 and PbXo-7, respectively as compared to 60 (3.9%) entries were resistant to emerging pathotype PbXo-9. Most of the entries which were resistant to PbXo9 also showed resistance to all the other three pathotypes. Similarly, only 4.5% (73) entries showed resistant/moderately resistant reaction to PbXo-10 which was found to be virulent on newly identified gene Xa38. These resistant entries can either be released as new varieties or further utilized as donors in multiple disease resistance breeding programmes.