07-08-2013, 01:10 PM
Screening of improved rice genotypes and their hybrids against rice blast (Pyricularia oryzae) under foot hills of North Western Himalayas
ABSTRACT
Rice blast is a serious disease in most of rice growing areas in India particularly when high dose of nitrogen is applied and relative humidity is more. In order to know the reaction of popular high yielding varieties, F1’s and F1’s to rice blast were screened in a uniform blast nursery. Nine diverse genotypes of rice HPR 1164, HPR 2047, China 988, VL91-1754, VL93-3613, VL93-6052, IR578793-08, VL Dhan 221 and JD 8 which were crossed in a diallel mating design (excluding reciprocals). Among the parents, one was susceptible (China 988), one resistant (IR57893-08), one was highly resistant (VL Dhan 221) and remaining six were moderately resistant to leaf blast. Out of thirty six hybrids, six were highly resistant and remaining were moderately resistant to leaf blast and neck blast in both the generations. Cross combinations HPR 2047 x VL93-6052, HPR 2047 x IR 57893-08, China 988 x VLDhan221, China 988 x JD8 and VLDhan221 x JD 8 exhibited resistance against neck blast in F1’s and F2 s’. Therefore, these cross combinations could be utilized for development of hybrids and in breeding programmes.