Use of deletion stocks to identify chromosome regions and evaluation of winter wheats for Karnal bunt resistance

Karnal bunt of wheat caused by Tilletia indica Mitra is a disease of global importance. Resistance breeding is the main option for combating the disease in endemic areas. Evaluation of deletion stocks provides direct evidence of the chromosome regions linked with resistance. Such stocks for all the chromosomes in the background of ‘Chinese spring’ were evaluated against Karnal bunt under artificial inoculation conditions. The stocks showing deletions on‘’ 1AS‘’, ‘ 2AS‘’, ‘ 3AS‘’, ‘ 6AS‘’, ‘ 4AL‘’, ‘ 4BS‘’, ‘ 6BS‘’, ‘ 6BL‘’, ‘ 7BL’, ‘ 1DS‘’, ‘ 1DL‘’, and ‘ 6DS‘’ have shown very high disease during the last 3 years of evaluation (2005–06 to 2007–08) as compared to ‘Chinese spring’ indicating their association with Karnal bunt resistance. From another set of 792 winter wheat lines, seven lines (NI98414/WESLEY, OGALLALA/TX92D7960//BIG DAWG/TX 92U2317, 700-2, 701-14, 703-9, U5237 (2)-16 and U5240 (1)-19) showed less than 1% Karnal bunt infection. These winter wheat lines are promising donor stocks for developing high yielding Karnal bunt resistant wheats for commercial exploitation.