Pre-breeding in sugarcane (Saccharum sp. hybrids) for red rot resistance and economic traits

The present investigation is concerned with the development of genetic stocks for resistance to red rot disease caused by Colletotrichum falcatum Went and other important economic traits. This was studied with progenies obtained from 39 crosses involving 45 parental clones of interspecific and intervarietal origin. The progenies were subjected for screening against red rot under controlled condition testing (CCT) method. The pattern of inheritance of red rot resistance showed in general that, crosses involving resistant parents tend to have more number of resistant progenies than from crosses involving susceptible parents. Out of 39 crosses investigated for race specific resistance as a qualitative trait, 18 crosses showed a simple Mendelian segregation of monogenic nature. Parent progeny regression analysis suggested that about 50% of the variation in the population could be attributed to additive genetic variance (horizontal resistance). Two crosses involving susceptible parents viz., 971235 (S) x Co 1148 (S) and Co 88028 (S) x Co 775 (S) contributed 28-30% resistant progenies. These transgressive segregants are likely to be stable in their resistance due to additive genetic action and could be used as donor parents in red rot resistance breeding programmes for imparting race non-specific resistance. The present investigation has also identified some specific cross combinations for yield, quality and red rot resistance for further exploitation in breeding programme.