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