Abstract:
The present experiment was conducted at Sugarcane Breeding Institute (ICAR), Coimbatore
to generate diverse genetic stocks for resistance to red rot disease caused by Colletotrichum
falcatum Went. and other important economic traits. This study was carried out with
progenies obtained from 39 crosses involving 45 parental clones of interspecific and
intervarietal origin. The interspecific origin involves diverse forms of Saccharum officinarum
and S. spontaneum that are hitherto unutilized in the breeding programme. The progenies
were evaluated for resistance to red rot disease and economic traits such as cane yield and
quality. 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 in addition to red rot resistance
for further exploitation in breeding programme.
