Family selection is widely used in early stages of selection in sugarcane breeding programs. Families are evaluated in the first one or two stages of selection and individual clones are selected from within superior families. These selected clones are evaluated for their performance in two or three selection stages before commercial release of superior clones. This study was undertaken to assess the relative performance of five sugarcane families for predicting potential parental combinations and also to identify rare and elite recombinants that can be exploited in future. Results from this study highlighted that two families viz., Co 7704 x Co 8209 and Co 85002 x Co 86011 contributed a greater proportion of elite clones combining acceptable levels of cane yield and sugar yield. The top ten clones selected based on sugar yield from the stage II evaluation holds greater promise in the subsequent regional selection programs. Overall, the findings suggest that selection of the best families based on their mean performance and further selection of individual clones based on their sugar yield in early stages would improve the efficiency of selection and increase heritability in the genetic populations being tested.

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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.

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Cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is a serious pest of several crops throughout the world, representing millions of United States of America dollars worth of damage. This pest can adapt to various cropping systems in a wide geographical range and has high migratory potential. It features high fecundity and can develop resistance to almost all insecticides used for its management. Several investigations to develop microsatellite markers for H. armigera have not been successful because of the paucity of microsatellites in the lepidopteran genome. As well, collections of H. armigera from cotton fields of southern and western India were not yet studied for molecular genetic diversity. The current study aimed to screen publicly available expressed sequence tag resources for simple sequence repeats and assess their potential as DNA markers for assessment of gene flow between collections of southern and western India. We identified 30 polymorphic microsatellites for potential use in diversity analysis of H. armigera collections. Genetic diversity analysis revealed that the collections were widely diverse with population differentiation index (Fst) of 0.17. Furthermore, gene flow analysis revealed a mean frequency of private alleles of 11% within the collections. The microsatellite resources we developed could be widely used for molecular diversity or population genetic research involving this important pest of cotton and food crops.