Selection of lines from segregating generations and breeding hybrids to exploit heterosis or heterobeltiosis is an effective tool for improving economically important traits in the genus Capsicum. The objective of this study was to identify high potential parents to obtain high-yielding F1 hybrids using a Line × Tester (8 × 2) mating design in the Habanero pepper improvement programme. Ten parents and 16 hybrids were evaluated in order to determine their values of general combining ability, specific combining ability, heterosis, and heterobeltiosis. Parent NKA-11 had the highest values of GCA for different quantitative variables of the fruit, which does it suitable for future improvement works, and tester RNJ-04 showed the highest value of GCA for fruit length. The quantitative variables evaluated confirm a significant genetic variability among the Habanero pepper genotypes studied. The best hybrids were NEK-03xRNJ-04, NBA-06xRNJ-04, AKN-07xRNJ-04, and RKI-10xRNJ-04, which showed their high productive potential with values between 3.13 and 4.92 Kg/Pta, a quality, that would open to them the national market for fresh consumption. Based on the GCA values of the parents and heterosis of the progenies, it is concluded hybridization would be the most appropriate genetic improvement method to increase both yield (YP) and the number of fruits for plant.

Genetic analysis of sorghum resistance to stem-borers was performed in a 6 × 6 diallel cross. The results indicated that resistance to stem-borers is polygenically inherited. F1 hybrids did not differ significantly from mid-parental values suggesting intermediate inheritance. However, resistance was partially dominant to susceptibility. Combining ability analysis showed that resistance to primary damage, i.e. % ‘dead heart’ was governed by both additive and non-additive type of gene actions while secondary damage, i.e. % stem tunnelling was governed predominantly by additive gene action. It was noted that the inheritance patterns of primary and secondary damage were different. Tunnel length showed positive correlation with the number of larvae per plant and negative association with plant height, but had no correlation with grain yield per plant. On the basis of larvae recovered from the tunnelled plants, Chilo partellus was found to be the predominant stem-borer species followed by Sesamia calamistis, Eldana saccharina and Busseola fusca. Significance of genetic studies of host plant resistance in deciding breeding strategies for insect resistance has been discussed.