Heterosis and combining ability for tuber dry matter and yield in potato (Solanum tuberosum L.) over two clonal generations under short-day subtropic conditions

The potato processing industry requires cultivars with high tuber dry matter and acceptable colour of processed products. Hence an attempt was made to find out the extent of heterosis, type and nature of gene action and the suitable parents for tuber dry matter, yield, tuber number and average tuber weight. Fourteen parents and their 40 progenies from factorial (10 4) mating design were evaluated for two clonal generations. Data were recorded and subjected to heterosis and combining ability analyses. In general, progenies were better than mid parent value for number of tubers, lower for average tuber weight and as good as for yield and dry matter. Mean squares due to various sources including interactions with generations were significant for all the characters. Both additive and non-additive gene actions were equally important for various characters. Specific combining ability effects of crosses were related to general combining ability effects of the parents involved. Use of at least one parent with good general combining ability resulted in high-performing heterotic progenies for various characters. Superior parents and hybrids for yield and dry matter were also identified.