Estimation of heterosis and combining ability for earliness and yield characters in pumpkin (Cucurbita moschata Duch. Ex. Poir)

Heterosis breeding is a potential tool to achieve improvement in quantity, quality, and productivity of pumpkin. A line x tester mating design was used to study standard heterosis for earliness and yield characters in pumpkin. An investigation was carried out during 2009 to 2010 with twelve lines and three testers at Department of Vegetable Crops, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore to study the heterosis and combining ability for earliness and yield characters. Evaluation of parents based on per se and general combining ability (gca) effects revealed that the parents Kasi Harit, Vadhalagundu Local and CO 2 were identified as the best genotypes for improvement of earliness and yield characters. The hybrids viz., Kasi Harit × Avinashi Local and Vadhalagundu Local × CO 2 had registered favourable values of mean, significant sca and standard heterosis for earliness and yield characters. Considering the per se performance, specific combining ability (sca) and the standard heterosis, the aforementioned hybrids had registered favourable values for the most important characters like earliness, number of fruits and yield of fruits. Further, these top performing F1 hybrids can be tested in different seasons over different locations for assessing their stability for high yield. Key words: Pumpkin, Per se performance, general combining ability (gca), specific combining ability (sca) standard heterosis.