Studies on heterosis and inbreeding depression in bottle gourd (Lagenaria siceraria (Mol.) Standl.)

An investigation was carried out in bottle gourd (Lagenaria siceraria (Mol.) Standl.) to study heterosis and inbreeding depression for yield and yield contributing characters in four promising crosses (Pusa Naveen x Local Round, Pusa Naveen x Pusa Santhusti, Pusa Sandesh x Punjab Bahar and Pusa Sandesh x Arka Bahar) involving six parents (Pusa Naveen, Local Round, Pusa Santhusti, Pusa Sandesh, Punjab Bahar and Arka Bahar). Relative heterosis and heterobeltiosis was found to be significant and negative for vine length, internodal length, number of nodes per vine, days to first male flower, days to first female flower, days to first harvest, days to last harvest in one or more crosses. Positive relative heterosis was observed for vine length, internodal length, number of nodes per vine, number of branches per plant, days to last harvest, number of fruits per vine, average fruit weight, fruit yield per vine and total soluble solids for most of the crosses. Significant positive heterobeltiosis was also observed for number of branches per plant, number of fruits per vine, average fruit weight, total soluble solids. Significant inbreeding depression coupled with significant relative heterosis and heterobeltiosis were observed in majority of the crosses for all the characters except for total soluble solids. This may be due to close relationship between heterosis and inbreeding depression (i.e. crosses showing high heterosis also exerted high inbreeding depression) and also due to non-additive gene action.