Heterosis and inbreeding depression in bottle gourd [Lagenaria siceraria (Molina) Standl]

Thirty six F₁ hybrids of bottle gourd and fifteen parental lines were tested out to find out the extent of heterosis and inbreeding depression of fruit characters viz. days to fifty percent germination, days to first male flower anthesis, days to first male flower anthesis, node number to first male flower, node number to first female flower, vine length (m), number of nodes per vine, number of primary branches per plant, length of fruit (cm), weight per fruit (kg), number of fruits per plant and fruit yield per plant. The negative and significant heterosis is desirable for days to fifty percent germination, days to first male flower anthesis, days to first female flower anthesis, node number to first male flower, node number to first female flower. The positive and significant heterosis is desirable for vine length, number of nodes per vine, number of primary branches per plant, length of fruit, weight per fruit, number of fruits per plant and fruit yield per plant. Most of the crosses showed positive and significant heterosis over standard variety and better parents. The cross combinations DK x NDBG-104 and PBOG-22 x Pusa Naveen for days to fifty percent germination, VRBG-18 x NDBG-104 for days to first male flower anthesis, VRBG-105 x PSPL and VRBG-18 x NDBG-104 for days to first male flower anthesis and DK x PSPL for node number to first male flower, PBOG-22 x NDBG-104 for node number to first female flower, AD-1 x NDBG-104 showed negative and significant heterosis over standard variety and better parents, respectively. As negative heterosis is desirable for these characters. The cross combinations AD-1 x NDBG-104 for vine length, VRBG-1 x PSPL and DK x PSPL for number of nodes per vine, VRBG-1 x PSPL and AD-1 x Pusa Naveen for number of primary branches per plant, VRBG-44 x NDBG-104 and VRBG-112 x PSPL for length of fruit, VRBG-148 x NDBG-104 for weight per fruit, DK x Pusa Naveen for number of fruits yield per plant and VRBG-44 x Pusa Naveen for fruit yield per plant showed highly positive and significant heterosis over standard variety and proved better parents, respectively. In general many crosses exhibited significant heterosis in F₁ and also revealed inbreeding depression in F₂ populations.