Floral biology of cluster bearing and gynoecious population of sponge gourd (Luffa cylindrica)

Abstract

The floral biology studies were undertaken in two cluster bearing, two gynoecious and one improved genotypes of sponge gourd namely, VRSG-52-1, VRSG-52-2, 25Gy, 27Gy and Pusa Sneha at Seed Production Center of ICAR-Indian Institute of Vegetable Research, Varanasi (U.P.) in 2009. VRSG-52-1 was the earliest to produce male flower after 37 days of sowing while Pusa Sneha took longest period (42 days). The earliest and the latest genotype to produce female flower was VRSG-52-1 (47 days), 25Gy (47 days) and Pusa Sneha (50 days). This indicates the existence of variability in genotypes with respect to earliness. Corolla diameter of fully opened flowers varied among the genotypes. Male flowers were smaller in Pusa Sneha and larger in VRSG-52-1 and VRSG-52-2. Genotypes VRSG-52-1 and 27 Gy had the maximum ovary length of 5.90 cm. Incidentally, these two varieties also had the longest fruit size. Pollen viability was high in all monoecious genotypes under study, ranging from 95 percent in VRSG-52-1 and 98 percent in Pusa Sneha. Pollen germination was found to be good due to better pollen viability on the day of anthesis. Pollen size varied considerably within the genotype and also between the genotypes. Stigma was most receptive at the time of anthesis on the basis of percent fruit set (79 percent). Twelve hours after anthesis (7 percent) fruit set was observed where as 24 hours after and before anthesis, it failed to set fruit.