Hermaphrodite Flower Induction by Silver Nitrate (AgNO3) Application and Possibility of Crossbreeding in Pointed Gourd (Trichosanthes dioica Roxb.)

摘要

This study aimed to reveal the effect of silver nitrate on sex modification in dioecious pointed gourd (Trichosanthes dioica Roxb.) originated in South Asia, and to explore the possibility of crossing among female plants. Three concentrations (50, 100, and 200 ppm) of silver nitrate were applied as foliar spray on female vines of three pointed gourd accessions. Application of 50 ppm silver nitrate found as effect to induce maximum proportion of hermaphrodite flowers with expanded duration irrespective of genotypes. The percentage of hermaphrodite flower induction was decreased with the increase of silver nitrate concentration. Viability of pollen grain (92.6-94.0%) in 100 ppm silver nitrate induced hermaphrodite flowers were as similar as that of normal male flowers (95.3%). Crossing among different female genotypes with pollen taken from the induced hermaphrodite flowers, produced same size of fruits of normal crossing. Seeds obtained from such crossing germinated successfully and seedlings grew vigorously as that of normal seeds. This technique seems to be useful for crossings among female plants that have suitable characters and facilitate a breeding of new variety in pointed gourd.