Evidence confirms the occurrence of stenospermocarpic seedless fruit development in pointed gourd (Trichosanthes dioica Roxb.)

Abstract

Pointed gourd (Trichosanthes dioica) is a perennial andvegetatively propagated cucurbitaceous vegetable grownfor its tender fruits, and the occurrence of harder seedsreduces consumers’ preference. The present study wasundertaken to understand the mechanism of seedless fruitdevelopment in pointed gourd. The period of rapid fruitgrowth and development in pointed gourd took placegenerally 3-7 days after pollination due to faster cell divisionand cell enlargement. Significantly higher fruit growthrecorded in seeded clone as compare to seedless clones(49.1% for fruit length, 16.7% for fruit diameter and 55.2%for fruit weight) at harvestable fruit maturity but at the sametime no significant differences found at initial stage of fruitdevelopment. The occurrence of various mechanisms ofseedless fruit development such as vegetativeparthenocarpy, stimulative parthenocarpy andstenospermocarpy have been studied in details throughdifferent pollination treatments in both seeded and seedlessclones. In seedless clone, the growth/development of seedwas normal for first 3-4 days after pollination and becomeabnormal (aborted and degenerated embryo, shriveled anddisintegrated cotyledons, traces of aborted seeds yellowishwhitein colour and zero per cent seed germination) indicatethe existence of fertilization and subsequent abortion offertilized embryo which confirms the occurrence ofstenospermocarpic seedlessness and absence of stimulativeparthenocarpy in pointed gourd.