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

Abstract

Pointed gourd (Trichosanthes dioica) is a perennial and
vegetatively propagated cucurbitaceous vegetable grown
for its tender fruits, and the occurrence of harder seeds
reduces consumers’ preference. The present study was
undertaken to understand the mechanism of seedless fruit
development in pointed gourd. The period of rapid fruit
growth and development in pointed gourd took place
generally 3-7 days after pollination due to faster cell division
and cell enlargement. Significantly higher fruit growth
recorded 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 same
time no significant differences found at initial stage of fruit
development. The occurrence of various mechanisms of
seedless fruit development such as vegetative
parthenocarpy, stimulative parthenocarpy and
stenospermocarpy have been studied in details through
different pollination treatments in both seeded and seedless
clones. In seedless clone, the growth/development of seed
was normal for first 3-4 days after pollination and become
abnormal (aborted and degenerated embryo, shriveled and
disintegrated cotyledons, traces of aborted seeds yellowishwhite
in colour and zero per cent seed germination) indicate
the existence of fertilization and subsequent abortion of
fertilized embryo which confirms the occurrence of
stenospermocarpic seedlessness and absence of stimulative
parthenocarpy in pointed gourd.