Reproductive biology of vatica venulosa blume (Dipterocarpaceae)

Abstract

Vatica venulosa Blume has been included in the critically endangered A1c ver 2.3 categories according to the IUCN red list. Reproductive biology of V. venulosa Blume was carried out in July 2019–July 2020 at the Research Center for Plant Conservation and Botanic Gardens, Bogor, Indonesia. The research observed flower morphology, flower development, type of pollination, fruit and seed structures. V. venulosa is categorized as sub-annuals and hermaphrodite inflorescences. A few reproductive system aspects are cross-pollination, flower structure is heteromorphic with pin category (the location of the pistil is longer than the stamen) and protandrous. The flower visitor is an insect nymph of Thrips sp. (Thysanoptera: Thripidae) which are white and 1–1.5 mm in size. The percentage of blooming flowers was 32.25–37.93%, 26.89–29.27% pollinated flowers, 83.63–92.92% fall/dead flowers, fruit sets 13.17–1.51%. Physiological maturation of V. venulosa fruit at the age of 101±3–106±3 days after the flowers bloom. V. venulosa fruit is included in the exalbuminous category. The cotyledons are composed of a small lump resembling starch i.e. 42.48% carbohydrates.