Reproductive Biology of Wrightia tokiae D.J. Middleton in Khunpawor National Park, Tak Province

Abstract

The reproductive biology of Wrightia tokiae D.J. Middleton was studied in Khunpawor National Park, Maesot district, Tak province, Thailand during October 2022–September 2023. Floral biology and development, pollination, percentage of fruit set and diversity of insects were investigated using an air-flight malaise trap during flower blooming. The flowers of W. tokitae were generally in bloom from late May to June. Flower buds developed to inflorescence maturity in approximately 9–10 days. The W. tokiae flower was perfect, with cyme type inflorescence, the corolla light orange and rotate. while the fallen corolla was reddish. The pollen grains were monad and spherical. One flower produced, 6,633.40±750.50 pollen grains and contained 38.60±2.99 ovules. The average pollen-to-ovule ratio was 170.04±9.58, classified as facultative autogamy. The open-pollinated flower fruit set rate was 10.24 (n=127), while there was no successful outcome in the self-pollination set. The fruit set rates indicated that pollinators were required for reproductive success. In total, 20 species of visiting insects were identified to W. tokiae flowers (all moths in the Lepidoptera order). These insects play an important role in the pollination of W. tokiae as its flowers bloom at night.