Pollination Ecology and Fruiting Behaviour in Strychnos nux-vomical. (Loganiaceae)

Abstract

Aims: Strychnosnux-vomica is a valuable drug plant. Knowledge on its breeding system and pollination ecology will assist future research on genetic improvement for higher yield attributes. Place and Duration of Study: The study was conducted in the Silvicultural Research Station, Bhubaneswar, Odisha, India between 2016-2018. Methodology: Pollination experiment was conducted for autogamy, geitonogamy, xenogamy, apomixis and open pollination by allocating three hundred flowers for each experiment. Phenological events, pollinator visit and their behaviour were recorded at regular intervals. Results: Pollination studies in Strychnos nux-vomica revealed mixed mating system in its flowers. Flowers are small, greenish-white, bisexual, nectariferous and emit mild sweet odour. They open during evening hours and offer pollen and nectar to the visitors.  Bees, flies, wasps, butterflies, beetles and birds are the pollinators. Apis dorsata and Euploea core are the principal one and makes diurnal visit between 7.00-17.00 hours.  The anther dehiscence starts at 16.00-16.15 hours. The capitate stigma receptive to pollen germination at 17.30-18.00 hours and remain in receptive state one day after complete anther dehiscence. Flowers favour cross-pollination (29.78-60.26%) however selfing is also possible (17.94-39.74%). Conclusion: Information on breeding system and pollination ecology will be helpful in developing a breeding strategy for higher fruit set and seed yield.