Biannual pollen production inLagerstroemia speciosa(L.) Pers. (Lythraceae)

Abstract

This study aims to analyse the flowering phenology and variation in total pollen production per tree in the natural populations of Lagerstroemia speciosa during seven successive years, i.e. 2006-2012. The production of flowers and pollen grains per tree varied intermittently every two years. In the mass production years, pollen production ranged between 9.48 × 10 8 and 9.8 × 10 8 , whereas in poor production years, the values were between 4.6 × 10 7 and 5.1 × 10 7 pollen per tree. The study also revealed that the reproductive phenophases of L. speciosa were highly variable in the individuals of the population during different years, henceforth the flowering period endured for three months. The maximum anthesis in this species occurred in the morning between 05:00 and 10:00. On an average, a flower took 2.5 to 3 hours for complete opening. Anther dehiscence occurred half an hour after anthesis. Bees of the genera Apis and Xylocopa were the main pollinators in L. speciosa. The visitation rates of pollinators were also different among individuals of the population, which varied from 0.62 to 2.82 visits/flower/hour with an average visitation of 1.68 ± 0.94 visits/flower/hour.

Role of pollen production in mating success in some tropical tree species

“…However, the present study was undertaken to understand the flower and pollen production behaviour of five tropical tree species, viz., Bombax ceiba, Erythrina stricta, Lagerstroemia speciosa, Mesua ferrea and Schima wallichii with reference to the setting of fruits. The information on the pollination and reproductive biology of the selected tree species is meagre except for the few studies done by Raju et al (2005), Khanduri et al (2013), Khanduri (2014) and Khanduri et al (2014). Although the taxonomic, ethnobotanical, medicinal and pharmacological dimensions of the selected tree species have been worked out so far (Subhashini et al 2011;Tavares et al 2011;Chanda et al 2013), the processes of pollen production and pollination systems have been grossly ignored.…”