Do honey bees affect pollination in the flowers of Ochlandra travancorica, an endemic bamboo of the Western Ghats?

Abstract

Ochlandra travancorica (Bedd.) Benth. ex Gamble is an economically crucial endemic reed of the Western Ghats, India. Mass populations of this reed directly affect global warming reduction through CO₂ fixation in the ecosystem. The floral biology and their impact on floral visitors were analyzed to understand the pollination mechanism of male and female phase flowers of O. travancorica. The bisexual flowers of O. travancorica were protogynous. The stigma started to lose its receptivity before the dehiscence of anthers, and the alien pollen was expected to maintain genetic variations in the reed population. The separate flowering phases of O. travancorica indirectly entail self-incompatibility to ensure genetic diversity among the populations. Based on the breeding experiments conducted, it was concluded that O. travancorica was self-incompatible (no fruit set in autogamy). The highest fruit set (70.4%) was recorded in open pollination, where the flowers were exposed to both wind and insect visits. The statistical differences recorded between the flowering phases and the Visitation Rate Index indicated that the male phase has been reported with higher visitation rate by Apis sp. due to the availability of floral rewards. The analysis of variance (two-way) results have confirmed the differences in insect visitation in both flowering phases. It is the first case of a honey bee pollination system identified in O. travancorica. It provides clear evidence for the hypothesis that it is an adaptive trait of the fruit-setting behaviour of O. travancorica by Apis sp.