Scientific and Technical Symposium on Sustainable Mangrove ...

Floral Biology <strong>and</strong> Pollination Ecology of Rhizophora mucronatain Gulf of Kachchh, Gujarat, IndiaP<strong>and</strong>ey, C. N. 1 <strong>and</strong> P<strong>and</strong>ey, R. 2ABSTRACTRhizophora mucronata is a viviparous mangrove species of the Family Rhizophoraceae. Thespecies is reported to be wind pollinated. However, the floral biology <strong>and</strong> pollination ecologyof the species has not been studied in detail in Gulf of Kachchh. Therefore, the present workhas been has involved detailed field <strong>and</strong> laboratory investigations regarding the flowerbiology <strong>and</strong> pollination ecology of R. mucronata. The study has been a part of a researchproject sponsored by the Ministry of Environment <strong>and</strong> Forest, Government of India. Theobjective of the research was to document the floral biology <strong>and</strong> pollination ecology of R.mucronata by examining the temporal relation between the anthesis, anther dehiscence,stigma receptivity <strong>and</strong> pollinator visitation pattern. Further, the chemical nature of floralexudate was also examined. The work has been carried out at two isl<strong>and</strong>s in Gulf ofKachchh viz. Pirotan <strong>and</strong> Bhens Bid Isl<strong>and</strong>s <strong>and</strong> one coast site at Sikka. The observationswere made during the flowering season of the c<strong>and</strong>idate species on the reproductivelymatured trees. The visitation pattern of floral visitors was observed at different levels toclassify them into floral visitors <strong>and</strong> pollinators. The chemical nature of the floral exudate wasexamined by the chromatography method.The flowers of R. mucronata have been clearly found to exhibit prot<strong>and</strong>ry. Further, theflower is inverted <strong>and</strong> exhibits herkogamy. These features facilitate cross pollinationincreasing the possibilities of cross breeding over self breeding. The corona of petals wasfound to regulate the pollen dispersal for a longer period after anther dehiscence. Further,the observed asynchrony between the anther dehiscence <strong>and</strong> stigma receptivity also appearto be promoting cross fertilization. Wind <strong>and</strong> water appear to be major pollinators. However,some insects have also been found to definitely play the role of pollinators. The floralexudate contains sugar indicating it to be the nectar which is also strongly suggestive thatfloral visitors also play a key role as pollinators.Key words: pollination, mangrove ecology, floral biology, Rhizophoraceae, prot<strong>and</strong>ry27