SEED DEVELOPMENT AND GERMINATION STUDIES OF TWO TRUE MANGROVE SPECIES RHIZOPHORA MUCRONATA POIR AND BRUGUIERA CYLINDRICA (L) BLUME.

Abstract

The present study was carried out on phenological observations and reproductive characteristics including seed development, maturation and number of days taken for produce mature propagules/seeds by the selected two important mangrove species Rhizophora mucronata . Prior Bruguiera cylindrical (L) Blume of
the family Rhizophoraceae. An interesting adaptation noticed in true mangroves is that or those belonging to the family Rhizhophoraceae reproduce through a unique biological phenomenon called vivipary. In this mode of reproduction in the post fertilization the zygotes stay on the mother plant for a period 3-7 months until they mature in to seedlings or commonly called as propagules. The physiological maturity of seeds generally determined on the basis of accumulation of higher dry weight with maximum germination. In Rhizophora macronata physiological maturity of seed determined as 14th weeks after anthesis. The moisture content of the seed was decreased to with increase of dry weight. In Brugeiera cylindrica, the harvestable maturity can be fixed on 12th weeks after anthesis. It was based on the maximum dry weight. 2.4 gm with minimum fresh weight of 4.09 gm. The germination percentage of seeds was also maximum during that period.Seed maturation studies of Rhizophora mucronata indicate that the best collection time prevails from April to June and in Bruguiera cylindrica the best seed collection time prevails from May to July.