Diagnostic Morphological Characteristics of Bruguiera, Ceriops, Kandelia and Rhizophora Pollen (Rhizophoraceae) in Peninsular Malaysia

Rhizophoraceae is a plant family in mangrove forest with approximately 16 genera and 120 species and seven genera and 17 species are found in Peninsular Malaysia. Palynology study in mangroves to investigate the importance of pollen morphological characteristics and adaptation to its environment is still meagre. The objectives of this study were to list the common features, variations and diagnostic features of pollen morphology among species and genera in the Rhizophoraceae family. The methods involved acetolysis techniques and observation under light and scanning electron microscopes. The results showed that there are two pollen classes which are tri-zono-colpate and tri-zono-colporate. All the species studied have small size (10-25 mu m) and spheroidial shaped pollen except Rhizophora x lamarckii with subprolate pollen. Two types of exine ornamentation were found in Bruguiera, i.e. scabrate-perforate (B. cylindrica, B. parviflora. B. hainesii and B. sexangula) and psilate-scabrate (B. gymnorhiza). On the other hand, the genus Ceriops and Rhizophora stylosa have perforate exine ornamentation and R. apiculata and R. mucronata have exine ornamentation perforate-reticulate. Dichotomy key for species and genus identification has been constructed based on the findings. As a conclusion pollen morphological characteristics have taxonomic value especially for the genus and species differentiation and identification in the family Rhizophoraceae.