Botanical and Cytological Studies of Monodora tenuifolia Benth.

Abstract

This study investigated branching pattern, ecology of occurrence, palynology, cytology and phenology of Monodora tenuifolia using standard techniques. The branching pattern determines the shape of the canopy, which may be irregular when growing in the shade, or round when growing in the open. The pollens are tetrads, 10.15 µm in diameter, with pollen fertility of 92.24% (determined by using Cotton Blue in Lactophenol) and pollen tube germinability of 65.83%. Two simultaneous cytokineses were studied and the events of meiotic cell division were observed to synchronize. The chromosomes were well paired at pachynema as associations of regular bivalents, paired of ring 11 or rod 11, though univalents were occasionally observed. Monodora tenuifolia has the chromosome number equal to 2n = 16, showing a karyotypic formular of 1 acro (large) + 2 submet (medium) + 2 met (medium) + 2 acro (medium) + 1 met (small) chromosome in the 2B Stebbins category. The results indicate that the tetrad pollen grain of Monodora tenuifolia is an advantage, since up to four pollen tubes could be seen developing from the some pollen grains, while the karyotype is asymmetrical.