ULTRASTRUCTURE AND HISTOCHEMISTRY OF ANTHER DEVELOPMENT IN MELIA AZEDARACH L.Abstract
We provide evidence of the structural development and distributional pattern of polysaccharides of the anthers in Melia azedarach L. The anthers of Melia azedarach L. is tetrasporangiate and basic type of wall formation is seen, it consists of six wall layers i.e. single layer of epidermis and endothecium, three middle wall layers and one tapetal layer. The primordium consists of a homogenous mass of meristematic cells which has a uniform distribution of insoluble polysaccharides. Sporogenous cells are moderate with PAS-positive and starch grains are present in all the wall layers. Meiocyte shows a moderate amount of carbohydrate with a prominent nucleus. The secretory cells are present near the connective and tapetum. Secretary cells are having abundant starch grains. Tetrahedral tetrads are present with surrounding thick callose walls with rich PAS-positive walls. The secretary type of tapetum is initially single-layered but some of the cells divide periclinally so that it becomes two-layered at vacuolated microspore stage. Middle wall layers are starting to degenerate at the tetrad stage. The pollen grains are tetracolporate and it contains abundant starch grains. The multiple fibrous thickening is formed in the dehisced stage with the rich content of polysaccharides. Dehiscence takes place through longitudinal slits and one middle wall layer is persistent at the dehisced stage.
P. L. Talawar * and S. N. Agadi
Developmental Biology and Histochemistry Laboratory, P. G. Department of Botany, Karnatak University, Dharwad, Karnataka, India.
21 October 2019
21 November 2019
26 November 2019
30 November 2019