Studies on the Megasporogenesis, Microsporogenesis and Development of Female and Male Gametophyte of Capsicum annuum L.

This paper studies the megasporogenesis, microsporogenesis and development of female and male megasporogenesis of Capsicum annuum L. by means of routine paraffin-embedded sectioning technique. The results are as follows: Five anthers, four locule. The anther wall comprises an epidermis, endothecium, 2 or 3 middle layers and glandular heterotypic tapetum. Towards the outer side the tapetum is derived from the primary parietal layer, whereas on the inner side it develops from the cells of connective. Both of the two kinds of tapetum contribute to the development of male gametophyte. Archesporium in the stamen is multicellular. There are two rows of microspore mother cells on the transverse section of each locule. Meiotic divisions in microspore mother cells are followed by simultaneous cytokinesis and result in tetrahedral and decussate tetrads. Pollen grains are three-porate and two-celled at mature stage. Free-central placentation and polyovulatus. The ovule is anatropous, unitegmic and tenuinucellal with the endothelium. The single archesporial cell functions directly as megaspore mother cell. The later undergoes meiotic divisions and develops into linear tetrad. The third megaspore is the functional one which undergoes three times mitosis and develops into a mature embryo sac with 7 cells and 7 nuclei. Embryo sac is of Polygonum type. The development of stamen is earlier than that of pistil, they synchronize before blossom. When blossom, the dispersed pollen grains arrive at the stigma of its own pistil so that self-pollination is completed. Here we discuss the derivation of heterotypic tapetum, characteristics of its morpha and structure, and relationship between the tapetum and male sterlity.