Microsporogenesis and Male Gametophyte Development of Seedless Grapevine Cultivars Nedelchev VI-4 and Rusalka 1
Agricultural University, Viticulture Deptartment, BG-4000, Plovdiv, Bulgaria
ROICHEV, V., 2000. Microsporogenesis and male gametophyte development of seedless grapevine cultivars Nedelchev VI-4 and Rusalka 1. Bulg. J. Agric. Sci., 6: 285-290
Microsporogenesis and male gametophyte development of two hybrid seedless grapevine cultivars have been studied by means of microscopy observations of flowers in dynamics. It has been established that anther walls are constructed of epidermis, endothecium, intermediate layer and polynuclear tapetum of secretory type. Microsporogenesis is effected without deviations by simultaneous type. Microsporous tetrads are tetrahedral with scarce occurrence of the isobilateral type. No polyads or micronuclei have been observed during the formation of the mononuclear microspores. Male gametophyte development is completed with the formation of binuclear pollen grains of normal shape and size. The character of the exine surface ultrastructure and the location of the elements of the pollen aperture complex show that it is fertile.
Key words: microsporogenesis, gametophyte, seedless grapevine cultivars