Areas of pigmentation of retinal pigment epithelium overlying tapetum were noticed in all seven pugs dogs especially near the tapetal- non tapetal junction.
In dogs with absence of tapetum, position of OD could not be differentiated.
Moreover, it is reported that abnormal vacuolization of the tapetum during the tetrad stage was possible reason causing recessive GMS (Wan et al.
2, 3(I-II), the microsporangium wall of sterile anthers consisted of epidermis, endothecium, middle layer, and tapetum.
The single cell layer of tapetum surrounding the anther loculus is first recognizable at the early Microsporocyte stage .
anther wall followed the dicotyledonous type, which was composed of an epidermal layer, an endothelial layer, one middle layer and tapetum which is consistent with Davis 1966 and bagheri 2014.
Since the early days of orbicule-research, a positive correlation was hypothesised between the presence of orbicules and a parietal tapetum
type (von Ubisch, 1927; von Kosmath, 1927), although several species were identified with parietal tapetal cells but lacking orbicules (Huysmans et al.
The relatively large size of her eyes, the dense population of rods in her retina, and the tapetum
lucidum layer behind the retina are all adaptations aimed at maximizing night vision.
By the late sporogenous mass stage, when callose first appeared around the sporogenous cells, the tapetum
and parietal layer cells from male-sterile plants showed vacuoles (Fig.
When ascertaining tapetum
type, it is often necessary to examine several developmental stages of the anthers to avoid confusion.
On maturation of the anther, the sporangial wall consists of the epidermis and the endothecium, whereas the middle layers and tapetum
The aim of the present paper is threefold: (1) to give a concise state of knowledge about tapetum
and orbicules, (2) to enumerate the taxa where orbicules were reported to be present or certified absent, and (3) to visualize the systematic distribution of orbicules throughout the angiosperms by plotting the information on a dahlgrenogram.