Studies in the embryology of the diandrous orchidCypripedium cordigerum (Cypripedieae, Orchidaceae)

Pollinium development in Spiranthes sinensis (Pers.) Ames.and Cymbidium pendulum SW: a comparative study

“…The subfamily Epidendroideae shows a remarkable variation where anther wall may be 4, 5, 6 or even 7-layered due to 1-3 middle layers and 1-2 layered tapetum. Generally, a 4-layered anther wall is designated as 'Monocotyledonous' type but more than 4-layered anther wall is called 'Massive' type (Sood and Rao 1988) that supports the present investigation. In C. pendulum, anther wall underwent repeated mitotic divisions and formed an anther beak facing the rostellum.…”

“…In S. sinensis, microspore tetrads separated out from each other, whereas, in C. pendulum, tetrads further united to form a pollinium in each theca. Simultaneous cytokinesis and formation of different type of microspore tetrads in varied percentage is a common feature in Orchidaceae (Sood and Rao 1988) except few taxa where cytokinesis is of successive type (Swamy 1943, Arekal and Karanth 1981, Aybeke 2012. During microgametogenesis, each microspore produced a smaller, lenticular, generative cell and a larger 'spherical' vegetative cell.…”

Anatomical development of the pericarp and seed of Oncidium flexuosum Sims (ORCHIDACEAE)

“…This author described the embryonic sac as being composed of six nuclei, which differs from the eight nuclei found in O. flexuosum. Studies involving various genera of the family showed both embryonic sacs containing eight nuclei (Sood and Rao, 1986;Sood and Sham, 1987;Sood, 1986) and embryonic sacs with smaller numbers of nuclei (Law and Yeung, 1989;Maheshwari, 1950;Poddubnaya-Arnoldi, 1960, 1967Sood and Rao, 1988;Swamy, 1945). Swamy (1949a,b) and Law and Yeung (1989) suggest that there is a tendency for the reduction of the number of embryonic sac nuclei in Orchidaceae, with several tribes containing six, five or only four nuclei.…”

Orchid Biology: Reviews and Perspectives, VIII

“…bieolor Nishimura and Tamura, 1993;see C. bieolor Swamy, 1949Sood and Mohana Rao, 1988Carlson, 1940Fig. 6-2G15 -62G17 Swamy, 1943a; Fig.…”

“…6-1F) led to the discovery of double fertilization, a process which is now known to occur in all flowering plants. 6-1B) 6; Mahdu Sharma, India (Sharma and Vij, 1981; Sarvesh Kumar Sood, India (Sood, 1983(Sood, , 1984a(Sood, , 1984b(Sood, , 1985(Sood, , 1986(Sood, , 1988a(Sood, , 1988b(Sood, , 1989; Sood and Mohana Rao, 1988; Sood and Sham, 1981) ; B. G. L. Swamy ( Fig. 6-11) also studied orchid stigmas and pollen, as well as pollination and its effects, but failed to grasp or properly convey the importance of his findings.…”