Inter-specific variations in chiasma frequencies and terminalization in Chlorophytum Ker-Gawl.

Chromosomal Behaviour and Seed Production in Chlorophytum comosum (Liliaceae).

“…The terminal chiasma and the absence of chiasma formation observed could be responsible for the occurrence of univalents. The chiasma frequency per microsporocyte in diakinesis found here (M=23.10) was lower than the frequency observed in the same species (M=31.52) by Patil and Gandhi (1988). These authors did not find any bivalents with one chiasma, whereas we detected a mean of 5.45 bivalents among the fourteen present in each microsporocyte, with only one chiasma and more than a half of these (M=2.92) showing a terminal chiasma.…”

“…These authors did not find any bivalents with one chiasma, whereas we detected a mean of 5.45 bivalents among the fourteen present in each microsporocyte, with only one chiasma and more than a half of these (M=2.92) showing a terminal chiasma. Since chiasma frequency (Rees and Thompson 1958, Pagliarini 1980, Karp and Jones 1982, Lein and Lelley 1987 and chiasma distribution (Jones 1967, Karp and Jones 1983, Lein and Lelley 1987 are under genetic control, the difference between the plants analysed here and the plants analysed by Patil and Gandhi (1988) could be of a genetic nature. Absence of chiasma and precocious chiasma terminalization have been reported to be respon sible for the occurrence of univalents in maize (Pagliarini 1980(Pagliarini , 1989, Aptenia cordifolia (Pagliarini 1990), and Pilocarpus pennatifolius (Pagliarini and Pereira 1992).…”

“…The genus Chlorophytum comprises about 234 species distributed in tropical and sub tropical regions, most of them occurring in Africa , its possible centre of origin (Patil et al 1987). Many species of this genus have been studied from cytotaxonomic and cytogeographic points of view (Baldwin and Speese 1951, Mukherjee 1957, Naik 1976, 1977.…”

“…Many species of this genus have been studied from cytotaxonomic and cytogeographic points of view (Baldwin and Speese 1951, Mukherjee 1957, Naik 1976, 1977. The basic chromosome number for the genus has been suggested to be x=8 and 7 , possibly derived as a secondary number from x=4 (Patil et al 1987) . Some species of Chlorophytum are being studied in terms of economic and medicinal aspects (Tarafder 1983, Wolverton et al 1984.…”