Cytology of Some Sedges from N.W. India

Cytological studies in some members of cyperaceae.

“…Ascopholis gamblei with 2n=80 indicates that 5 is the basic number for the genus Ascopholis. Perusal of literature reveals that the higher or lower basic numbers may not be the true basic numbers in the phylogenetic sense as they might have secondarily derived from the original basic number of x=5 (Love, Love and Raymond 1957, Mehra and Sachdeva 1975, and Ramakrishnan and Ramachandran 1976. Structural changes including fragmentation and duplication of single or whole set of chromosomes are responsible in bringing about this wide range of chromosome numbers.…”

“…Sharma and Bal (1956) were the first to study the cytology of Indian species of the Cyperaceae. Since then, several Indian species were investigated by various workers (Mehra and Sachdeva 1975, 1976, 1979, Nijalingappa 1973-1975, 1977, Rath and Patnaik 1974, Sanyal 1972and Sanyal and Sharma 1972. Patnaik and Rath (1983) have discussed the chromosomal evolution in the family by critically analysing the available cytological data.…”

Cytological Studies of 4 Species of the Genus Kobresia (Cyperaceae) Collected from Nepal Himalaya

“…122, may have arisen through polyploidization from ancestors such as K. myosuroides or K. esenbeckii as they have the number of 2nϭ52-56, 58, and 60-66. Mehra and Sachdeva (1976) suggested that chromosome numbers in the genus Kobresia showed ploidy series on 3 basic numbers, xϭ8 (2nϭ32, 40, 72), xϭ9 (2nϭ54, 72), and xϭ13 (2nϭ52, 78), and other chromosome numbers, 2nϭ58 and 76 originating from secondary aneuploidy. In the present study, our results also suggested that the chromosomal evolution in unispicate Kobresia species may have Knaben and Engelskjøn (1967) been caused by both polyploidy and aneuploidy.…”

“…36, 52-56, 58, 60-66, 70-76, 80, ca. 122 (Flovik 1943, Holmen 1952, Löve and Löve 1956, Jørgensen et al 1958, Knaben and Engelskjøn 1967, Johnson and Packer 1968, Zhukova 1969, Krogulevich 1971, Poghosian et al 1971, Zhukova and Petrovsky 1976, 1980, Mehra and Sachdeva 1975, Probatova and Sokolovskaya 1988, Hoshino et al 1993, 2000, Roalson 2008). However, most of these cytological works used materials collected from the circumpolar regions, and only 2 of the species examined were collected from the Himalayas.…”

“…However, most of these cytological works used materials collected from the circumpolar regions, and only 2 of the species examined were collected from the Himalayas. Mehra andSachdeva (1975, 1976) reported chromosome numbers of 2nϭ80 for K. royleana (Nees) Boeck., from Kashmir Himalaya in NorthWest India, and Hoshino et al (2000) reported 2nϭca. 122 for K. nepalensis (Nees) Kük.…”