Cytological Studies in <i>Fimbristylis</i> (Cyperaceae)

Abstract

Fimbristylis comprises about 300 species (Willis 1966). Compared to the size of this taxon the cytological information available is scanty (Tanaka 1937, 1939, Dnyansagar and Tiwari 1956, Sharma 1962, Sharma and Bal 1956, Chuang et al . 1963, Gadella and Kliphuis 1964, Baquar 1969, Murin and Chaudhri 1970, Mehra and Sachdeva 1971, Sanyal and Sharma 1972, Nijalingappa 1972, 1973. The present contribution deals with cytological studies of 13 species from southern India. Material and methodsThe plants were collected near Bannerghatta and Bhadravati (Mysore State). The voucher specimens have been deposited in the Herbarium of the Department of Botany, Bangalore University, Bangalore. For the study of somatic chromosomes root tip squash preparations were made adopting the technique of Tjio and Levan (1950). Several metaphase plates were examined for each species, and the one with well spread chromosomes was selected for photomicrography, drawing and measure ments. For meiotic studies spikelets were fixed in acetic-alcohol (1: 3) for 24 hours and anthers were squashed in acetocarmine. These preparations were made permanent by using n-butyl alcohol-acetic acid series. Results A. Karyotypes

Cytological studies in Cyperaceae with special reference to its taxonomy. II.

“…From morphological and cytological considerations a distinct specific status has been suggested for this taxon (Patnaik and Rath under pulbication). Of the six Indian species of Fuirena, five species have been cytologically worked out (Rath andPatnaik 1974b andNijalingappa 1977) and the genus was found to be characterised by three distinct basic chromosome numbers of x=18, 19, 26. Fuirena uncinata, F. ciliaris and F. trilobites are a group of very closely allied species.…”

“…However, F. wallichiana (n=38) is the only tetraploid species (Nijalingappa 1972) known in the genus. F. umbellata stands out as a distinct species by its ecological preference, robust habit and comparatively larger spikelets.…”

“…Notable among them are Sanyal (1972), Sanyal and Sharma (1972). Rath andPatnaik (1974a and1974b), Nijalingappa (1975) and Mehra and Sachdev (1975). A survey of all these reports reveals that not only most of the genera are characterised by series of aneuploid numbers but there is great disparity in the findings of different workers in respect of chromosome numbers for the same species.…”

Karyotypic studies on certain members of Cyperaceae from Punjab, north west India.

“…32, 33). This explains the existing polymorphicity in the species as earlier noted by Nijalingappa (1973) b) Nature of centromere Presently, out of 16 taxa studied, localized centromere have not been observed in two taxa, namely Carex fedia and Scirpus triqueter. According to the earlier studies it had been pointed out that all the species of Carex possess small sized chromosomes and dffuse centromere (Davies 1956a, b).…”

“…chromosome). Nijalingappa (1973) On the basis of SI values, in genus Fimbristylis, slightly symmetrical, moderately symmetrical as well highly symmetrical karyotypes are met within different species and even in the same species, F. dichotoma (n=10).…”