Diploid and Tetraploid Chromosome Races in <i>Fimbristylis ovata</i> (Cyperaceae)

Abstract

Sharma and Bat (1956) and Sanyal and Sharma (1972) studied the cytology of Fimbristylis ovata (=F. monostachya (L.) Hassk.) from northern India. In the course of cytological investigations of the species of Fimbristylis from southern India, 2 populations of F. ovata (Burm. f.) Kern with different chromosome numbers have been encountered (Nijalingappa 1972). The present contribution deals with the karyotype and meiosis of the 2 populations. Materials and methodsThe materials were collected from Bangalore (Coll. No. F-150) and also from Dharwar (Coll. No. F-196) situated about 420km north west of Bangalore. For the study of somatic chromosomes, root tip squash preparations were made following Tjio and Levan's (1950) aceto-orcein method. Several metaphase plates were examined from different temporary preparations, and those with well spread chromosomes were selected for karyotype analysis. For meiotic studies, spikelets were fixed in acetic-alcohol (1:3) for 24 hours and young anthers were then squashed in acetocarmine. The Voucher specimens have been deposited in the

New chromosome counts in Brazilian species ofRhynchospora(Cyperaceae)

“…Chromosome number and length in 14 species of Rhynchospora. Species are organized according to Kükenthal (1949Kükenthal ( , 1950Kükenthal ( , 1951 Vanzela et al 1996Vanzela et al , 2000Luceño et al 1998), and other genera of Cyperaceae, such as Carex (Davies 1956), Isolepis (Dopchiz and Poggio 1999), Fimbristylis (Nijalingappa 1975), Scleria (Yano and Hoshino 2007) and Eleocharis (Da Silva, González-Elizondo, Rego et al 2008;Da Silva et al 2010). Our data are in agreement with Greilhuber (1995) who considers the holokinetic chromosomes a synapomorphy of Cyperaceae.…”

“…Initially a basic number x = 5 was proposed by Löve et al (1957) for Cypercaeae. Recently, it has been suggested for Fimbristylis (Nijalingappa 1975), Rhynchospora (Luceño et al 1998;Vanzela et al 2000) and Eleocharis (Da Silva et al 2005Silva et al , 2010Da Silva, González-Elizondo, Rego et al 2008). However, the basic numbers x = 6 and 9 were also found in Rhynchospora, which are considered secondary (Luceño et al 1998;Vanzela et al 2000).…”

A Synopsis of Chromosome Number Variation in the Cyperaceae

“…The family is well known, along with the Juncaceae, for having a suite of cytological peculiarities including: psuedomonad pollen grain development (Juel, 1900;Stout, 1913;Tanaka, 1941); diffuse kinetochores ; postreductional meiosis (Wahl, 1940); and chromosome fission and fusion, often referred to as agmatoploidy Faulkner, 1972;Hoshino, 1981a;Cayouette & Morisset, 1985, 1986a, 1986bLuceno & Castroviejo, 1991;Luceño, 1993Luceño, , 1994Luceño, et al 1998;and others). While there have been some reports of localized kinetochores in some Cyperaceae genera (Fimbristylis-Sharma & Bal (1954, Nijalingappa (1975a), and Rath & Patnaik (1977); Eleocharis- ; Scirpus-Sanyal & Sharma (1972a); Lipocarpha- ; Cyperus- ), these reports have been questioned and it has been suggested that non-localized centromeres, i.e. the diffuse kinetochore condition, is a synapomorphy for the Cyperaceae and Juncaceae clade (Greilhuber, 1995).…”