Meiosis and pollen grain development in Isolepis cernua F. Cernua (Cyperaceae)

Abstract

In this paper, cytogenetic studies and pollen grain development of Isolepis cernua (Vahl) Roem. & Schult. f. cernua (Cyperaceae) from Argentina are presented. The somatic chromosome number found is 2n= 54, being different from previous reports. Primary constrictions have not been observed, suggesting that they are holocentric chromosomes, as in many species of the family. The meiotic behaviour was described showing n= 27 and axial orientation of some of the bivalents. Three of four pollen nuclei degenerate while one of them completes the mitosis. These processes originate the pseudomonad, a characteristic feature in the Cyperaceae. This fact does not affect the pollen fertility wich is 98%. © 1999 Taylor & Francis Group, LLC.