Cytomixis and unreduced pollen formation in some Festuca L. Species of Iran

Abstract

Nine populations of 4 Festuca species (genus Festuca, Poaceae) were studied for meiotic characteristics including chiasma frequency and distribution as well as chromosomal association and segregation. The species studied showed the presence 2n = 2x = 14 and 2n = 6x = 42 chromosome number. The chromosome number of F. akhanii is new. Two populations of allohexaploid species of F. arundinacea, F. valesiaca as well as one population of F. akhanii formed quadrivalents in metaphase of meiosis-I, possibly due to the ocurrence of chromosomes structural changes. Diploid and tetraploid species differed significantly in their relative cytogenetic characteristics, indicating their genomic differences. Almost in all the populations studied laggard chromosomes and stickiness were observed which might bring about some degree of pollen infertility. Chromatin/chromosome migration occurred in most of the species studied resulting in the formation of aneuploid and unreduced meiocytes which in turn may lead to the formation of unreduced pollen grains. Cytomixis and 2n pollen formation in the genus Festuca is reported or the first time. © 2007 Taylor and Francis Group, LLC.