Additional Evidences of Cytogenetic Differentiation in Certain Linum Species with 2n=30 Chromosomes

Abstract

Meiotic studies in Linum usitatissimum L., Linum angustifolium Huds. and Linum africanum L. were carried out and 2n=30 chromosome number was confirmed. Among the 3 species, mean chiasmata per bivalent varied between 1.82 to 1.90 maximum being in Linum africanum. Secondary association of chromosomes were observed in Linum usitatissimum as well as in Linum angustifolium. However, the 2 species differed in number of bivalents associated. In Linum angustifolium as many as 8 bivalents were involved in association where as in Linum usitatissimum not more than 4 bivalents participated in such a association. In both the species, 11 II+2 IV configuration was most frequent. In all the species early separation of chromosomes in 1-3 bivalents was noted. In Linum angustifolium one of the secondarily associated bivalent invariable showed early separation. Despite secondary association and early separation, meiosis was normal in all the species. Pollen and ovule fertility was also normal. Cytological data in general revealed cryptic chromosomal differences among the 3 species. Linum angustifolium appeared closer to Linum usitatissimum than to Linum africanum. © 1982, Japan Mendel Society, International Society of Cytology. All rights reserved.