Meiotic Regularity in Diploid and Eutetraploid Meadow Fescue

Authors: Bilal DENİZ

Abstract: In this research study. metaphase 1 (MI) chromosome pairing. number of chromosome arms bound and anaphase 1 (AI) segregations were studied in diploid cultivar S.215 of meadow fescue and its induced eutetraploid C_2 generation (Tetra- S.125). In additon. relationships were found out between cytological characteristics at first meiotic division in both ploidy Ievels. Diploid meadow fescue had very regular meiosis mainly with ring bivalents at MI and mostly with balanced chromosome segregations at AI. In these plants. the number of chromosome arms bound was very high with average 12.08 per cell. Tetra-S.125 plants had somewhat irregular meiosis with univalents, trivalents and hexavalents at MI. but bivalent and quadrivalent pairings were often observed. AI segregations were generally balanced. and some unbalanced ones were also seen. In comparison with the ones found in diploids the number of arms bound of the tetraploids was almost twice per cell. In both ploidy Ievels. the frequency of AI cells with Iagging univalents was positively and significantly associated with the frequency of MI ceils with I's. Similar relationships were also observed between other cytological characteristics at first meiotic division.

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