Cytomorphological study of trigonella disperma (fabaceae) in Iran

Abstract

Chromosome number, meiotic behaviour and morphological characters related to habit and pollen grains were studied in 8 populations of Trigonella disperma of Trigonella sect. Ellipticae native to Iran. All populations are diploid and possess a chromosome number of 2n=2x=16, which is consistent with the proposed base number of x=8. This taxon displayed regular bivalent pairing and chromosome segregation at meiosis. However, some meiotic abnormalities observed included varied degrees of sticky chromosomes with laggards and bridges in metaphase I or II, asynchronous nuclei in metaphase II, desynapsis in metaphase I, and cytomixis. This paper reports the first known study of the meiotic chromosome number and behaviour of T. disperma. We evaluated and determined the population limits within T. disperma, employing multivariate statistics. Results from meiotic behaviour supports the phenetic grouping. We found a striking association between morphological patterns of the pollen grains, meiotic behaviour and habit morphology. Our results showed that Iranian populations of T. disperma represent the same chromosome, suggesting that the pollen size in different populations can be served to obtain useful information. The environment of origin seems to have an effect on the chromosomes within different populations. © 2011 The Japan Mendel Society.