A Cytotaxonomic study on Minuartia L. (Caryophyllaceae) in Iraq

Chromosome count, karyotypic character analysis, meiotic studies, monoploid karyograms and ideograms were performed in six taxa of Minuartia growing in Iraq (M. hamata, M. hybrida subsp. hybrida, M. intermedia, M. meyeri, M. picta and M. hybrida subsp. turcica). Species of M. hamata and M. meyeri showed 2n=2x=30 chromosome number, while M. hybrida subsp. hybrida and M. intermedia were diploid (26). The chromosome number (n=x) of six species was studied, and was found to be n=15 in M. hamata and M. meyeri, 13 in M. hybrida and M. intermedia, while in M. picta we recorded values of n= 11 and 14. Karyotype analysis of this species was first carried out in our study. Analysis of metaphases showed that the karyotype formula was mainly metacentric, submetacentric, and sub acrocentric. The sizes of the chromosomes were mainly small and very small. The course of meiosis varied from normal to abnormal. Abnormal microsporogenesis formation of two bridge chromosomes was detected in M. hamata and one bridge chromosome in M. intermedia and M. meyeri. Formation of laggard’s chromosomes was detected in M. hamata, M. meyeri and M. intermedia. As well as ring chromosome was showed in M. hybrida subsp. hybrida, also, some cells contain triad cell in metaphase stage instead four cells, as well as founded cell, contains two nuclei in same species which led to reduced pollen fertility and differences in pollen grain size.