Intraspecific differentiation of Astragalus clerceanus s. L. (Craccina, Fabaceae): environmental, genetic and embryological aspects.
The genotypic diversity, embryological, and anthecological characteristics in six natural and one introduced populations of Astragalus clerceanus s. l. were investigated. The information about significant environmental differences in the two parts of its area was given (including the decided preference limestone and dolomite by the southern plants and avoidance such substrates - by the northern). According to the allozyme analysis the high levels of genetic polymorphism was shown and unique alleles were identified in all populations. In the most populations heterozygote deficit was determined that was probably due to the inbreeding phenomenon. On the several allozyme loci allele frequencies differences were marked even in geographically close populations, suggested the presence of the gene drift in isolated populations. Genetic divergence (difference is significant p < 10-5) between southern and northern groups of populations, as well as its large embryological differentiations were shown. Therefore, the separation of Astragalus clerceanus s. l. in two subspecies was valid that demonstrated considerable microevolution transformation of the species.