Vol 4, No 1 (2006)

The genetic diversity of 34 species of the genus Solanum was studied using chloroplast (cp) DNA and mitochondrial (mt) DNA specific PCR primers. 11 cpDNA haplotypes and 16 mtDNA haplotypes were discovered. Traditional botanical taxonomy of potato species was not supported by cpDNA data. Cladistic relationships of 34 species support their geographical and genome differentiation. A derived clades contains E-, B- and A-genome species of the section Petota suggesting a coevolution of chloroplast and nuclear genomes.

The chloroplast genomes of 67 accessions of Hordeum vulgare L were surveyed for simple sequence repeat polymorphism. Seven SSR loci were investigated, trnL/trnF and psbI-trnS intergenic regions, as well as two regions 3' trnS genes were polymorphic. The rare variants of these loci were revealed and five rare accessions were found. Our results show an extremely low level of cpDNA polymorphism of cultivated barley.

Particularities of the morphological R-variants appearance in periodic culture of two strains of Bacillus thuringiensis were investigated. It is shown that both in optimum and in stressful conditions (рН 9,4) the R-variant frequency was increased in stationary phase only. Results from Luria and Delbrück's fluctuation test established that the frequency of R-variants is independent of the number generations passed and the number of colonies under investigation. Majority of R-variants was asporogenous and acrystalligenous, but didn't differ from original S-variants in set of others diagnostic characteristics that are significant for type. Mating between S- and R-variants has shown that the presence of R-variants in culture provides increasing to efficiency of recombination between of the subspecies.