Karyological, Molecular and Cytogenetical Studies on Tree Plants in V.N. Sukachev Institute of Forest

Abstract

Aim. The aim of the article is to find out the karyological features and conduct molecular and cytogenetic analysis on tree plants for biological diversity studies, solve problems of taxonomics, evolutionary and population genetics. Methods. Classic methods with acetohematoxylin staining of slides and new method of fluorescent in situ hybridization (FISH) had been used. Results . More than 250 populations and provenances of representatives of different genera of gymnosperms from the families Pinaceae, Cupressaceae, Ephedraceae and tree angiosperms from the families Rosaceae, Aceraceae, Polygonaceae, Nitrariaceae, Rhamnaceae, Fabaceae, Ericaceae were studied. Investigations had been conducted in natural populations and during the introduction, in optimal and extreme conditions, in disturbed ecosystems, botanical gardens and parks; in addition, various intraspecific forms and unique trees had been studied. The variability of chromosome numbers and a wide range of chromosomal mutations had been revealed. Use of fluorescence in situ hybridization (FISH) with the 45S and 5S ribosomal RNA gene probes and DAPI staining allowed to identify of homologous chromosome pairs in the karyotypes of conifers and to facilitate the comparative karyotype analysis of those species. Analysis of the chromosome numbers of woody angiosperms showed a significant role of polyploidy in their evolution. Conclusions. The studies on karyotypes in tree species showed their diversity, variability of chromosome numbers, higher level of chromosomal anomalies and their wide spectrum in extreme conditions, under introduction and also in cultivars and abnormal form of trees. The use of molecular cytogenetic markers made it possible to obtain new information on the structure of conifer chromosomes. The role of polyploidy in the evolution of woody angiosperms was shown.