Abstracts

Diversity of the Vegetation

The collection of food and medicinal crops has been worked out at the Institute of Cytology and Genetics in a short period of time. The collection includes 8,000 accessions of 113 species belonging to 25 families and is collected in different areas of Siberia. The research of the collection is carried out under permanent field conditions. Biological productivity, vegetation period, resistance to environmental stress and biochemical composition are being studied. In some cases, the cytological and isozyme assay is also performed. A great bulk of data is collected and computer database is worked out. It permits to determine inter- and intraspecies biodiversity of Siberian plants. Two examples are demonstrated below.

(1) Study of chromosome sets in 46 cultivars and 161 wild accessions of smooth brome-grass Bromus (Bromopsis) inermis Leyss. of different geographical origin has shown that octoploid forms are expanded at the territory of the former Soviet Union. The octoploid plants (56 chromosomes) formed 72% and the tetraploid plants (28 chromosomes) formed 28% of the analysed ecotypes. Total amount of octoploid brome-grass forms increased in the direction from the South to the North. The largest percent of octoploids was registered in the latitude of 50o - 70o North interval. On the contrary, the percentage of tetraploid forms was increased in the South. Polymorphism on morphometric and economic traits of smooth brome-grass on different ploidy levels is being studied in the collection.

(2) Isozyme analysis of two enzyme ADH and MDH systems has been carried out on 11 populations of Amaranthus caudatus and 6 populations of Amaranthus cruentus. In the experiments the single anode zone of ADH was registered. Three types of patterns were detected in this zone: (a) fast one-band pattern of electrophoretic mobility, FF phenotype; (b) slow one-band pattern, SS phenotype; (c) three-bands hybrid pattern, FS phenotype. These types of isozyme patterns are typical of dimeric enzyme controlled by the single locus Adh with two alleles (Adh1-F and Adh1-S). NAD-dependent MDH has two anode zones of enzymatic activity: fast and slow ones. Fast migrating bands are indistinct and, therefore, it is impossible to identify the band pattern. Three types of patterns were noted in the slow zone: one-band (NN/FF phenotype), two-band (NN/SS phenotype), and three-band pattern (NN/FS phenotype). We suppose that the products of two loci controlling NAD-dependent MDH, namely monomorphic Mdh1 and polymorphic Mdh2 enzyme products with Mdh2-F and Mdh2-S alleles were detected in this zone. The study of enzymatic polymorphism has shown that the degree of genetic variability is also necessary for species characterisation as well as the shape, size and flower morphology. It can be used for analysis of both intra- and interspecies diversity.

Note. Abstracts are published in author's edition

|Home Page| |English Part|

Go to Home