Fruit growing
and viticulture of South Russia

Annotation

Adverse weather conditions promote the spreading of phytopathogenic microorganisms that in turn is the reason of thinner of gardens and uterine plantings. For satisfaction of needs for qualitative landing material it is necessary to use the rootstocks with high degree of resistance to an adverse effect of abiotic and biotic factors. The greatest economic danger has such widespread disease as an apple-tree scab. The purpose of work is screening on resistance to V. inaequalis of various rootstock's forms of an apple-tree under natural conditions of a garden for selection the most perspective forms on this sign. The objects of research are 72 rootstock's forms from a genetic collection of an apple-tree of Michurinsk Agricultural University. Microorganisms of Venturia inaequalis (Cocke) of Wint., Alternaria alternate (Fr.) Keissl. and a bacterium from the sort of Pseudo-monas, selected from the sick tissue of plants, were studied under the conditions of clear culture. The assessment of a phytosanitary condition of uterine plantings was carried out according to the standard techniques visually, and also using the microscope methods and by testing for existence of an infection. On the basis of phytosanitary evaluation of clonal rootstocks of apple plantations is revealed an associative type of lesion by microbiota with dominate of Venturia inaegualis (Cocke) Wint. The role in the pathogenesis of microorganisms belonging to the association is established. The stability of a population of clonal apple rootstocks to scab on the natural infectious background of hybrid garden is studied. The genetic differentiation of forms on this trait is revealed. It is shown that over 80% of the genotypes have a minor lesion by scab - to 2 points. Symptoms of lesion are not observed in 5 % of genotypes. These forms we recommended for breeding and production.