Formation of phytopathogenic complex Rosa in phytocenosis cultures with varietal variability of resistance indicators against Sphaerotheca pannosa var. rosae and Diplocarpon rosae
A plant organism is the basis of urban ecosystem, the species diversity of flowering and ornamental plants is the formation factor of the microbiocenosis structure, its quantitative and qualitative composition. The aim of the work is to establish the influence of varietal variability of resistance indicators to Sphaerotheca pannosa var. rosae and Diplocarpon rosae on the Rosa genus plants for the formation of phytopathogenic complex in phytocenosis cultures.
To achieve this goal we performed the following tasks: to select Rosa cultivars for biocontrol of phytopathological complex formation in urbanized ecosystems on the basis of evaluation of immunological reaction of collection samples of these plants in natural infectious background.
Scientific novelty is determined by the following research results: there were studied ecological and biological bases of conducting phytomeliorative measures and selection of roses assortment for formation of resistant groups of flower-ornamental plants of phytocenosis cultures; as a result of immunological evaluation of roses varieties, there was determined a list of varieties that are the selection factors of highly virulent pathotypes of fungi Sphaerotheca pannosa Lev var. rosae Woron. and Diplocarpon rosae F.A.Wolf for biocontrol of phytopathogenic mycobiota.
During the years of research, a stable (As ≥ 60.1%) manifestation of the resistance indicator afainst Diplocarpon rosae was found in 46 cultivars (67.6%), and against Sphaerotheca pannosa var. rosae in 43 (63.3%)-collection cultivars of the Rosa genus. In regional collections of roses in terms of resistance against Sphaerotheca pannosa var. rosae, Diplocarpon rosae the samples were represented mainly by practically resistant forms (48 ± 5.2%). Practical significance for biocontrol of phytopathogens in urban ecosystems and as a source of resistance for assortment fitting and selection, for agroecology as the selection factor of highly virulent pathotypes of the fungus Sphaerotheca pannosa var. rosae have 20 cultivars of tea-hybrid roses, 12-of twisting roses, 3-of floribunda roses, 4-of English roses, as for Diplocarpon rosae-there are 27 varieties from the group of tea-hybrid roses, 4-twisting roses, 2-floribunda roses, 4-English roses.