Screening of genetically diverse linear beetroot material for resistance to Pseudomonas syringae pv. aptata at different stages of plant development (sporophyte, gametophyte)

Relevance. The most important direction in the breeding of beetroot is the production of competitive domestic industrial hybrids based on CMS, for which it is necessary to create a fund of parent lines with a complex of economically significant traits and resistance to diseases. Recently, the harmfulness of bacterioses, including those caused by the pest Pseudomonas syringae pv. aptata (Psa), has been increasing in table beet crops, which determines the need to study the resistance of breeding material to bacteriosis at different stages of development. The aim of the research. To screen the linear and inbred beetroot material for resistance to Pseudomonas siringae aptata and identify the most valuable forms from them for the creation of bacteriosis-resistant hybrids. Materials and methods. Objects of research: collection isolate of Pseudomonas syringae pv. aptata (Psa 1-21); root crops, leaves, and populations of pollen grains of plant lines and inbred descendants of beetroot. The methods of phytopathology and gametic breeding were used in the work, artificial infection of the sporophyte and gametophyte was carried out with an aqueous suspension or liquid culture of Psa, according to the results of which the samples were ranked according to Results. Screening of linear and inbred beetroot material for resistance to Psa at different stages of ontogenesis (sporophyte, gametophyte) was carried out. It has been established that the sporophytic resistance of beet genotypes contrasting in resistance to Psa is determined by the level of organ-specific resistance. An inverse relationship has been revealed between the stability of the sporophyte and changes in the functional parameters of the microgametophyte, while it is advisable to use the stress tolerance coefficient (Ks) as a criterion fo2 r microgametophyte resistance, which is more associated with the damage score of root crops (R =0,66). It is recommended to use an aqueous suspension of the bacterium in two concentrations as a selective agent in the ranking of table beet samples for resistance to Psa. As a result of immunological screening, two breeding lines and four promising inbred offspring were selected and included in the breeding process, characterized by the resistance of the sporophyte and gametophyte to bacteriosis and a complex of breeding-valuable and economically significant traits.