Application of sequential selections in the selection of table carrots for resistance to <i>Fusarium sp.</i> and <i>Alternaria sp.</i>

Abstract

Relevance. Research is devoted to increasing the horizontal, polygenic resistance of table carrots of the Surazhevskaya variety to Fusarium sp. and Alternaria sp. infections. The aim of the research was to conduct sequential (at different stages of development) and multiple (over several reproductive generations) individual selections of table carrot plants resistant to a complex of pathogens using traditional phytopathological methods.Methods. The research was carried out in 2011–2019 in the Department of breeding and seed production in the laboratory of root crops and onions of the All-Russian Scientific Research Institute of Vegetable Growing — Branch of the FSBSI Federal Scientific Vegetable Center. The source material for research was a variety of carrots in the Surazhevskaya dining room, obtained in 2006 from the Flakke variety type. Assessment for resistance to Fusarium sp. and Alternaria sp. it was performed in the field, on two artificial infectious sites and in the laboratory in accordance with the methods. The correspondence (significance of differences) between the compared series (families) in the frequency distribution of the corresponding average scores of disease manifestations was assessed using the χ 2 criterion.Results. With each subsequent selection cycle, not only did the number of relatively resistant plants increase, but the average score of the lesion also decreased. As a result of four consecutive selection cycles at different stages of ontogenesis and in three nurseries with natural and artificial infection, the selection population changed in terms of resistance to Fusarium sp. and Alternaria sp. It is advisable to assess susceptibility to pathogenic flora in parallel on the natural and infectious backgrounds. Field assessment and selection of carrot plants should be carried out at different periods of the two-year development cycle, as well as during the storage of Queen root crops.

Assessment of the resistance of varieties and collection samples of flax to fusarium wilt

“…With severe damage to crops, fiber yield can decrease by 90-97%; seed yield by 43-65%. With severe damage to crops, a complete loss of seed yields is possible [6,7,8]. A pure culture of the pathogen was isolated by sowing plant residues with signs of fungal plaque on an agarized nutrient medium.…”