Estimation of efficiency of recurrent selection on the field artificial infectious background in creating of red clover breeding material resistant to root rots

The results are reflected of research work on the evaluation of previously created hybrid material of red clover (Trifolium pratense L.), which passed a selection study on a field artificial Fusarium background in compare with initial forms without selection and standard variety Dymkovsky. For improving objectivity of the assessment, a field infection background was created based on a mixture of local strains of Fusarium spp. (F. oxysporum + F. avenaceum + F. heterosporum). The efficiency of formation of a disease-resistant breeding material by the method of recurrent biotypic selection was analyzed on the most significant economic and biological characteristics: winter hardiness; plant height; dry mass and seed productivity; disease resistance. Information on agrometeorological conditions in the years of research was provided. According to the results of the study, a high winter hardiness of breeding populations was found in various conditions of the autumn-winter periods. The tendency was noted of increasing in forage and seed productivity in hybrids that have been selected on an infectious background in comparison with the initial forms; their lower susceptibility to root rot in the second year of life was established. For further breeding work, three prospective root rot-resistant populations have been selected: GPF-64-2 — with significantly higher dry matter yield relative to standard Dymkovsky by year of use; GPF-60-2 — with seed yield at the level of the standard and the excess of initial form by 87.5%; GPF-63-2 — with the least degree of damage to the root system in comparison with initial form and standard.