Аnalysis of the combinational ability of spring soft wheat hybrids according to the resistance to leaf Septoria and plant productivity

Abstract

In increasing the efficiency of breeding work on the creation of spring soft wheat varieties information about the combinational ability of the source material is of great importance. In 2021-2022 in the conditions of the Kirov region the general and specific combinational ability of 8 varieties and 28 hybrids of the second generation of spring soft wheat was studied according to the degree of leaf septoria damage, grain size and yield. The studies were carried out under natural conditions of development on the leaves of Parastagonospora nodorum as the molecular-genetic affiliation of the causative agent of septoria blotch to this species had been established. As the result of the conducted studies, for further breeding work there were selected 14 resistant F2 hybrids characterized by average values of the resistance index and a slow growth of infection. According to the complex of selective-immunological traits, the hybrid Rosinka 2 × Tertsiya was isolated, combining resistance to septoria with a high mass of 1000 seeds (41.6 g) and yield (410.0 g/m2). The tolerant hybrid of the Stepnaya 50 × Daria was particularly noted, which with a high degree of damage (34.2 %) formed a large grain (42.6 g) and the maximum yield for the experiment (411.1 g/m2). The conducted dispersion analysis of the data obtained has shown that the spring wheat variety Tertsiya (Russia) has a significantly high overall combinational ability (ОСА) by all the studied traits and can be their source in breeding programs. Moreover, the Epos variety (Germany) is the most effective as a source of resistance to septoria; Egisar 29, Niva 2, Stepnaya 50 and Rosinka 2 (Russia) are sources of grain size; Daria (Belarus) is a source of high yield. As the result of the analysis of the dominance index in most of the studied hybrids, the additive effect of genes on the manifestation of resistance to leaf septoria and seeds size was found. The effect of heterosis by disease resistance was observed in 21.4 %, by weight of 1000 seeds – in 42.9 % and by productivity – in 50.0 % of the studied hybrid combinations.