Results of symbiotic breeding of alfalfa

Abstract

The results of the studies on the effectiveness of alfalfa symbiosis varieties created by different methods are presented. Some peculiarities of plant-rhizobial interactions are identified. When alfalfa was grown in low- and near-neutral soils (pH 5.1-6.0), the highest increase in dry matter yield was achieved by pre-sowing inoculation with the CXM 412b strain, and on strongly and moderately acidic soils (pH 4.1-5.0) by the CXM 404b strain. In the year of sowing, the efficiency of symbiosis was at least 25%, and the yield reduction to the control level occurred during 3-4 years of use. Strain СХМ 404b has the unique ability to increase the seed productivity of different varieties under different growing conditions by 23-56%, other strains - by 3-32%. It was found that the productivity of variety microbial systems is mainly determined by the strain of nodule bacteria (the effect of inoculation was 60-62%). No relationship between the yield of the aboveground biomass and its crude protein content was found. The correlation coefficients obtained in the different field experiments were -0.41 ± 0.34 to 0.26 ± 0.39. Pre-sowing inoculation with highly active rhizobia strains of alfalfa variegated seeds of Selena, Agnia, Taisia, created using the methods of conjugate symbiotic breeding, increased the yield in the year of sowing by 26-35% in dry matter and by 44-56% in seeds. The yield of Vega 87, Lugovaya 67, Pastbishnaya 88, and Nakhodka varieties created by traditional methods increased by 3-20% in dry matter and by 23-29% in seeds. Pre-sowing inoculation with active rhizobia strains of alfalfa cultivars created by symbiotic breeding methods increased the yield in the first year of use by 46-128% in plots where alfalfa was not grown before and by 32-35% in the crop rotation with high alfalfa crop saturation.