The relationship between resistance of cowpea (Vigna unguiculata) accessions to low temperatures and diseases in Siberia

Abstract

The aim of the study is to investigate the relationship between the cold tolerance of Vigna samples and their susceptibility to pathogenic micromycetes. Ten Vigna unguiculata samples were used. Pollen viability in vitro was assessed in a 20 % PEG 6000 solution at 25 °C for 3 hours (control) and at 6 °C for 24 hours (cold tolerance assessment). Seed germination under low temperatures was evaluated by germinating seeds on filter paper at 10, 12, and 25 °C (control), as well as in soil at a constant 25 °C and under a regime of 10 °C for 10 days followed by 25 °C. Root system adaptability to low temperatures was determined by growth rate under a 25 °C → 14 °C regime and by the ratio of growth rates at low versus optimal temperatures. Correlations between traits were analyzed using SPSS and Excel. The study revealed significant differences among Vigna samples in cold tolerance and susceptibility to pathogenic micromycetes. A significant negative correlation was found between pollen cold tolerance (0—97.9 %) and seed infection rate, as well as between seed germination at low temperature (0—77.7 %) and infection percentage. Pollen cold tolerance showed a significant positive correlation with seed germination on filter paper at 10 °C (r = 0.787; p < 0.01) and with overall seed cold tolerance (r = 0.757; p < 0.05). Samples with high germination after recovery from cold exposure exhibited lower rates of seed rot. Furthermore, the study identified correlations among the cold tolerance of pollen, seeds, and the root system. The Zinder and Fakir varieties demonstrated the best overall performance, combining high cold tolerance with low seed rot rates. This research provides a theoretical basis for the selection of Vigna cultivars for stress resistance.