Morphometric parameters of plants in bean populations M1 and M2 after gamma irradiation of beans

Breeding new productive, tolerant bean varieties remains an urgent issue to meet market demand for high-quality plant protein. One powerful tool for increasing the genetic diversity of breeding material is radiation mutagenesis, the effectiveness of which depends on the selected radiation dose. The purpose of the current study was to identify changes in the morphometric parameters of plants, the development of nodules and the germination of bean pollen after γirradiation of seeds at doses of 25, 50 and 75 Gy in order to select the optimal dose for radiation mutagenesis. There have been sown two new common bean varieties Omsky Rubin and L’dinka developed by the Omsk SAU, γ-irradiated at doses of 25, 50 and 75 Gy in three replicates (populations M1) and the beans of the second generation of the variety Omsky Rubin (population M2), irradiated at a dose of 50 Gy in order to estimate morphometric parameters, such as plant height, pod length, attachment of a lower pod, distance from a lower pod tip to soil, number of pods per plant, number of beans per pod, number of beans per plant, weight of beans per plant; length of development phases, number and weight of nodules, content of iron, zinc, calcium and protein, as well as to evaluate the germination of pollen grains. Statistical analysis was performed using the Kruskal–Wallis H test with Dunn’s multiple comparison test or the Mann–Whitney U test. There has been found that seed irradiation negatively affects morphometric parameters, such as pod length, number of beans per pod, number of beans per plant, and weight of beans; the length of development phases of the M1 population, and nodule development of the variety Omsky Rubin, while it had a positive effect on the number and weight of small nodules of the variety L’dinka. M2 plants of the variety Omsky Rubin, with higher indicators of productivity (number of pods, weight of beans) compared to the parent variety, will be recommended for breeding. For the radiation mutagenesis protocol of common beans there has been recommended a dose of 50 Gy.