Yield-related morphometric indicators of vegetable bean plants after gamma irradiation of seeds

Relevance. Radiation mutagenesis has shown its effectiveness in expanding the genetic diversity of breeding material for a number of crops. A number of radiobiological studies are required in order to use γ-radiation to increase the variability of quantitative traits of vegetable beans. Objective. To study the yield-related morphometric parameters, symbiotic activity and pollen viability of vegetable beans after γ-irradiation of seeds (at doses of 25, 50 and 75 Gy) to develop a radiation mutagenesis protocol. Materials and Methods. The objects of the study were two varieties of vegetable bean bred by Omsk State Agrarian University. The seeds were γ-irradiated (source – 60Co) at doses of 25, 50 and 75 Gy (dose rate 60 Gy/hour). M1 plants were grown in the field of the Educational and Experimental Farm of Omsk State Agrarian University. Non-irradiated M2 seeds of variety Marusya (obtained from plants irradiated at a dose of 50 Gy) were also sown in the field. Yield- associated morphometric parameters, symbiotic activity, and pollen viability were assessed. Statistical analysis was performed using nonparametric methods in R (ver. 4.3.3). Results. Gamma irradiation of seeds of both studied varieties of vegetable beans adversely affected some yield-related morphometric parameters of M1 plants (number of seeds in a pod, number of seeds per plant and seed weight). Unlike the Marusya variety, irradiation of seeds of the Pamyati Ryzhkovoy variety adversely affected the rate of flowering, pod formation and technical maturity, regardless of the dose. In Marusya plants, after seed irradiation at a dose of 50 Gy, earlier flowering and pod formation were observed compared to the control, as well as more pronounced development of nodules. Male sterility was detected in plants in the 75 Gy irradiation group. Irradiation of seeds of both studied varieties led to an increase in the mass fraction of calcium and protein in green beans of the M1 generation. Unlike M1, statistically significantly higher plant height, number of pods and seeds per plant and seed weight per plant were detected in M2 plants of the Marusya variety. Conclusion. Seed irradiation has a negative effect on the productivity parameters of plants in the M1 generation and a positive effect on M2. In field conditions, M2 plants of the Marusya variety showed better yields compared to the parent variety and will be used in further selection. The effect of γ-irradiation of vegetable bean seeds on the development of nodules has been shown for the first time. The most pronounced stimulating effect was noted for the dose of 50 Gy in the Marusya variety. For the radiation mutagenesis protocol of vegetable beans, a dose of 50 Gy is recommended.