Evaluation of the resistance of medicago breeding samples to the action of abiotic stressors at the early stages of ontogenesis

Federal Williams Research Center of Forage Production & Agroecology, 1 building, Scientific town, Lobnya, Moscow region, 141055, Russia

^* Corresponding author: dumacheva63@mail.ru

Abstract

New knowledge was obtained about the relationship between the parameters of photosynthesis, transpiration and dark respiration in alfalfa varieties of various ecological and geographical origin at the early stages of ontogenesis, depending on the intensity of abiotic stressors: salinity conditions (0.3 M NaCl) and various intensity of photosynthetically active radiation (from 0 to 1500 mol*m⁻² s⁻¹). Purpose of the work: assessment of the potential resistance of alfalfa varieties and breeding samples to abiotic stressors for breeding for adaptability. To determine the parameters of gas exchange of cotyledon leaves of alfalfa varieties, a portable system for measuring plant gas exchange LI-6800, LI-COR, USA was used. The results of a two-way ANOVA analysis of the influence of the salinity factor and illumination conditions on the resulting signs of gas exchange parameters showed that the proportion of the influence of the genotype of breeding samples on the studied effective signs associated with the operation of the photosynthetic apparatus (the intensity of CO₂ assimilation and the intercellular concentration of CO₂) ranged from 7.25 to 21.35%; associated with water exchange parameters (transpiration and stomatal conductivity for H₂O) varied from 18.80 to 19.84%. Selected breeding samples of alfalfa with high resistance of the photosynthetic apparatus to abiotic stressors.