Phenotyping of guar accessions from the VIR collection under irrigation and artificial drought conditions in Volgograd Province

Background. Guar ( Cyamopsis tetragonoloba (L.) Taub.) is a newly introduced crop for southern regions of Russia. Guar gum, a component of guar seeds, is used in a number of sectors of the national economy, being strategically important for the gas and oil industry. Targeted introduction of guar requires better understanding of the crop’s adaptive potential, and more specifically, its responses to droughts typical for most of Russia’s southern areas. Material and methods. Guar accessions from the VIR collection were phenotyped at Volgograd Experiment Station of VIR in 2023–2024. The studied set was selected to represent the crop’s gene pool to the fullest extent possible. The same accessions were studied under drip irrigation and artificial drought conditions. The study was performed according to the guidelines developed at VIR. Statistica 13.3 software was used for statistical data processing. Results. Seed productivity was accepted as the main criterion to assess the plant’s adaptability to drought. On its basis, the studied set of accessions was differentiated into three groups: drought-tolerant, sensitive to drought, and neutral to water supply. The analyzed indicators manifested different degrees of variability under the conditions of irrigation and drought. The status revealed for the majority of accessions in the context of their responses to drought remained unchanged in both years of the study. Conclusion. The drip irrigation scheme used in 2023 (5 L per plant per week) turned out to be excessive for most accessions, while the one half as lower in 2024 (2.5 L per plant per week) appeared favorable for the accessions of all three groups. With optimal irrigation, a majority of guar accessions exhibited a tendency toward increased seed productivity, regardless of the group.