Biopriming de sementes alivia o efeito do estresse salino na soja

Abstract

Salt stress is a concerning condition as it negatively affects seed germination and the performance of plants such as soybean. Seed conditioning with bioinputs biopriming) is a promising solution to this environmental problem. We aimed to evaluate the potential of isolated or combined biopriming of microalgae and different microorganisms in alleviating the stressful effect of salinity on soybean. The seeds were subjected to six biopriming: control (without biopriming), microalgae Parachlorella sp., Bacillus subtilis, Trichoderma harzianum, Parachlorella sp. + B. subtilis, and Parachlorella sp. + T. harzianum. Subsequently, the seeds were subjected to two conditions: i) control (0.0 MPa) and ii) saline stress induced by NaCl (-0.8 MPa). Germination and photochemical indicators, and seedling performance were evaluated. Salinity impaired root protrusion and seed physiology, resulting in a higher percentage of abnormal seedlings, making it a stressful condition. However, biopriming alleviated the negative effects of salinity, especially with T. harzianum, Parachlorella sp. + B. subtilis, and Parachlorella sp. + T. harzianum, resulting in higher germination indicators and normal seedlings. All biopriming, especially the combined ones, contributed to the reduction of non-photochemical quenching , favoring the maximum yield of photosystem II. We observed shorter lengths, and lower fresh and dry masses of seedlings under saline conditions without biopriming, whereas those with Parachlorella sp. + B. subtilis and Parachlorella sp. + T. harzianum showed higher values. Seed biopriming, especially with the combination of the microalgae Parachlorella sp. with B. subtilis or T. harzianum, alleviated the stressful effects of salinity.