The Effect of Priming with Different Levels of Chitosan on Physiological and Biochemical Traits in French Bean (Phaseolus vulgaris L.) Under Salinity Stress

Priming prepares the seeds physiologically and biochemically for germination before being placed in their bed and exposed to the salinity stress. In order to investigate the effect of different levels of chitosan on physiological and biochemical traits in French bean (Phaseolus vulgaris L. CV. Sadri) under salinity stress, a factorial experiment was conducted based on a completely randomized design with four replications at the University of Mohaghegh Ardabili in 2021. Factors included four salinity levels (0, 50, 100 and 150 mM) and four chitosan levels (0, 0.25, 0.50 and 0.75% by weight-volume). The results showed that salinity stress decreased germination percentage (GP) and increased mean germination time (MGT) and residual dry weight (RDW). Chitosan reduced the effect of salinity and improved GP and Seedling Moisture Percentage (SMP). With increasing salinity, seed reserves utilization rate (SRUR), seed reserve utilization efficiency (SRUE) and deduction of used seed reserves (DUSR) decreased. The highest and the lowest of SRUR, DUSR and SR were obtained from the application of salinity levels of 50 and 150 Mm, respectively. The amount of SRUR, SRUE and DUSR in 0.75 chitosan priming was higher about 10.4, 9.6 and 7.2%, respectively, compared to the control treatment (priming with distilled water). SRUE and SR reduction was about 13.4 and 8.3%, respectively compared to the control without salinity. Also, the amount of Protein and Phytin in pretreatment with 0.75% chitosan and 0 mM salinity showed an increase about 30% and 47% compared to the control, respectively. In general, seed pretreatment with appropriate concentrations of chitosan especially 0.75% chitosan improves growth and reduces the adverse effects of salinity on the bean plant.