Efficiency of Gibberellic Acid (GA3) priming on soybean seed imbibition and seedling performance

Abstract

Soybean is a plant that has oil as the main component, thus easily causing the seeds deteriorate. Therefore, it is difficult to preserve them over a season to use as good quality seeds. This research focuses on finding a method for improving the quality of soybean seeds that have been stored across seasons by using the seed priming technique with Gibberellic acid (GA3) at various concentrations together with PEG6000 at a water potential -1.2 MPa in three varieties of soybean: Chiang Mai 60 (CM 60), Chiang Mai 2 (CM 2) and, SJ 5, were planted in the dry season and stored for 6 months. The research operation consists of three experimental. First, to study the effect of priming on seed quality. Testing was carried out on three varieties: CM 60, CM 2, and SJ 5, were planted in the dry season and stored for 6 months. They were primed with GA3 solution at concentrations of 10, 20 and 30 ppm with PEG6000 at a water potential -1.2 MPa for 5 hours. The result show that seed priming with GA3 at a concentration of 20 ppm with PEG6000 at a water potential -1.2 MPa for a period of 5 hours is suitable for CM 60 and CM 2 varieties and 30 ppm in SJ 5 variety. The priming resulted in increased seed germination, field emergence and seed vigor compared to unprimed seeds. It was also found that Priming reduces the germination time of seeds, causing them to germinate faster. Second, study of water absorption rate. and the appropriate time period for priming. The seeds of all three varieties were soaked in three types of solutions: water, gibberellic acid (GA3) solution at a concentration of 30 ppm, and gibberellic acid (GA3) solution at a concentration of 30 ppm. + PEG6000 at a water potential -1.2 MPa of 12 hours. The water uptake rate of soybean seeds in Phase I occurred rapidly during 1-3 hours after soaking. After that, the seeds absorbed more water at a reduced rate and began to enter Phase II in the 5th-6th hour in the water solution. But in the GA3 + PEG6000 solution at a water potential -1.2 MPa, the entry into Phase II occurred between the 6th and 8th hours. Soaking the seeds in the GA3 solution together with PEG6000 at a water potential -1.2 MPa for 5 hours caused the seeds to have Germination increased compared to unprimed seeds. The last one, the effects on enzyme activity: GA3 solution at a concentration of 30 ppm promoted enzyme activity, with β-amylase having the highest response.