Effect of priming and different types of drying on the physiological quality of Urochloa ruziziensis seeds

Abstract

Seed vigor is one of the main limitations to meet the demanding forage market. In order to boost the productive potential and provide the satisfactory development of quality seeds and seedlings, it is necessary to develop techniques that provide quality and high productivity. With the Urochloa genus stands out in the seed production and quality, this study aimed to evaluate the effect of seed priming with sodium nitroprusside and to define the best drying method that allows the maintenance of the changes of this treatment in Urochloa ruziziensis seeds. The seeds were conditioned in sodium nitroprusside solution, as a nitric oxide donor, for 42 hours and later submitted to the following procedures: no drying, initial reduction of water content, thermal shock, slow and fast drying. The design was completely randomized, with ten treatments and four replications. Water content, germination, emergence and biochemical evaluations were performed. As results, it was observed that all drying methods evaluated reduced the water content of the seeds to 12%, recommended range for storage, with the exception of the treatment without drying that presented 30%. Regarding germination parameters, the treatment of initial reduction and quick drying obtained the best performance in germination and emergence. Moreover, the types of drying presented high rate of enzymatic activity of the antioxidant system, thus helping in the maintenance of redox homeostasis. According to the enzymatic activity and germination rates, it suggests that the rapid drying method after priming with nitric oxide is the best method for Urochloa ruziziensis.

Antioxidant Defenses Determine the Maturation and Physiological Quality of in Vitro Euterpe Edulis Martius Seeds

“…The increased activity of metabolic and respiratory processes intensi es the production of ROS, which triggers the cell's antioxidant defenses to maintain homeostasis. The accumulation of ROS and the damage they in ict are determined by the e ciency of the antioxidant system, which preserves the conformation of proteins, lipids, and DNA (Melo et al, 2021). Mitochondria and peroxisomes are the main organelles responsible for intracellular ROS production.…”

“…CAT is effective at neutralizing high concentrations of H 2 O 2 and maintaining them within controlled levels (Melo et al, 2021). In seeds of A. angustifolia, the genes APX and SMP (encoding SEED MATURATION PROTEIN) showed decreased expression in the cotyledons, the CAT gene was more expressed in the embryonic axes, while GPX (GLUTATHIONE PEROXIDASE) and SOD genes exhibited no signi cant difference after dehydration (Gasparin et al, 2021).…”

“…APX plays a key role in the ascorbate-glutathione cycle and the elimination of H 2 O 2 from plant cells. This enzyme is important for cell wall biosynthesis, cell growth, differentiation, and development, in addition to its involvement in stress responses (Melo et al, 2021). APX reduces H 2 O 2 to H 2 O by oxidizing ascorbic acid and dehydroascorbate (Obroucheva et al, 2016).…”