Interferência do Priming na qualidade de sementes de cevada

Abstract

The speed and uniformity of germination of the barley seeds are essential for the establishment of the seedlings, and priming is a technique that can favor the germination process. Thus, in this research the application of priming for barley seeds, BRS Cauê cultivar, was evaluated, as well as interference of priming in the physiological and sanitary parameters of the seeds, immediately after the application of this technique and during storage, and whether priming favors seed germination and vigor when associated with reduction water availability and temperature and in salinity condition. In the first stage, initially, was determined the water uptake kinetics by barley seeds, hydrated by immersion at 15 °C and 20 °C and, then the seeds were submitted to priming using distilled water (0 MPa) and polyethylene glycol (PEG 6000) solutions (-0.1, -0.2, -0.4, -0.6, -0.8, -1.0, -1.2 and -1.4 MPa). In the second stage, the interference of priming (water and PEG 6000 solutions -0.1, -0.2 and -0.4 MPa at 15 °C) was determined in the seeds germination and vigor and fungi incidence during six months storage. And in the third stage, the seeds were placed to germinate in adverse environmental conditions: low water availability (PEG -0.7 MPa); low temperatures (5 °C and 10 °C) and salinity (NaCl -0.7 MPa). It was possible to verify that the methods by immersion at 15 °C in water or PEG 6000 solutions -0.1; -0.2 and -0.4 MPa are considered more appropriate for priming of barley seeds. Priming allows significant increases in the seed germination speed and seedling emergence speed. The beneficial effects of procedure are maintained throughout the six months of storage under controlled environment conditions (17 °C and 50% relative humidity). The main fungi associated with barley seeds are Bipolaris sorokiniana, Alternaria alternata, Fusarium graminearum and Cladosporium spp.. In addition, priming preserves the quality of barley seeds when there is limitation of water availability and temperature and salinity, presenting increases in the germination speed and the length primary root of the seedling, especially in least vigorous seeds.