Aspectos ecofisiológicos da germinação de sementes de arapiraca (Acacia farnesiana (L.) Wild.).

Abstract

Ecophysiological aspects of Arapiraca (Acacia farnesiana (L.) Wild.) seed germination. The germination process is affected by a series of intrinsic and extrinsic conditions such as humidity, temperature, light and oxygen. Studies about the ecophysiologic needs for germination in species are important for the knowledge about their biology. This study had the objective of determining the ideal temperature for the arapiraca seed germination and verifying the effect of hydric and salt stresses in the germination of these seeds. The experiments were conducted in the Plant Physiology Laboratory in the Health and Rural Technology Center in the Federal University of Campina Grande, Patos (PB). Temperatures of 20, 25, 30 and 35 °C were tested, distributed in totally casualized delineation with 4 repetitions and 25 seeds each. The substrate was moistened with 12 mL of distilled water. The seed germination in solutions of Poly (ethylene-glycol) (PEG-6000) and Sodium Chloride (NaCI) in eight osmotic potentials (0, -0,3; -0,6; -0,9; -1,2; -1,5; -1,8 e -2,1 MPa) were evaluated to stimulate hydric and salt stresses, respectively. The treatments were distributed in 2x8 factorial scheme in a totally casualized delineation, in 4 repetitions of 25 seeds each. The arapiraca seeds presented a wide range of temperature for germination, varying from 20 to 35 °C. This species demonstrated to be tolerant to hydric stress during the germination, but not to the salt stress.