Desenvolvimento e aplicação de tecnologias em sementes arbóreas nativas da caatinga

Abstract

Rapid tests that allow the assessment of physiological potential are essential parameters for quality seed and seedling production programs. In chapter 1, the parameters of a method for evaluating the vigor of seeds of Myracrodruon urundeuva, Cenostigma pyramidale and Amburana cearensis seeds were established through the analysis of ethanol production, measured with a modified ethylometer. The ethanol test proved to be fast and accurate, allowing batch differentiation, as well as germination and electrical conductivity tests. In chapter 2, the combined application of physiological and biochemical tests was evaluated to determine the vigor of seeds of Anadenanthera colubrina, Pityrocarpa moniliformis, and Mimosa tenuiflora. The lots were evaluated for water content, germination and vigor (first count, electrical conductivity and ethanol test) with the measurement of Alcoholic Dehydrogenase (ADH) activity. The tests applied were efficient to identify the physiological quality of A. colubrina, P. moniliformis and M. tenuiflora seeds, contributing to the groupings of the verified crops. In chapter 3, the potential of ultrasound as a pre-sowing treatment capable of better expressing the vigor of native seed lots was evaluated. Pityrocarpa moniliformis and Mimosa tenuiflora seeds were immersed in distilled water and subjected to an ultrasonic pulse of 10 seconds with powers of 20W, 40W and 60W. The ultrasonic conditioning was able to significantly increase the germination and vigor of seeds, which also affected an expressive length of the seedlings.