Saline stress and temperatures on germination and vigor of Piptadenia moniliformis Benth. seeds

The knowledge concerning the physiology of germination in saline areas may contribute to the development of more efficient cultural practices and adequate choice of planting areas. Thus, the objective of this study was to evaluate the effects of saline and temperature stress on germination and vigor of Piptadenia moniliformis (a species known in Brazil as catanduva) seeds. The treatments were distributed according to a completely randomized design in accordance with a 3 x 6 factorial arrangement (temperature x osmotic potential), with four replicates of 25 seeds each. The seeds were put to germinate at constant temperatures of 25, 30, and 35 degrees C on paper towel moistened in distilled water (0.0) and NaCl solutions at 0.2, 0.4, 0.6, 0.8 and 1.0 MPa. The results were evaluated in terms of germination percentage and germination speed index, seedling (root and shoot) length, and total dry matter. P. moniliformis seeds were able to germinate under temperatures of 25 and 30 degrees C and tolerate osmotic potentials of up to -0.6 MPa; from this point on, there is progressive decrease in the physiological quality of seedlings.