Indução de tolerância ao estresse salino durante a germinação de sementes de Physalis peruviana L.

Abstract

The osmotic conditioning is a technique used to accelerate and standardize the germination. Positive effects of the osmotic conditioning become evident under stress situations. In this manner, this technique can be used to give seeds resistance to stress, improving their performance under adverse conditions, such as, the presence of salts in the soaking solution of the seeds during germination. The current work had as objective to evaluate the effect of the osmotic conditioning on the induction of tolerance to the saline stress during the germination of Physalis peruviana seeds. It was used the completely randomized design on 5x5 factorial scheme (four osmotic potentials and control of dry seeds during five saline levels to germination). The work was conducted at the Analysis Laboratory of Seeds and Seedlings of the Federal University of Campina Grande. The seeds were conditioned in PEG 6000 solution adjusted to potentials of -0.2; -0.4; -0.6 and -0.8 MPa, at 25 ° C for a period of 120 hours. To evaluate the conditioning effect, germination test was performed under saline stress at the electrical conductivities of 0,3 (control); 1.5; 3.0; 4.5 and 6.0 dS.m-1 in BOD regulated at 25 ºC, evaluating the percentage of germination, first germination count, germination speed index, mean germination time and germination speed average. The obtained data were submitted to variance analysis and polynomial regression represented in response surface graphs. The osmoconditioning at the osmotic potential of -0,2 MPa and -0.4 MPa promoted better results for the germination variables until the electrical conductivity of 1.5 dSm.-1.