Contribution à la connaissance de quelques facteurs agissant sur la germination des graines de Cynanchum acutum L.

Abstract

In order to study the effect of some abiotic factors on the germination of the species Cynanchum acutum L, the germinatif behavior of seeds of this adventitious collected of two sources (ex-ITAS and goussa) was evaluated through various degrees of temperature (5, 10, 15, 20, 25, 30, 35 and 40C), under the effect of salt 4types (NaCl, Na2 So4, CaCl2 and MgCl2) with 6 amounts (40;80;160;200 and 240 mmol/l), under the effect of four various sources of water of drainage, under hydrous stress with (0,2, 0,6, 1,2 and 1,6MPa), and the depths of semi (0, 5, 10, 15, 20 and 25cm). La response of seeds opposite the factors studied varies between the two sources and according to the nature and the intensity of the studied factor. The optimal temperature of germination was 30C° the species tolerates the concentrations moderate of salt 80 mmol/l, salts most harmful are NaCl, Na2 So4 and CaCl2.This species is strongly tolerant with the dryness, the seeds can germinated under a stress of 1,6 MPa. The rate of germination under the effect the depth is significant, higher à30% for all the depths tested