Germination behaviour of Tricholaena teneriffae, a perennial grass from arid and semi-arid zones

摘要

Tricholaena teneriffae is a xerophytic perennial herb that belongs to the Poaceae and has potential for use in ecological restoration programmes. To provide basic information for its conservation and reintroduction, the influence of environmental factors on seed germination was studied. Maximum germination was obtained at 25 degrees C, corresponding to the temperature that prevails during the mid-spring season in arid and semi-arid zones of Tunisia. Seeds incubated in polyethylene glycol (PEG) solutions exhibited significantly lower germination than control, especially when water potential fell below -0.6 MPa. The highest germination (80%) was obtained under control conditions without PEG, and increasing moisture stress progressively inhibited rate and percentage of germination, which was less than 5%.at -2 MPa. Seed germination was substantially delayed and reduced with an increase in NaCl to levels above 50 mM, but the percentage was not significantly reduced at low salinity (= 20 mM). T teneriffae is moderately salt tolerant at the germination stage.