盐旱互作对不同生境盐地碱蓬种子萌发和幼苗生长的影响

研究了盐旱互作对潮间带和盐碱地生境盐地碱蓬棕色种子萌发、地上部生长和离子积累的影响。不同盐浓度预处理后,未萌发的种子风干后复水,其萌发率与对照相比没有降低,说明两种生境盐地碱蓬种子萌发期间都耐干湿交替。400mmol/LNaCl溶液浇灌的潮间带生境盐地碱蓬幼苗在第3次干旱处理后萎蔫幼苗的百分比高于盐碱地生境的,而复水后正常幼苗的百分比却相反。400mmol/LNaCl溶液处理下,第3次干旱处理复水后,盐碱地生境盐地碱蓬幼苗地上部离子含量(主要是Na+和Cl-)高于潮间带生境的。表明在干旱情况下,盐碱地生境盐地碱蓬幼苗能积累更多的无机离子,降低渗透势,提高根系吸收水分的能力。上述结果说明,盐碱地生境盐地碱蓬幼苗较潮间带生境盐地碱蓬幼苗更耐盐与干旱的交互作用。

The effects of salinity and drought interaction on seed germination and seedling growth of Suaeda salsa L. from different habitats

We investigated the effects of interactions of salinity and drought on germination of brown seeds, and growth and ion accumulation of seedlings grown from brown seeds of Suaeda salsa L. from an intertidal zone and a saline inland habitat. The dryness/moist rotation had no adverse effect on germination of dry seeds pretreated in different concentrations of NaCl for either population, indicating that seeds of both populations have a high tolerance of dryness/moist rotation. The percentage of wilting seedlings irrigated with 400 mmol/L NaCl in S. salsa from the intertidal zone was higher than that of the inland population under drought conditions at the third time of irrigation, but the opposite trend was found for the percentage of recovery of seedlings after wilting seedlings were supplied with fresh water again. Ion concentrations (mainly Na+ and Cl- ) in shoots of seedlings watered with 400 mmol/L NaCl in S. salsa from a saline inland habitat were higher than those of the inland population when the experiment was terminated which indicates that seedlings of S. salsa from the saline inland habitat can accumulate more ions to decrease their osmotic potential, to ensure water uptake, compared with S. salsa from the intertidal zone. The present results indicate that seedlings of S. salsa from a saline inland habitat are more tolerant to salinity and drought interactions than the intertidal population.