盐胁迫对獐茅生长及Na+和K+含量的影响

用含0～200mmol/L浓度的NaCl的Hoagland培养液处理獐茅幼苗,处理17 d后测定一些生理指标,结果表明獐茅的生长受NaCl抑制程度随浓度增加而增大,没观察到最适盐浓度,且叶片较根部对盐分更敏感;有机干重的比例增大表明有机物在渗透调节中的贡献随之增大.植株在加喷对盐腺向体外排盐有抑制作用的溶液-苯硫酸胆碱100mmol/L后,Na 、K 含量在叶片内增加,而在分泌物中的量降低,并表现出生长进一步受到抑制.X-ray微区分析结果表明獐茅可以将Na 区域化到盐腺细胞,以便将其分泌到体外.

Effects of Salt Stress on the Growth and Na+ and K+ Contents in Aeluropus littoralis var. sinensis Debeaux

After seedlings of Aeluropus littoralis var. sinensis Debeaux were treated with different NaCl concentrations (0-200 mmol/L) for 17 days, some physiological indexs were measured. With an increase in NaCl concentration, the growth of A. littoralis was inhibited gradually. There was no optimum salt concentration, and the shoots were more sensitive than the roots. The proportion of organic dry weight in total dry weight increased, which implies that the contribution of organic matter to osmotic adjustment increased with salinity. After being treated with the inhibitor--benzene-sulphuric acid choline which could inhibit the salt glands to secrete the salinity outside the body. The Na(+) and K(+) contents of leaves increased, while the amount of Na(+) and K(+) decreased in the secretion, and the growth was severely inhibited. After being treated with NaCl 100 mmol/L, the relative Na(+) contents in the cap cells and basal cells determined by X-ray microanalysis were from about one to more than triple those of the epidermis and mesophyllous cells, it shows that the salt glands could effectively collect Na(+) from other cells and secrete them outside the body to keep normal physiological function.