基质盐含量对2种槲栎幼苗生长及生理适应性的影响

为了比较北京槲栎和锐齿槲栎的耐盐性及其机理差异，以2种槲栎的2年生幼苗为材料，用1‰~4‰的不同浓度NaCl水溶液进行处理，研究不同盐含量条件下2种槲栎幼苗生长、生理适应性及k+、Na+离子分布。结果表明，随盐浓度的增加，2种槲栎的总叶面积及生物量显著降低，北京槲栎降低幅度达30%，而锐齿槲栎降低幅度达到50%以上，叶片质膜相对透性总体呈增大趋势，锐齿槲栎的增大幅度比北京槲栎高29%，锐齿槲栎叶片保护酶SOD、渗透调节物质脯氨酸和可溶性蛋白含量都显著低于北京槲栎。盐胁迫下2种槲栎根系吸收的K+离子多向茎叶中运输，而吸收的Na+离子多滞留在根系中，北京槲栎能维持稳定的K+离子含量在15 mg/g左右。由比较得知2种槲栎在基质盐浓度低于3‰时都具有一定的耐盐性，且北京槲栎耐盐能力优于锐齿槲栎。

The Effects of Salt Stress on Physiology Response and Seedling Growth of Two Q. aliena Varieties

The aims were to investigate the salt tolerance of Quercus aliena var. pekingensis and Quercus aliena var. acuteserrata, and compare their mechanism difference. The two-year old seedlings of Quercus aliena var. pekingensis and Quercus aliena. var. acuteserrata were studied under salt stress. The seedlings were treated with different concentrations of NaCl （1‰-4‰）. The growth, physiological response of seedlings and K＋, Na＋ distribution were detected. The results showed that with the increment of salt concentration, the total leaf area, fresh weight and dry weight of two varieties decreased significantly, Quercus aliena var. pekingensis reduced by 30% , and Quercus aliena var. acuteserrata decreased by more than 50% , while the relative permeability of plasma membrane in leaves of two varieties increased, Quercus aliena var. acuteserrata increased by 29% , compared with Quercus aliena var. pekingensis. The SOD activity, proline and soluble protein contents of Q. acuteserrata were significantly lower than that of Q.pekingensis. More K＋ were transfered from root to stem and leaf, conversely more Na＋ stayed in root with two varieties. However, Q.pekingensis could maintain constant K ＋ content in 15 mg/g, as compared with Q.acuteserrata. Therefore, a conclusion could be drawn that both varieties were tolerant to less than 3‰ substrate salt. Salt tolerance of Q. pekingensis was better than that of Q. acuteserrata.