不同品种杞柳对高锌胁迫的忍耐与积累研究

采用营养液培养实验方法,研究了高浓度Zn对3个杞柳品种"微山湖","大红头"、"一枝笔"生长,耐性及Zn吸收积累的影响.结果表明,Zn对杞柳生长的影响与品种、植物部位以及介质中Zn浓度有关,低Zn(100 μmol·L-1)、高Zn(1 000 μmol·L-1)均不同程度降低了3个杞柳品种的生长参数,低Zn显著减少了"微山湖"、"大红头"的根长及"大红头"根生物量,高Zn显著降低了3个品种株高、根长、生物量等生长参数;3个品种对Zn吸收与积累存在一定差异,地上部Zn含量随介质中Zn浓度升高而降低,根系中Zn含量随Zn浓度升高而增加,Zn在根中含量高于地上部,低Zn时3个品种地上部Zn含量为1477.58～1 583.19 μg·g-1,平均1 530.29 μg·g-1;位移系数(TF)随Zn浓度升高而降低,低Zn时"微山湖"、"一枝笔"位移系数高于"大红头"而接近1;迁移总量随Zn处理浓度增加而降低,3个品种迁移总量为2 332.58～3 871.41 μg,平均3 266.27μg,迁移总量比大于1;耐性指数(TI)随营养液中Zn浓度增加而降低,低Zn时3个品种耐性指数均大于0.5.以上结果表明,高Zn严重干扰了3个杞柳品种的生长,3个品种对低Zn有较强的耐性及积累能力,显示出具有修复≤100 μmol·L-1Zn潜力.

Tolerance of different varieties of Salix integra to high zinc stress

The effect of high Zn stress on Zn uptake, accumulation and the growth of three varieties of Salix integra were analyzed through nutrient solution culture. The results show that the influence of Zn treatment on growth parameters is related to plant variety, plant part and Zn concentration. Growth parameters of the three varieties are retarded at Zn concentration of 100 μmol · L~(-1)(low) and 1 000 μmol · L~(-1)(high). Root length of 'Weishanhu' and 'Dahongtou', and root biomass of 'Dahongtou' significantly drop in low Zn concentration. Stem height, root length and biomass markedly reduce in high Zn concentration. Zn uptake and accumulation vary with plant variety and shoot Zn content decreases with increasing Zn concentration. However, root Zn content increases with elevated Zn concentration. Root Zn concentration is generally higher than that of shoot. For the different plant varieties, shoot Zn concentration ranges from 1 477.58 to 1 583.19 μg · g~(-1) in low concentration Zn with an average of 1 530.29 μg · g~(-1). Translocation factor (TF) decreases with Zn concentration increasing with TF for 'Weishanhu' and 'Yizhibi' higher than that for 'Dahongtou'. Shoot total Zn content decreases with increasing Zn concentration. Shoot total Zn amount from 2 332.58 to 3 871.41 u.g with an average of 3 266.27 μg. Shoot/root total Zn ratio is in excess of 1 for three varieties. Tolerance index (TT) decreases with increasing Zn concentration, which is above 0.5 for the three varieties in low Zn concentration. This study suggests that high Zn concentration severely inhibits growth of S. integra. The three varieties have strong tolerance and high accumulation capacity in low Zn concentration. This shows that S. integra has a high potential for phytoextraction of Zn, whose concentration is not higher than 100 μmol · L~(-1).