3个瑞典能源柳无性系对铅污染耐受性研究

摘要

To sudy utilization value of the energy willow on repairing Pb pollution environment,the sprout growth,root development and the physiological responses of willow clones cut seedlings on Pb poisoning,we selected 'Salix C','Salix E' and 'Salix 2' as the experiment materials by subordinate function to analysis the tolerance of test willow clones to Pb contamination.Under the conditions of 1/4 Hoagland liquid nutrient and different gradients of Pb concentration,the results showed that the slight Pb contamination (Pb 200 mg·L-1) promote growth for 'Salix C' and 'Salix 2'.The biomass of shoots and roots decreased as the increase of Pb concentration.With the Pb concentration rising (>Pb 400 mg·L-1),the cell membrane permeability increased.The content of chlorophyll decreases and then increases for 'Salix 2',others were continuously decreased and the content of chlorophyll mostly had significant difference to contrast.Subordinate function analysis showed that the tolerance of three willow clones to Pb concentration was in order of 'Salix C'＞'Salix 2'＞'Salix E'.Three willow clones all had some tolerance to Pb slight pollution with the standard of biomass decrease 20%.Thus,from the practice point of view on repairing Pb pollution,the energy willow is a better plant to repair Pb pollution.%以3个能源柳无性系[能源柳C(Salix fragilis)、能源柳E(Salix viminalis)、能源柳2(Salix dascladus)]插穗为材料,在水培条件下研究了3个无性系在不同浓度铅胁迫下的插穗萌条生长、根系发育和铅中毒的生理生态反应,并通过隶属函数法对它们耐铅性进行综合评价,探索瑞典能源柳在修复铅污染环境方面的利用价值.结果显示:低浓度铅胁迫(Pb 200 mg·L-1)能促进'能源柳C'和'能源柳2'根系的生长,同时根长增加、根数增多;当铅浓度继续增加时(>Pb 400 mg·L-1),3个能源柳无性系生物量显著下降(P<0.05).随着铅胁迫浓度的增加,3个无性系细胞膜透性显著高于对照(P<0.05);'能源柳2'叶片的叶绿素含量先上升后降低,其他2个无性系则持续降低,并大多与对照有显著差异.3个能源柳无性系的抗铅能力大小为'能源柳C'＞'能源柳2'＞'能源柳E'.研究发现,若以生物量减少20%作为指标来确定植物耐性临界值的上限标准,则3个能源柳无性系在铅污染环境中均有一定的适应性;能源柳是一种较好的耐铅性植物,可用于铅污染土壤的修复.