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研究了水培条件下不同铜水平(CK、5、10、15、20、25μmol.L-1)对豆科植物紫云英(Astragalus sinicus)根、茎、叶生长发育的影响。结果表明:5μmol.L-1铜对紫云英根、茎、叶和根瘤生长均有促进作用,地下部(根)、地上部(茎叶)生物量显著增加,株高增加,根瘤呈粉色、多为复瘤、聚生,单瘤比对照大;当铜水平达10μmol.L-1时,地下部根的生物量增加依然达到显著水平(P<0.05),株高较对照增加,但地上部生物量与对照无显著差异,根伸长受抑制,根长显著缩短;当铜水平达15μmol.L-1时,紫云英植株开始表现受害症状,根色转褐,叶片转黄,根瘤着生数量、根和地上部干质量以及分枝数均显著减少(P<0.05)。当铜水平提高到20mmol.L-1以上时,紫云英株高显著变矮,根长、根鲜质量和干质量、分枝数、株高/根长、地上部鲜质量和干质量也均随着铜水平提高而显著减少或降低。通过光镜和投射电镜观察,发现紫云英污染叶变厚,其原因是叶片细胞膨大和栅栏组织增厚;叶片转黄与叶绿体遭破坏有关;根系部分皮层细胞死亡可能影响根系吸水和植株水分运输,导致植株含水率降低。
The effects of different copper levels (CK, 5, 10, 15, 20 and 25μmol.L-1) on the growth, development and development of legumes Astragalus sinicus were studied under hydroponics. The results showed that: 5μmol.L-1 copper promoted the growth of roots, stems, leaves and nodules of Astragalus sinicus. The biomass of underground (roots) and shoots (stems and leaves) increased significantly, the plant height increased, (P <0.05). However, when the copper level reached 10μmol.L-1, the biomass of underground roots was still significantly increased (P <0.05), but the plant height was higher than that of the control The biomass of shoots had no significant difference with that of the control, the root elongation was inhibited and the root length was significantly shortened. When the copper level reached 15μmol.L-1, The number of root nodules, root and shoot dry weight and number of branches were significantly decreased (P <0.05). When the copper level increased to above 20mmol.L-1, the plant height was significantly shorter, root length, root fresh weight and dry weight, number of branches, plant height / root length, shoot fresh weight and dry weight All decreased or decreased significantly with the increase of copper level. The result of light microscope and transmission electron microscope showed that the polluted leaves became thick due to the enlargement of the leaf cells and the thickening of the palisade tissue. The yellowing of the leaves was related to the destruction of the chloroplasts. The death of some cortical cells in the root system may affect the water absorption and the water content of the plants Transport, resulting in reduced plant moisture content.