Cu胁迫对大花萱草生长及生理的影响

摘要

In order to investigate Hemerocallis middendorffii adaptive response in the heavy metal Cu stress , we studied its resist-ance to heavy metal , set up four different Cu contents ( 100, 400, 800, 1 200 mg・ kg-1 ) to treat H.middendorffii, and determined its growth , physiology and photosynthetic characteristics under Cu stress .In the same stress intensity with in-creasing stress time, there was different physiological variation .In the same time, when Cu content was 100 mg・ kg-1, it could promoted H.middendorfii growth, when Cu content was more than 400 mg・ kg-1 , it could inhibited H.middendorfii growth.With the increasing of Cu content , peroxidase ( POD) and superoxide dismutase ( SOD) activity increased signifi-cantly, but SOD activity increased and then decreased;H.middendorffii leaf chlorophyll content with increasing Cu content showed a decreasing trend after the first increase with the turning point of 100 mg・ kg-1 .Photosynthetic rate and transpira-tion rate appeared peak value at 10:00 am and 16:00 pm.H.middendorfii could adapt to less than 100 mg・ kg-1 for reme-diation in the Cu contaminated soil .%为了探讨大花萱草（ Hemerocallis middendorffii）在重金属Cu胁迫条件下的适应反应，揭示其抗重金属能力，设置了4个梯度Cu质量分数（100、400、800、1200 mg・ kg-1）处理大花萱草植株，并测定Cu胁迫下大花萱草生长、生理和光合特性。结果表明：在相同胁迫强度下，随着胁迫时间的增加，各生理指标出现了不同变化规律。同一时间内，Cu质量分数为100 mg・ kg-1时促进大花萱草的生长，大于400 mg・ kg-1时抑制其生长；随着Cu质量分数的增大，过氧化物酶（ POD）、超氧化物歧化酶（ SOD）的活性均明显增加，但SOD活性升高后又降低；大花萱草叶片叶绿素质量分数随Cu质量分数的增加呈先增加后降低趋势，转折点出现在100 mg・ kg-1处理水平上；光合速率（Pn）、蒸腾速率（Tr）均在10：00和16：00左右出现两个峰值。通过对大花萱草在不同重金属Cu胁迫条件下生长及生理特性的研究发现，大花萱草适应于质量分数小于100 mg・ kg-1的Cu污染土壤的修复。