三个苜蓿品种对镉污染的生理生态反应及抗性比较

Comparison of the resistance of three varieties of alfalfa to cadmium stress

研究了镉对苜蓿(3个品种)发芽势、发芽率、根长、芽长、根鲜重等形态指标和SOD活性等生理指标的影响,以及镉污染期细胞膜透性的变化情况。探讨了镉胁迫下3个苜蓿品种抗性的差异,结果表明:30mg.L-1 Cd处理,严重抑制胚根、胚芽的增长,且鲜重急剧下降,随Cd处理质量浓度加大,3个品种SOD活性都呈上升趋势,其中多叶苜蓿升幅最大。高Cd处理(50 mg.L-1),3个品种SOD活性均有所下降。重度胁迫下,3个品种相对电导率和地上部Cd含量都增大,且品种间差异显著,相对电导率以多叶苜蓿最小,准格尔苜蓿最大,Cd含量的顺序为准格尔苜蓿>肇东苜蓿>多叶苜蓿。综合评价多叶苜蓿抗性较强,肇东苜蓿次之,准格尔苜蓿抗性较弱。

The effects of cadmium on the seed germination rate, germination potential, embryo length, radicle length, the whole plant weight and the activities of SOD of three varieties of alfalfa are studied. The change of relative electrical conduction in the cadmium contamination are also studied. The paper probes the difference of resistance among three varieties of alfalfa （ Medicago sativa L. cv. Zhaodong, M. sativa L. cv. neimenggu Zhungeer, and 8925 M. sativa L. cv. duoye ） . The results show that, using 30 mg·L^-1 Cd deal with the alfalfa, it will seriously restrict growing of radicle and plumule and whole plant weight will decrease sharply. With the increase in Cd concentration, activities of SOD will appear a trend of increase in the three varieties of alfalfa. Among them, 8925 M. sativa L. cv. duoye is the most. Using 50 mg·L^-1 Cd to deal with the three varieties of alfalfa, activities of SOD will decrease together. Under the serious stress, the three plants＇ relative conductivity and the contents of Cd in the parts of above-ground will increase. Moreover, the differences among the three plants are obvious, and 8925 M. sativa L.cv. duoye is the minimum, and M. sativa L.cv. neimenggu Zhungeer is the maximum. The order of contents of Cd in the plants is M. sativa L. cv. neimenggu Zhungeer→Zhaodong→duoye. The resistance of 8925 M. sativa L. cv. duoye to Cd stress is higher than the other two varieties of alfalfa.