蚕豆幼苗期根系和叶片生理指标对UV-B辐射、铅镉胁迫和复合胁迫的响应

Response of physiological indexes of root system and leaves from broad beans seedling toward UV-B radiation,Pb+Cd stress and compound stress

对蚕豆种子及幼苗分别进行铅镉胁迫、UV-B辐射胁迫及UV-B辐射和铅镉复合胁迫处理,研究3种胁迫处理下蚕豆种子的萌发及蚕豆幼苗根系和叶片生理指标的变化情况.结果显示,与对照相比,3种胁迫处理下,蚕豆种子的发芽率、蚕豆幼苗根系生长速度、根系活力、蚕豆幼苗叶片内叶绿素含量、可溶性蛋白含量均呈降低趋势;蚕豆幼苗叶片内丙二醛和过氧化物酶含量呈升高趋势.各项指标对3种胁迫的敏感程度为:复合胁迫>UV-B辐射胁迫>铅镉胁迫.上述分析说明3种胁迫处理对蚕豆种子萌发、蚕豆幼苗生长及蚕豆幼苗根系和叶片生理指标均有不同程度地影响.

Broad bean seeds and seedlings were adopted to study the changes of seed germination and physiological inde- xes of root system and seedling leaves under Pb~ Cd stress, UV- B radiation stress and compound stress （UV- B＋Pb＋Cd）. The results were following： compared with the contrast, the germination rate of seed, the growth rate of seedling root, root vigor, chlorophyll content and soluble protein content of seedling leaves showed a decreased tendency; MDA content and peroxidase content of seedling leaves showed rising trend instead. The level of sensitivity of each index toward three kinds of stress was following： compound stress was greater than UV - B radiation stress and UV - B radiation stress was greater than Pb＋Cd stress. The above showed that seed germination and seedling growth and physiological indexes of root system and seedling leaves of broad beans were subject to the impact of varying degrees under three kinds of stress treatments.