作 者 ：王校锋,张文辉*,崔豫川
期 刊 ：西北植物学报 2013年 3期 页码：555~563
Keywords:energy willow, Hg2+ stress, root activity, antioxidant,
摘 要 ：以一年生瑞典能源柳4个无性系（N2、N4、NC、NE）幼苗为材料,通过盆栽试验,在对照、轻度、中度、重度Hg2+胁迫条件下,测定了4个能源柳无性系幼苗生长过程中生理生化指标,分析其对Hg2+胁迫的生理响应及其耐受性。结果表明:（1）随着土壤中Hg2+浓度的上升,4个能源柳无性系叶片保护酶POD、SOD和CAT活性均呈先上升后下降的趋势,且各无性系之间存在差异,其中NC的POD和CAT活性在重度胁迫下仍高于对照。（2）各无性系叶片中渗透性调节物质可溶性蛋白和脯氨酸(Pro)含量均呈先上升后下降的趋势,并均在轻度或中度胁迫下达到峰值,以可溶性蛋白含量变化幅度更大,在NC和NE无性系中表现得更明显。（3）随着土壤中Hg2+胁迫强度的加剧,N2、N4和NE无性系根系活力都呈现连续下降趋势,而NC无性系根系活力在轻度胁迫条件下则略微上升,然后持续下降,并均在中度和重度胁迫下达到显著水平,而且4个能源柳无性系叶片MDA含量均表现为先下降后上升趋势。（4）在轻度Hg2+胁迫下,N4和NE叶绿素含量和Chl a/Chl b值呈下降趋势,而N2和NC则稍微上升；在中度和重度胁迫下,4个能源柳无性系叶绿素含量和Chl a/Chl b值迅速下降,但能源柳各无性系的下降速度存在差异,其中N4下降幅度最大,NC最小。（5）运用隶属函数模糊评判法综合评价表明,各能源柳无性系对Hg2+的耐受性表现为:NC>NE>N4>N2。研究认为,在不同程度Hg2+胁迫条件下,4个瑞典能源柳无性系通过提高自身保护酶活性、抗氧化物质GSH含量以及有机渗透物质含量来有效缓解胁迫伤害,从而对Hg2+表现出一定的耐性,并以无性系NC的耐受性较好。
Abstract:We studied the mercury stress of through potted 1-year old seedlings four different energy willow clones (N2,N4,NC,NE),and conducted Hg2+ stress experiment,measured the physiological and biochemical indices,then all the parameters were used to evaluate the potential Hg2+ tolerance through the subordinate function method and screening out the tolerance heavy metal Hg2+ potential energy willow clones.The results show that:(1)With the rise of the soil Hg2+ concentration,the four energy willow clones protective enzymes POD,SOD and CAT activities showed a trend of increased and then decreased,the resistance of the 4 energy willow clones is different,but NC’s POD and CAT activities still higher than CK under severe stress;(2)The content of soluble protein and proline in the leaves of all clones are showing a trend of increased and then decreased with the heavy metals Hg2+ stress intensifies,all the energy willow clones reached the peak in the mild or moderate stress,and the rate of decline of soluble protein content is larger,this phenomenon showed more obvious in NC and NE clones;(3)With the heavy metals Hg2+ stress intensifies,the root activities of N2,N4 and NE showed a trend of decreased,but NC’s rise slightly under mild stress,then showed a trend of decreased;and the content of MDA of four energy willow clones showed a trend of decreased,and reached the significant level under moderate and severe stress;(4)Under mild Hg2+ stress,N4 and NE’s chlorophyll content and Chl a/Chl b value are presented descending trend,while N2 and NC’s is slight rise ;under moderate and severe stress,four energy willow clones chlorophyll content and Chl a/Chl b value are fallen rapidly,but the rate of decline of four energy clones are differences,the rate of decline of N4 is maximum,NC’s is minimum;(5)Using membership function of fuzzy evaluation method for comprehensive evaluation of four energy willow clones of Hg2+ tolerated,the result indicated that:Salix C>Salix E>Salix 4>Salix 2.Thereby under different intension of Hg2+ stress,four energy willow clones can adjust its protective enzymes activities,GSH content and organic osmolytes content to relieve the stress of Hg2+,showing some tolerance to heavy metal stress of Hg2+,and the tolerance potential of NC is the best.