蒿柳雌株与雄株在高温胁迫下的生理差异及其变异

利用人工气候箱模拟高温环境,研究40 ℃/30 ℃(白天温度/晚上温度)处理下蒿柳雌株与雄株叶片电导率(EC)、超氧阴离子自由基(O·-2)产生速率、渗透调节物质含量以及抗氧化物酶活性的差异,分析各生理指标在雌株与雄株间的变异系数(VC)及分化系数(VST)。结果表明:高温胁迫下,蒿柳EC值、O·-2产生速率显著上升,但雌株EC值和O·-2产生速率显著大于雄株;脯氨酸(Pro)含量、可溶性蛋白(SP)含量显著升高,但雄株的渗透调节物质含量显著高于雌株;超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、抗坏血酸过氧化物酶(AsA-POD)活性显著上升,过氧化物酶(POD)活性显著下降,但雄株的4种酶活性显著高于雌株。高温处理下,蒿柳雌株与雄株各生理性状的变异系数(VC)较为接近,说明各生理性状在雌性个体与雄性个体间的变异较为一致。各生理性状的平均分化系数(VST)为17.06%,说明高温胁迫下各生理性状在雌、雄株间的变异小于雌、雄株内(无性系之间)的变异。综上所述,高温胁迫下蒿柳无性系在生理性状上存在丰富的变异,但雄株具有较强的调节、适应能力。因此,在育种工作中适当多选择雄株优树,有助于获得耐热性强的新种质。 

Physiological differences and variations in male and female plants of Salix viminalis under high temperature stress

In this study,we detected the physiological differences of male and female plants of Salix viminalis in electrical conductivity (EC) ,superoxide (O·-2) production rate,contents of osmotic adjustment substances and activities of antioxidant enzymes at 40 ℃/30 ℃(day temperature/night temperature) ,and analyzed the variable coefficient (VC) and differentiation coefficient (VST) of all physiological traits.The aim of this study was to provide reference for variety breeding and introduction.Under high temperature stress,EC value and O·-2 production rate increased significantly,but they were significantly higher in female plants than in male plants.Proline (Pro) and solute protein (SP) contents rose significantly,but the two contents in male plants were significantly higher than in female plants.The activities of superoxide dismutase (SOD) ,catalase (CAT) and ascorbate peroxidase (AsA-POD) went up significantly,the activity of peroxidase (POD) declined markedly,but the activities of the four enzymes in male plants were significantly higher than those in female plants.Similar VC values of all physiological traits in both sexes indicated that the variation of all physiological traits for male and female plants were consistent.The mean VST of all physiological traits (VST =17.06%) indicated that the variation between male and female plants was smaller than that within male and female plants (clones) .In general,abundant physiological variations under high temperature stress exist in clones of Salix viminalis,yet male plants possess more strongly regulated and adaptive ability.Thus,to obtain heat-resistance germplasm,male Salix viminalis plants should be selected in future breeding project.