湿害胁迫下不同种源地桔梗生理响应及耐湿性评价

摘要

以不同种源地6份桔梗种质为供试材料,采用人工控水方式在土壤饱和持水量状态下对桔梗进行持续湿害处理,研究湿害胁迫对株高、分枝数目、地下鲜质量和地下干质量等生长生理指标的影响,比较不同种源地材料对湿害胁迫的生理响应差异,并以主成分分析为基础结合隶属函数法与聚类分析法对6份种质材料的19个生长生理指标进行综合评定.结果表明:湿害处理下,6份桔梗种质耐受性存在明显差异.湿害胁迫促进了多数材料的株高、分枝数目、主茎粗度和地上鲜质量的增长,同时抑制了地下鲜质量和地下干质量的变化,普遍降低了根冠比.湿害处理后,桔梗叶绿素含量、净光合速率和气孔导度等指标均不同程度降低,脯氨酸含量也下降,而丙二醛、细胞膜透性等指标则因种质不同呈现出不同结果.分析表明,材料St为高耐湿性种质,材料Sa为中等耐湿性种质,而其余种源地材料为耐湿性较弱种质.%With the continuous waterlogging stress treatment to Platycodon grandiflorum from six prove-nances,the influence of waterlogging stress on plant height,branch number,fresh mass and dry mass of under-ground part was studied,and the physiological responses of different germplasm materials to waterlogging stress were compared.Through principal component analysis and subordinate function analysis,a comprehensive eval-uation was conducted on the waterlogging-resistance of 19 growth and physiological indexes of six germplasm materials.It was found that different germplasm materials exhibited great difference in waterlogging tolerance based on the degree of injury severity.Waterlogging stress increased plant height,branch number,diameter of main stem,fresh mass in aerial part of plants for most materials,while restraining the fresh mass and dry mass of the underground part of plants and reducing the root/shoot ratio.After waterlogging stress,all waterlogging-treated materials exhibited a decline in stomatal conductance,net photosynthetic,chlorophyll and Pro content, but for membrane permeability,MDA and other indexes,it had both positive and negative effects depending on the tested germplasm material. These results showed that the material St was waterlogging tolerant, while the material Sa was among the medium,and the rest materials were waterlogging sensitive.