镉胁迫下柳枝稷的生理响应及耐镉性

Physioligcal Response and Tolerance of Switchgrass to Cd Stress

为探明柳枝稷(Panicum virgatum L.)在镉(Cd)胁迫下的生理变化与耐性,选取柳枝稷低地型品种Alamo以改良Hoagland营养液培养,用CdCl_2 0μmol/L(CK)、5μmol/L、10μmol/L、20μmol/L和30μmol/L胁迫2周后收苗,测定柳枝稷株高、根长、含水量、生物量和叶绿素含量,并进行相关性分析。结果表明:随Cd浓度增加柳枝稷植株的增高、根系伸长及根含水量呈下降趋势;与CK相比,当Cd浓度在10μmol/L及其以上时,根系伸长和根含水量显著(P<0.05)下降;Cd浓度在20μmol/L及其以上时,植株增高显著降低;生物量、茎叶含水量与叶绿素a、叶绿素b和总叶绿素含量各处理间差异不显著(P>0.05);Cd浓度与柳枝稷植株的增高、根系伸长、根含水量、茎叶含水量呈显著或极显著负相关,与生物量呈正相关但不显著。Alamo对Cd胁迫具有一定的耐性。

In order to study the physiological variation and tolerance of switchgrass under Cd stress, a culture experiment was conducted with the low-lying switchgrass cultivar Alamo and Hoagland nutrient solution, different concentrations of CdCl2 （0 μmol/L, 5 μmol/L, 10 μmol/L, 20 μmol/L, 30 μmol/L） were added to explore the effects of Cd stress on plant height, root length, moisture content, biomass and chlorophyll content, then the correlations were analyzed as well. Results： The plant height increasing, root extending and moisture content decreased with Cd concentration increasing; Root extending and moisture content significantly decreased when Cd concentration exceeding 10 μmol/L; compared with CK, Plant height increasing significantly decreased when Cd concentration was above 10 μmol/L; Biomass and moisture content in stem and leaf had no significant correlation with contents of chlorophyll a, chlorophyll b and total chlorophyll; Cd concentration significantly or even highly significantly negatively correlated with plant height increasing, root extending, root moisture content, moisture content in stem and leaf, and non-significantly positively correlated with biomass. Alamo has a certain degree of tolerance to Cd stress.