干旱胁迫对甜叶菊生理指标及单株干叶产量的影响

为了给干旱胁迫条件下的甜叶菊栽培管理提供理论依据，利用温室盆栽法研究了干旱胁迫对不同种质材料甜叶菊生理指标及干叶产量的影响。结果表明：正常水分处理下5份甜叶菊种质材料的可溶性蛋白质含量、相对电导率、丙二醛（MDA）含量、超氧化物歧化酶（SOD）、过氧化物酶（POD）及甜叶菊单株干叶产量不同。随着干旱时间的持续，5份甜叶菊种质材料的可溶性蛋白质含量均表现为下降趋势，仅IS-1在T3（停止灌溉15天）略有上升；5份甜叶菊种质材料相对电导率均出现较平稳的显著增加；IS-1和AL-4叶片MDA的含量随着干旱胁迫时间的持续先降低后升高，而QF-1、‘青甜杂4’及JD-1叶片MDA的含量持续升高；SOD与POD的活性均表现出先升高后降低再升高的变化趋势；5份甜叶菊种质材料的单株干叶产量均出现不同程度的下降趋势。相同处理中不同材料的相同指标变化程度不同，说明其抗旱能力不同：其中IS-1最强，QF-1最弱，其他3份材料的抗旱性顺序分别为：AL-4>‘青甜杂4’>JD-1。

Effects of Drought Stress on the Physical index and Dry leaf yield of Stevia rebaudina Bertoni

The effects of drought stress on the physiological indices and the dry leaf yield in the different Stevia rebaudina Bertoni germplasms （IS-1, QF-1, Qingtianza4, JD-1 and AL-4） were investigated in a pot trial in greenhouse. It is found that significant differences in the content of soluble protein, the relative electric conductivity, the content of malondiadehyde （MDA）, the activities of peroxidase （POD） and superoxide dismutase （SOD） and the dry leaf yield were found among different germplasms. The content of soluble protein in five germplasms showed a decrease trend with drought stress time, but that in the IS-1 rose in the T3 without irrigation for 15 days. The relative electric conductivity showed stable and significant increase. The MAD content in the IS-1 and in the AL-4 decreased firstly and then increased, but that in the QF-1, Qingtianza4 and JD-1 increased continually. The dry leaf yield of five showed a decrease in varying degrees under drought stress, and different dermplasms had different varying degrees in the same treatment, indicating that the drought resistance of different germplasms was different. The strongest drought resistance was recorded in the IS-1, and the weakest in the QF-1. The order of the drought resistance in other germplasms was AL-4 Qingtianza4JD-1.