PEG渗透胁迫下藏沙蒿种质资源萌发特性及抗旱性评价

Evaluation of germination characteristics and drought resistance of Artemisia wellbyi germplasm under PEG osmotic stress

摘要:

【目的】评价藏沙蒿野生种质材料萌发期抗旱性。【方法】以采自西藏地区不同生境的 13 份藏沙蒿（Artemisia wellbyi）种质材料为研究对象 ，设置聚乙二醇（PEG ‐ 6000）浓度梯度分别为 0、 -0. 20、-0. 40、-0. 60 和-0. 86 MPa 共 5 个渗透胁迫处理，研究 PEG‐6000 渗透胁迫对藏沙蒿材料萌发特性的影响，并采用主成分分析和隶属函数两种方法对其抗旱性进行综合评价。【结果】 PEG 渗透胁迫降低了藏沙蒿种子的相对发芽势、相对发芽率、相对活力指数和萌发胁迫指数。藏沙蒿在受到干旱胁迫时通过推迟发芽时间、抑制芽长和促进根长来应对干旱胁迫。通过主成分分析，筛选出相对发芽势、相对发芽率、相对根长、相对活力指数和萌发胁迫指数 5 个抗旱性指标。【结论】主成分分析和隶属函数法综合评价认为，抗旱性较强的种质材料为 5、11 和 4 号，抗旱性较弱的为 13 号材料。

Abstract:

【Objective】 The aim of this research was toto evaluate the drought resistance of Artemisia wellbyi wild germplasm materials at the germination stage.【Method】 We selected thirteen A. wellbyi germplasm materials collected from various habitats in Tibet as the research subjects and applied five osmotic stress treatments using a PEG‐6000 concentration gradient of 0，-0. 2，-0. 4，-0. 6 and -0. 86 MPa. Our aim was to investigate the effects of PEG ‐ 6000 osmotic stress on the germination characteristics of A. artemisia，and comprehensively evaluate its drought resistance using Principal Component Analysis and Membership Function method.【Result】 PEG osmotic stress reduced the relative germination potential，relative germination percentage，relative vigor index and germination stress index of A. wellbyi seeds. A. wellbyi responded to drought stress by delaying germination time，inhibiting bud length and promoting root length. Through principal component analysis，we identified five drought resistance indexes： relative germination potential，relative germination rate，relative root length，relative vigor index and germination stress index.【Conclusion】 Based on the comprehensive evaluation using two methods，materials No. 5、11 and 4 ranked as the top three in drought resistance，while material No. 13 ranked the lowest in drought resistance.