氯化胆碱和海藻糖对油菜蕾薹期干旱胁迫的缓解效应研究和耐旱指标筛选

为研究氯化胆碱和海藻糖对油菜蕾薹期干旱胁迫的缓解效应,本试验以5个油菜栽培品种为研究对象,在蕾薹期设置干旱胁迫、干旱胁迫下添加氯化胆碱及干旱胁迫下添加海藻糖3个处理,通过考察15个耐旱指标,探究不同处理对油菜蕾薹期形态、生长发育和生理特性的影响,并对3种处理下的油菜耐旱性进行综合评价和耐旱指标筛选。结果表明,干旱胁迫导致油菜株高、茎粗、总鲜重、地上部鲜重、超氧化物歧化酶(SOD)活性显著下降,可溶性蛋白、脯氨酸、丙二醛(MDA)含量极显著上升。添加氯化胆碱后,可溶性蛋白含量显著下降(34.96%);添加海藻糖处理后,SOD、过氧化物酶(POD)活性极显著升高(77.22%和183.93%),MDA和可溶性蛋白含量均极显著降低(64.68%和27.68%)。耐旱性效应综合评价表明,干旱胁迫下,淮油18号耐旱性最强(D=0.706),南农油3号耐旱性中等(D=0.476),秦优33、秦油10号和美国油王999耐旱性最差(D=0.364~0.404)。添加氯化胆碱(D值平均提高40.00%)较海藻糖(D值平均提高13.95%)起到更好的抵御干旱逆境的作用。本研究筛选出的根长、茎粗、总鲜重、根鲜重、地上部干重和总干重等指标,可作为油菜抗旱特性快速鉴定的指标(R²=0.992)。综上所述,外源氯化胆碱对干旱胁迫下蕾薹期油菜有更好的缓解作用,这为油菜的耐旱栽培提供了理论依据。

Drought Tolerance Effects of Choline Chloride and Trehalose on Rapeseed (Brassica napus L.) at Bud Stage Under Drought Stress and Selection of Related Indices

To investigate the alleviating effects of choline chloride and trehalose on drought stress at budding stage of rapeseed, three treatments including choline chloride and trehalose were added under drought stress for five rapeseed varieties. We investigated the effects of drought stress, as well as alleviated role of choline chloride (CC) or trehalose on the morphological, growth and physiological characteristics of rapeseed using fifteen drought tolerance indexes. Comprehensive drought tolerance performance and drought resistance indexes under the three treatments were further studied for the five varieties. The results showed that the plant height, stem diameter, total fresh weight, upper fresh weight and SOD activity of rapeseed decreased significantly under drought stress, and the contents of soluble protein, proline and MDA increased significantly. After adding choline chloride, the content of soluble protein decreased significantly (34.96%). Similarly, after adding trehalose, the activity of SOD and POD increased significantly (77.22% and 183.93%) and the content of MDA and soluble protein decreased significantly (64.68% and 27.68%). Three categories of drought tolerance for the five varieties were classified based on the comprehensive drought tolerance analysis: drought tolerance type (Huaiyou 18; D=0.706), intermediate type (Nannongyou 3; D=0.476), and non-drought tolerance type (including Qinyou 33, Qinyou 10, Meiguoyouwang 999; D=0.364~0.404); the alleviated effect of CC (The averaged D value increases 40.00%) was more effective than trehalose (The averaged D value increases 13.95%) in cultivars. In selection of drought tolerance index, root length, stem diameter, total fresh weight, root fresh weight, upper dry weight and total dry weight, could be served as the indicators to assess the drought tolerance of the rapeseed varieties (R²=0.992). This study suggested that the exogenous CC can alleviate the injuries under drought stress at bud stage, which provided a theoretical basis for improving drought resistant cultivation of rapeseed.