4个甘蔗主栽品种对干旱胁迫的生理响应

为探究短期干旱胁迫下甘蔗伸长期的生理响应,本研究以4个栽培推广面积较大的甘蔗品种‘云蔗08-1609’‘粤糖93-159’‘新台糖22号’和‘桂糖42号’为供试材料,采用人工盆栽控水法,设置正常浇水对照（土壤含水量占田间持水量的80%以上）和轻度干旱（50%~60%）、中度干旱（40%~50%）和重度干旱（30%~40%）3个干旱处理,研究不同甘蔗品种在干旱胁迫下抗氧化酶系统、抗坏血酸-谷胱甘肽（AsA-GSH）循环系统、植株受损状况以及脱落酸（ABA）含量的变化规律。结果表明：干旱胁迫导致4个甘蔗品种的SOD、POD、CAT和GR活性显著提高（P<0.05,下同）;AsA、GSH含量随着干旱时间显著上升;除‘云蔗08-1609’的GSSG表现出先升后降的趋势外,其他3个品种的GSSG含量不断上升;‘云蔗08-1609’的GSH/GSSG值不断上升,‘新台糖22号’不断下降,‘粤糖93-159’和‘桂糖42号’表现出先升后降;干旱胁迫造成4个品种的MDA和质膜透性显著增加,叶片相对含水率显著降低;除‘桂糖42号’的ABA含量表现为先上升后下降的趋势外,其他3个品种干旱胁迫下ABA含量表现为升-降-升的趋势。综上表明：干旱胁迫造成4个甘蔗品种的SOD、POD、CAT活性及GR、ABA、AsA、GSH、GSSG含量显著上升。MDA和质膜透性提高,绿叶率和叶片相对含水率下降。本研究发现不同品种甘蔗干旱胁迫下的响应规律各不相同,‘云蔗08-1609’在干旱胁迫下ABA和叶片相对含水率含量最高,SOD、CAT、POD和GR活性在干旱初期响应最快,质膜透性最小。‘新台糖22号’和‘桂糖42号’在AsA-GSH循环中具有较高的AsA、GSH、GSSG含量。‘粤糖93-159’具有较高的POD和CAT活性以及较低的MDA含量。

Physiological Responses of Four Major Sugarcane Cultivars to Drought Stress

In order to explore the changing trend of sugarcane physiological response during elongation under drought stress, four main sugarcane cultivars in China, ‘Yunzhe 08-1609’, ‘Yuetang 93-159’, ‘ROC22’ and ‘Guitang 42’, were used as the test materials. By adopting the method of artificial potted water control (soil water content accounted for more than 80% of field capacity), and 3 different gradients of drought stress treatment of mild drought (50%-60%), moderate drought (40%-50%) and severe drought (30%-40%) were set. In this experiment, the antioxidant enzyme system, ascorbic acid-glutathione (AsA-GSH) circulation system, plant damage status and abscisic acid (ABA) content in different sugarcane cultivars under drought stress were measured and studied. The test results showed that the activity of SOD, POD, CAT and GR in the 4 sugarcane cultivars significantly increased by drought stress (P<0.05, the same below); the content of AsA and GSH increased significantly with the drought time. The GSSG content in the other 3 cultivars except for ‘Yunzhe 08-1609’ continued to rise, showing a trend of first rising and then falling; the GSH/GSSG value in ‘Yunzhe 08-1609’ continued to rise, that in ‘ROC22’ continued to decline, that in ‘Yuetang 93-159’ and ‘Guitang 42’ showed a continuous increase. The MDA and plasma membrane permeability in the 4 cultivars increased significantly, and the relative water content in leaves decreased significantly; except for ‘Guitang 42’ which ABA content showed a trend of first increase and then decrease, the other 3 cultivars showed a trend of increasing first and then decreasing. Under drought stress, the ABA content showed a trend of rising-falling-rising. To sum up, drought stress caused a significant increase in SOD, POD, CAT, GR activity and ABA, AsA, GSH and GSSG contents in the 4 sugarcane cultivars. The permeability of MDA and plasma membrane increased, and the relative water content of leaves decreased. ‘Yunzhe 08-1609’ had the highest ABA and relative water content in leaves under drought stress, while SOD, CAT, POD and GR activity responding the fastest at the early stage of drought, and the plasma membrane permeability was the lowest. ‘ROC 22’ and ‘Guitang 42’ had higher AsA, GSH and GSSG contents in the AsA-GSH cycle. ‘Yuetang 93-159’ had higher POD and CAT activity and lower MDA content. The growth characteristics of sugarcane cultivars were different in different climate conditions and growth stages. ‘Yunzhe 08-1609’ was suitable for planting in Yunnan climatic conditions. In this experiment, the drought resistance performance in Yunnan was better; ‘Guitang 42’ was widely planted in Guangxi, suitable for the climatic conditions of Guangxi. ‘Yuetang 93-159’ was a high-sugar variety but has poor drought resistance. ‘ROC22’ has been cultivated for many years and faces the problem of characteristic degradation. Therefore, this study discussed the response characteristics of the 4 cultivars under drought stress, and the drought resistance should be analyzed in combination with field experiments.