【摘要】 通过盆栽形式,采用自然降雨加人工补水的控水方法,分析了四个马铃薯（Solanum tuberosum）品种在对照（土壤体积含水量为65%～75%）与两种不同干旱水平处理（中度干旱:土壤体积含水量30%～70%;重度干旱:土壤体积含水量7%～70%）条件下的耐旱系数（DTC）、相对叶绿素含量（SPAD值）、光合特性及生理生化指标的变化。结果表明:在中度干旱（T1）处理下,各品种耐旱性评价次序为‘冀张薯12号’>‘陇薯3号’>‘费乌瑞它’>‘陇薯6号’;在重度干旱（T2）处理下为‘费乌瑞它’>‘冀张薯12号’>‘陇薯3号’>‘陇薯6号’,说明马铃薯耐旱性的评价应结合干旱胁迫的具体条件。与对照相比, T1和T2处理下马铃薯SPAD值升高,但叶片净光合速率（P_n）、气孔导度（G_s）和块茎产量下降,说明这种相对叶绿素含量的增加可能与光合作用的碳同化无关,属于"非功能性"的持绿。T1处理下,不同品种的相对叶绿素含量变化量的最大值(ΔSPAD_max)与其DTC显著负相关,与超氧化物歧化酶活性的变化量（ΔSOD）显著正相关,说明"非功能性"持绿与干旱胁迫下氧化应激反应及品种耐旱性有关。而T2处理下, DTC与?SPAD_max和氧化防御性酶活无显著相关性,说明SPAD值和抗氧化酶活性能否作为耐旱性的评价指标依赖于所处的干旱水平。这一研究的发现将对不同干旱水平下马铃薯光合特性和耐旱性相关问题的深入研究提供基础。更多还原

【Abstract】 A semi-quantitative hydration control method using artificial hydration plus natural rainfall is adopted during the pot experiment of potato（Solanum tuberosum）. The drought tolerance coefficient, leaf greenness, photosynthetic characteristics, and physiological and biochemical indices of four potato cultivars under different treatment scenarios（30%–70% of soil volumetric water content as moderate drought, and 7%–70% as heavy drought） and control（65%–75% of soil volumetric water content） were analyzed. The results show that under the moderate drought（T1） treatment, according to the drought tolerance coefficient, the drought tolerance of each cultivar was ranked as following: ’Jizhangshu No.12’ > ’Longshu No.3’ > ’Favorita’ > ’Longshu No.6’; under severe drought（T2） treatment, it was: ’Favorita’ > ’Jizhangshu No.12’ > ’Longshu No.3’ > ’Longshu No.6’. These results suggest that the evaluation of drought tolerance of potato should be combined with the specific conditions of drought stresses. Compared to the control, under the treatments of T1 and T2, the leaf greenness（SPAD value） of the potato increased, but the net photosynthetic rate, stomatal conductance and tuber yield decreased, indicating that the increase of the leaf greenness may be independent of the carbon assimilation of photosynthesis, which is called "non-functional" stay-green. Under T1 treatment, ΔSPAD_max of different varieties was significantly negatively correlated with drought tolerance coefficient, and positively correlated with ΔSOD activity, indicating that oxidative stress response and drought tolerance were related to "non-functional" stay-green. However, under T2 treatment, drought tolerance coefficient had no significant correlation with ΔSPAD_max and oxidative defense enzyme activities, indicating whether SPAD and oxidative stress response can be used as indicators of drought tolerance evaluation depends on the level of drought. This study may motivate future research into issues related to photosynthetic characteristics and drought tolerance of potato under different drought scenarios.更多还原