不同抗旱性花生品种结荚期叶片生理特性

Leaf physiological traits at pod-setting stage in peanut cultivars with different drought resistance

以12个花生品种为试验材料,在人工控水条件下,于结荚期设置0~80 cm土层相对含水量为70%和50%2个处理,研究与花生抗旱性相关的叶片生理生化性状及不同品种抗旱的叶片机制.结果表明：利用产量抗旱系数可将12个花生品种的抗旱性分为强、中、弱3级,抗旱性强的品种有A596、山花11号、如皋西洋生,中度抗旱品种有花育20、农大818、海花1号、山花9号和79266,抗旱性弱的品种有ICG6848、白沙1016、花17和蓬莱一窝猴.A596、山花11号、如皋西洋生的抗旱机制是具有较强的叶片抗氧化保护能力、较高的PSⅡ活性及光合速率（Pn）.海花1号的叶片抗氧化保护能力较强,山花9号的PSⅡ活性有显著优势.相关分析表明,叶片Pn、气孔限制值（Ls）、最大光化学效率（Fv/Fm）、光化学猝灭系数（qP）、丙二醛（MDA）含量、相对电导率和超氧化物歧化酶（SOD）活性与花生品种的抗旱系数有显著的相关性,是花生结荚期的重要抗旱性状.SOD活性的抗旱级别需在干旱胁迫下鉴定,其他性状可在正常灌水条件下鉴定.山花11号和79266可分别作为花生强、弱抗旱性鉴定的标准品种,山花11号可作为花生叶片优异抗旱性状鉴定的标准品种.

With twelve peanut cultivars grown under artificial water control, the drought resistance related physiological and biochemical traits and the drought resistance mechanism of peanut leaves were studied. Two water treatments were designed, that were 50% and 70% of the soil relative wa- ter content of the 0-80 cm soil layer, respectively, at pod-setting stage. The results showed that the twelve peanut cultivars could be grouped into three different resistance levels based on their yield drought resistance coefficient. The A596, Shanhua 11 and Rugaoxiyangsheng were grouped as culti- vars with high resistance, while Huayu 20, Nongda 818, Haihua 1, Shanhua 9 and 79266 with moderate resistance, and the ICG6848, Baisha 1016, Hua 17 and Penglaiyiwohou with weak resist- ance. The mechanism of high drought resistance in peanut eultivars of A596, Shanhua 11 and Rug- aoxiyangsheng were due to more powerful antioxidant capacity, higher activity of photosystem 11 （ PS ]1 ） and photosynthetic rate （ Pn ）. By contrast, the moderate resistant cultivars Haihua 1 had stronger antioxidant protection capability, and the Shanhua 9 had much higher PS II activity. The Pn, stomatal limitation value （Ls ）, maximal photochemical efficiency of PS 1I （ Fv/Fm ） , photo- chemical quenching coefficient （ qp ）, content of malondialdehyde （ MDA）, relative electric con- ductivity and superoxide dismutase （SOD） activity of leaves were very significantly correlated with the drought resistance coefficient. Therefore, they were important indicative traits for the drought resistance at pod-setting stage of peanuts. These traits could be evaluated under normal irrigation condition except that the SOD activity should be identified under drought stress. Based on this study, we proposed that Shanhua 11 and 79266 could serve as standard cuhivars of high drought resistance and weak drought resistance, respectively. Shanhua 11 could also serve as a standard cultivar for identification of leaf drought resistance traits in peanut.