不同生态型铺地黍光合特性对干旱胁迫的响应  

Response of Photosynthetic Characteristics of Different Ecotypes of Torpedograss to Drought Stress

作　　者：李志丹[1] 李婷婷 黄绮玉 黄晓燕 曾小龙[1] 高桂娟[1] 韩瑞宏[3] Li Zhidan;Li Tingting;Huang Qiyu;Huang Xiaoyan;Zeng Xiaoong;Gao Guijuan;Han Ruihong(Environmental Education Institute,Guangdong University of Education,Guangzhou 510000,China;Pingyuan Experimental Middle School,Meizhou 514000,China;Zhongkai University of Agriculture and Engineering,Guangzhou 510000,China)

机构地区：[1]广东第二师范学院环境教育研究所,广东广州510000 [2]广东省梅州市平远县实验中学,广东梅州514000 [3]仲恺农业工程学院,广东广州510000

出　　处：《中国野生植物资源》2023年第9期40-46,52,共8页Chinese Wild Plant Resources

基　　金：广东省普通高校重点领域专项项目(2021ZDZX4004);广东第二师范学院生态学科研团队项目(广东二师[2020]58号);广东省自然科学基金项目(2016ZC0204);大学生创新创业项目(202214278035)。

摘　　要：铺地黍(Panicum repens L.)因其较强的污染物净化力、抗旱耐淹能力,可广泛用于污染河岸消落带的生态修复。依托前期研究基础,选取广东(E‐guangdong)和海南(E‐hainan)两种生态型为材料,设置15%、30%和50%田间持水量三个处理,分别代表重度干旱、中度干旱和对照,通过盆栽实验,研究在不同水分条件下铺地黍形态特征和光合特性对干旱胁迫的响应规律。结果显示:干旱胁迫下铺地黍高度增加,与对照相比,高度增加34.7%~48%(E‐guangdong)和17.9%~19.8%(E‐hainan),与对照差异显著(P<0.05),而分枝数无显著变化。干旱胁迫对铺地黍光合系统有明显的影响,重度干旱胁迫下净光合速率、气孔导度、胞间CO_(2)浓度、蒸腾速率、实际光化学效率和最大光化学效率显著低于对照(P<0.05)。铺地黍水分利用效率随干旱程度增加而升高,重度干旱下显著高于对照和中度干旱(P<0.05),说明铺地黍通过降低蒸腾速率等参数提高水分利用效率来适应干旱胁迫。铺地黍通过调节叶绿素合成量来适应干旱胁迫,维持植物生长,叶绿素a、叶绿素b和叶绿素a+b含量呈现“V”型变化,在重度干旱胁迫下叶绿素含量显著高于中度胁迫(P<0.05)。两种生态型铺地黍均表现出较强的抗旱性,两者比较,E‐guangdong的形态特征、叶绿素含量、叶片光合气体交换参数值等整体表现优于E‐hainan,说明铺地黍的抗旱性可能与地理分布相关。Torpedograss can be widely used for ecological restoration of polluted river bank and water-level fluctuation for its strong pollutant purification ability,drought resistance and flood tolerance.Based on the previous research,two ecotypes of torpedograss which were collected from Guangdong(E-guang‐dong)and Hainan(E-hainan)respectively were used to study the morphological and physiological char‐acteristics under different drought stress(15%、30%、50%field capacity).The results showed that under water stress,the height of torpedograss increased by 34.7%to 48%(E-guangdong)and 17.9%to 19.8%(E-hainan)compared to the control,with significant differences(P<0.05),while there was no signifi‐cant change in the number of branches.Drought stress had a significant impact on the photosynthetic sys‐tem of torpedograss.Under severe drought stress,the net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2) concentration(Ci),transpiration rate(Tr),actual photochemical efficiency(ΦPSII),and maximum photochemical efficiency(Fv/Fm)of torpedograss were significantly lower than those of the control(P<0.05).The water use efficiency(WUE)of torpedograss increased with the in‐crease of drought severity and was significantly higher under severe drought stress than the control and moderate drought(P<0.05).It indicated that torpedograss adapted to drought stress by reducing transpi‐ration rate and other parameters to improve WUE.Torpedograss adapted to drought stress by regulating chlorophyll synthesis,maintaining plant growth.Chlorophyll a,chlorophyll b,and chlorophyll a+b showed a"V"shaped change,and the chlorophyll content was significantly higher under severe drought stress than under moderate stress(P<0.05).In general,the two ecotypes of torpedograss showed strong drought resistance.The overall performance of E-guangdong is better than E-hainan in morphological characteristics,chlorophyll content,leaf photosynthetic gas exchange parameter values,etc.Which indi‐cated that drought resistance of torpedogra

关 键 词：干旱胁迫 铺地黍生态型 形态特征 光合色素 荧光参数 

分 类 号：Q-9[生物学]