不同耐热型西瓜幼苗对高温胁迫的生理响应  

Physiological Response of Different Heat-tolerant Watermelon Seedlings to High Temperature Stress

作　　者：张梁葛 石文昕 李爱 张卫华 林萍 薛佳 ZHANG Liangge;SHI Wenxin;LI Ai;ZHANG Weihua;LIN Ping;XUE Jia(College of Horticulture and Landscape Architecture,Tianjin Agricultural University,Tianjin 300392,China)

机构地区：[1]天津农学院园艺园林学院,天津300392

出　　处：《华北农学报》2024年第5期117-127,共11页Acta Agriculturae Boreali-Sinica

基　　金：国家自然科学基金(61971312);国家级大学生创新创业训练计划(202310061077)。

摘　　要：为探究高温胁迫对不同耐热型西瓜自交系的影响,以热敏感型(D27)和耐热型(K53)西瓜幼苗为试验材料,在42℃高温胁迫下持续处理48 h,每12 h取样测定分析幼苗的表型、组织结构、光合特性、抗氧化酶活性和渗透调节物质等生理指标。结果显示,在高温胁迫后,耐热型K53的叶片厚度、栅栏组织厚度、海绵组织厚度和组织紧密度均比热敏感型D27大;D27栅海比的下降幅度大于K53。随着高温胁迫时间的增加,2个自交系的净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)均下降,胞间CO 2浓度(Ci)上升;且D27的变化幅度大于K53。在4个光合色素含量中,高温胁迫下,不同处理时间耐热型均高于热敏感型。2个自交系的超氧化物歧化酶活性(SOD)、过氧化物酶活性(POD)随着高温胁迫时间的增加均先升后降,24 h酶活性最大,且K53的酶活性均显著高于D27。高温胁迫后,2个自交系的相对电导率均升高,K53的相对电导率上升幅度小于D27;D27的丙二醛(MDA)含量降低;K53的MDA含量升高后降低。随着高温胁迫的时间增加,24 h时K53的可溶性蛋白含量和脯氨酸含量(Pro)均显著高于D27。综上所述,耐热型K53较热敏感型D27具有较强的抵抗高温胁迫能力。In order to explore the effects of high temperature stress on different heat-tolerant watermelon inbred lines,heat-sensitive(D27)and heat-tolerant(K53)watermelon seedlings were treated at 42℃for 48 h,and their phenotype,tissue structure,photosynthetic characteristics,antioxidant enzyme activities and osmotic regulators were measured and analyzed every 12 h.The results showed that the leaf thickness,fence tissue thickness,sponge tissue thickness and tissue compactness of heat-tolerant K53 were larger than those of heat-sensitive D27 after high temperature stress.The proportion of sponge tissue in the palisade tissue of D27 decreased more than that of K53.With the increase of high temperature stress time,the net photosynthetic rate(Pn),transpiration rate(Tr)and stomatal conductance(Gs)of the two inbred lines decreased,and the intercellular CO 2 concentration(Ci)increased.And the change amplitude of D27 was greater than that of K53.Among the four photosynthetic pigment contents,the heat-tolerant type was higher than the heat-sensitive type under high temperature stress at different treatment times.The superoxide dismutase(SOD)and peroxidase(POD)of the two inbred lines increased first and then decreased with the increase of high temperature stress time,and the enzyme activity was the highest at 24 h,and the enzyme activity of K53 was significantly higher than that of D27.After high temperature stress,the relative conductivity of the two inbred lines increased,and the relative conductivity of K53 increased less than that of D27.The malondialdehyde(MDA)content of D27 was reduced;the MDA content of K53 decreased after an increase.With the increase of high temperature stress,the soluble protein content and proline content(Pro)of K53 were significantly higher than those of D27 at 24 h.In summary,the heat-tolerant type K53 had a stronger resistance to high temperature stress than the heat-sensitive type D27.

关 键 词：西瓜 耐热性 高温胁迫 解剖结构 生理特性 

分 类 号：S651.01[农业科学—果树学]