低温胁迫对番茄幼苗不同叶龄叶片叶绿素荧光成像特性的影响  

Effects of Chilling on Chlorophyll Fluorescence Imaging Characteristics of Leaves with Different Leaf Ages in Tomato Seedlings

作　　者：胡雪华[1] 刘宁宁 陶慧敏 彭可佳 夏晓剑[2] 胡文海[1] HU XueHua;LIU NingNing;TAO HuiMin;PENG KeJia;XIA Xiaojian;HU WenHai(School of Life Sciences,Jinggangshan University,Ji’an 343009,Jiangxi;College of Agriculture and Biotechnology,Zhejiang University,Hangzhou 310058)

机构地区：[1]井冈山大学生命科学学院,江西吉安333009 [2]浙江大学农业与生物技术学院园艺系,杭州310058

出　　处：《中国农业科学》2022年第24期4969-4980,共12页Scientia Agricultura Sinica

基　　金：江西省自然科学基金重点项目(2019ACB20017)。

摘　　要：【目的】研究番茄幼苗第2叶(成熟叶)和第4叶(新生叶)叶绿素荧光成像特性对低温胁迫的响应,并分析低温胁迫下番茄不同叶龄叶片光合活性区域相对面积及荧光参数值的变化,以探明番茄幼苗不同叶龄叶片对低温胁迫的适应机制。【方法】以番茄品种‘中蔬4号’(Solanum lycopersicum L.cv Zhongshu No.4)4叶期幼苗为材料,对番茄幼苗进行低温(8℃、200μmol·m^(-2)·s^(-1))处理15 d后常温(26℃白天/20℃夜晚,500μmol·m^(-2)·s^(-1))恢复1 d,于处理不同时期对幼苗全株进行叶绿素荧光成像,并比较第2叶和第4叶的叶绿素荧光成像特性。【结果】低温处理期间,第4叶的光合活性区域相对面积(R_(AP))仅在处理前期(5 d)有所下降,而全株和第2叶的R_(AP)则随处理时间的延长持续下降,但常温1 d即可完全恢复。低温处理下PSII调节性能量耗散的量子产量(Y(NPQ))、PSⅡ非调节性能量耗散的量子产量(Y(NO))和非光化学猝灭(NPQ)的荧光活性区域相对面积(R_(AF))与R_(AP)基本一致,但PSII实际光化学效率(Y(Ⅱ))和光化学猝灭(qP)的R_(AF)则显著低于R_(AP)。低温处理前期(5 d),番茄幼苗光合活性区域的PSII最大光化学效率(Fv/Fm)、Y(NPQ)、NPQ急剧下降和Y(NO)急剧上升,随后,Fv/Fm保持不变,但Y(NPQ)和NPQ有所上升,Y(NO)则下降。但是,低温处理1 d即导致光合活性区域Y(Ⅱ)的急剧下降,随后维持不变。另外,番茄全株和第4叶的光合活性区域qP仅表现在处理第1天时小幅下降,随后则维持高于处理前的水平,而第2叶qP则在第5天有明显上升后又迅速下降。总体上,第4叶光合活性区域的Fv/Fm、Y(Ⅱ)、Y(NPQ)、NPQ和qP明显高于第2叶,Y(NO)低于第2叶。【结论】番茄幼苗可通过主动降低叶片光合活性区域面积来适应低温胁迫,而叶片热耗散能力在低温处理前期受到抑制,直到处理后期才逐渐发挥其光保护作用;低温胁迫下番茄幼苗优先保护生长点和新【Objective】This study analyzed the characteristics of chlorophyll fluorescence imaging of the 2nd (mature) and 4th (newly born) leaves of tomato seedlings in response to chilling stress,aiming to probe the mechanism of leaves with different ages adapted to chilling stress in tomato seedlings.【Method】In this study,Solanum lycopersicum L.cv Zhongshu No.4 was used as the research material.The tomato seedlings in the 4-leaf stage were treated at chilling (8℃,200μmol·m^(-2)·s^(-1)) for 15 d and then recovered at normal temperature (26℃day/20℃night,500μmol·m^(-2)·s^(-1)) for 1 d.The Chlorophyll fluorescence imagings of the whole seedlings were measured at different stages under different treatments,and the characteristics of chlorophyll fluorescence imaging of the 2nd and 4th leaves were compared.【Result】The results showed that the relative area of photosynthetically active regions (R_(AP)) on the4th leaves decreased slowly during the first 5 d of the chilling stress,while the R_(AP)on the 2nd leaves and the whole plants decreased steadily during the whole chilling treatment.The R_(AP)recovered completely after 1 d of recovery.Under chilling treatment,the relative area of fluorescence active regions (R_(AF)) for quantum yield of regulatory energy dissipation (Y(NPQ)),quantum yield of nonregulatory energy dissipation (Y(NO)),and nonphotochemical quenching (NPQ) showed similar changes as that of R_(AP).However,the R_(AF)of effective PSⅡ quantum yield (Y(Ⅱ)) and coefficient of photochemical quenching (qP) were significantly lower than that of R_(AP).The maximum PSⅡ quantum yield (Fv/Fm),Y(NPQ),and NPQ decreased while Y(NO) increased sharply in the photosynthetically active region in tomato seedlings during the first 5 d of the chilling treatment.In the following days,the Fv/Fm remained unchanged,whereas Y(NPQ) and NPQ increased and Y(NO) decreased.However,Y(Ⅱ) declined sharply 1 d after chilling stress and then remained unchanged.Interestingly,qP in the photosynthetic active region of the 4

关 键 词：番茄 低温胁迫 叶绿素荧光成像 光抑制 叶龄 

分 类 号：S641.2[农业科学—蔬菜学]