持续弱光胁迫对马铃薯苗期生长和光合特性的影响  

Effects of Sustained Weak Light on Seedling Growth and Photosynthetic Characteristics of Potato Seedlings

作　　者：秦玉芝[1] 邢铮[1] 邹剑锋[2] 何长征[1] 李炎林[1] 熊兴耀[1,3] 

机构地区：[1]湖南农业大学园艺园林学院,长沙410128 [2]湖南农业大学分析测试中心,长沙410128 [3]中国农业科学院蔬菜花卉研究所,北京100081

出　　处：《中国农业科学》2014年第3期537-545,共9页Scientia Agricultura Sinica

基　　金："十二五"农村领域国家科技计划课题(2012BAD02B05-8);农业部马铃薯产业技术体系(CARS-10-P19);公益性行业(农业)专项(201203096)

摘　　要：【目的】探讨持续弱光对马铃薯幼苗光合生理特性的影响,进行不同基因型对弱光适应性差异的植物学与细胞学性状的系统研究,为马铃薯耐弱光遗传资源的筛选和利用提供依据。【方法】以马铃薯原始栽培种Yan(Solanum tuberosum subsp.andigena var.yanacochense)和普通栽培品种Favorita(Solanum tuberosum)为供试材料,选用50 g马铃薯块茎播种,进行基质盆栽,萌芽后用人工气候箱进行50μmol·m-2·s-1的持续弱光处理(对照光强为350μmol·m-2·s-1)。1个月后分析测定各处理的生长状况;采用LI-COR 6400便携式光合作用仪测定功能叶片的净光合速率、光合曲线参数、CO2曲线参数、叶绿素含量;功能叶片主脉两侧切取大小1—2 mm见方小块,处理后用JEM-1200EX型电镜扫描观察叶片气孔并照相,分析统计单位面积气孔数量、测量气孔长度与宽;功能叶片经前处理后用LKB-5型超薄切片机切片,醋酸铀-柠檬酸铅双重染色,JGE-1200EX型透射电镜观察叶绿体超微结构、测量并照相。【结果】苗期持续弱光处理使马铃薯Favorita植株明显徒长,叶片变小变薄,但枝叶分化不受影响;原始栽培种Yan则枝叶分化困难,处理过程中生长缓慢,处理后加强环境光照强度亦无法恢复其生长速度与长势;持续弱光处理使两种基因型马铃薯叶片光作用的表观量子效率(AQE)、光合作用饱和点(LSP)、叶片最大净光合速率(Pnmax)、CO2饱和点(CSP)、叶绿素含量降低;表观羧化率(EC)、CO2补偿点(CCP)上升;Favorita的光补偿点(LCP)、表观羧化率(EC)下降;Yan的光补偿点(LCP)上升,表观羧化率(EC),CO2饱和点(CSP)与对照差异不显著。长期弱光胁迫使马铃薯叶片气孔密度,叶绿体数量下降。Favorita的叶绿体基粒数、基粒片层数含量升高,Yan的叶绿体基粒片层数不增反降。【结论】不同基因型枝叶分化对光的敏感性不同,差异明显。环境光照不足,敏感基因型的发育与�【Objective】 The aim of this study was to investigate the effects of sustained weak light on growing conditions and photosynthetic characteristics of potato leaves at the seedling stage and to offer a theoretical basis for screening and utilization of new resistant potato resources to weak light.【Method】 The original cultivated potato Yan （S. tuberosum subsp. andigena var. yanacochense） and cultivated potato Favorita （S. tuberosum） were grown in a growth chamber at 50 μmol·m-2·s-1 and 350 μmol·m-2·s-1 light, respectively, using potato tuber （50 g） growing in medium. After 1 month treatment, the growth of the test materials was measured. Plant phenotype, the chlorophyll content, net photosynthetic rate, photosynthetic curve, the CO2 response curve were tested by LI-COR 6400 portable photosynthesis system. The stomatal morphological characters were measured using JEM-1200EX scanning electron micrography. The ultrastructure of chloroplast was observed by transmission electron microscope using the blade section after uranium acetate-citrate double staining.【Result】There was a difference between the treatment and the control in leaf size, morphology of plant. Favorita had weak vigour, slender seedling with smaller pale green foliage. Foliage and branch induction of Yan were very difficult and grew extremely slowly in or after treatment. Sustained light treatment significantly reduced the apparent quantum yield （AQE）, light saturation point （LSP）, maximum net photosynthetic rate （Pnmax）, CO2 saturation concentration （CSP）, and the chlorophyll content efficiency, and improved apparent carboxylation rate （EC）, and CO2 compensation concentration （CCP） simultaneously. The light compensation point （LCP） of Yan was activated in the treatment. While the LCP and EC of Favorita were reverse. The EC, CSP of Yan had no difference between the treatment and the control. Growing under weak light, the stomatal density, chloroplast number declined. The numbers of grana and grana

关 键 词：马铃薯 苗期 弱光 光合特性 叶绿体超微结构 气孔 

分 类 号：S532[农业科学—作物学]