作　　者： (李俊）; (杨玉皎）; (王文丽）; (郭华春）;

机构地区： 云南农业大学农学与生物技术学院,昆明650201

出　　处： 《生态学报》 2017年第16期5368-5381,共14页

摘　　要： 叶片作为植物进行光合作用的主要器官,在长期进化过程中形成了对不同光照环境条件的形态可塑性和相应的适应机制,以保证植物能在变化的、非适宜环境下的生存与繁衍。随着大气臭氧层衰减引起地表UV-B辐射增强,其对植物叶片结构和光合作用的影响显著,但这种气候变化趋势对马铃薯叶片形态结构、光合作用的影响尚不明确。设置增强UV-B辐射2.5 kJm^(-2)d^(-1)(T1)、5.0 kJm^(-2)d^(-1)(T2)、自然光(CK)3个处理,以6个马铃薯品种(系)为材料,研究增强辐射对不同基因型马铃薯叶片结构和光合参数的影响。结果表明:增强的UV-B辐射使马铃薯叶片解剖结构不同程度增厚,叶片厚度增加;叶片气孔和非腺毛的密度增加明显,腺毛有增多倾向。扫描电镜显示处理后的近轴面叶片角质层厚度增加,蜡质晶体增多,但表皮细胞变小且失水萎缩,细胞轮廓模糊;气孔、腺毛及非腺毛附属结构受胁迫影响呈萎缩状态。透射电镜显示处理后的叶肉细胞中基粒类囊体肿胀,结构层次紊乱,胁迫引起细胞质壁分离,细胞壁扭曲并有较多的沉淀物;部分品种过氧化物酶体可见清晰的过氧化氢酶晶体。叶片缩小增厚、腺毛增多、角质层和蜡质增厚、胞内积累过氧化氢酶的形态适应和生理响应并未能有效减少UV-B辐射对光合参数和光合效率的影响,合作88、丽薯6号、师大6号的净光合速率、气孔导度等参数均受到抑制,光能利用效率明显降低,属于UV-B辐射敏感型品种;剑川红21-3、21-1和转心乌3个品种(系)的相关光合特性几乎不受影响,显示云南地方品种具有较强的UV-B辐射耐受性,有待于进一步从生理生化和分子水平探究更多的适应机制。 Plant leaves are important organs due to their autotrophism, and plants have evolved diversified leaf protection mechanisms to ensure their survival under unstable and sub-optimal environmental conditions. Leaf morphological plasticity and alterations to leaf structure are commonly observed following exposure to different light illuminations. There has been extensive research on the enhanced UV-B radiation increase at the earth＇s surface due to ozone and its deleterious effects to leaf structure and crop photosynthesis, but few studies have investigated the effect on potato. In this study, six potato varieties （lines） were grown under 0, 2.5, and 5.0 kJ m-2 d-1 of biologically effective UV-B radiation in pots under field conditions to evaluate the general effects of enhanced UV-B radiation on the leaf structure and photosynthesis of different potato genotypes. The results showed that the leaves of most varieties became incrassate to varying degrees, which, with the exception of one variety, led to an increase in total leaf thickness. The stomata, non-glandular and glandular trichomedensities significantly increased. The thickness of the cuticle and wax layer on the adaxial surface appeared to have obvious incrassation based on the scanning electron microscope images, and all these morphological responses have been widely recognized as effective ways of improving tolerance or resistance to UV-B radiation. However, the inhibitive and damaging effects of elevated UV-B radiation to epidermal cells have also been observed. These include smaller cell size, an undefined cellular profile, and an atrophic shape due to dehydration. Constitutive stomata and trichome cells showed similar symptoms. The transmission electron microscope images showed that grana thylakoids in mesophyll cells were swollen in shape and the layers had a disordered appearance. Induced plasmolysis and sediments on twisted cell walls were observed in some cells under UV-B radiation stress. In addition, some catalase paracrystalline inclusions we

关 键 词： 马铃薯 辐射 形态适应 地方品种