中间锦鸡儿叶表皮微形态的经度格局及其影响因素

Longitude-related Variation in Leaf Epidermal Micro-morphology and Its Influencing Factors in Caragana intermedia

环境因子是影响植物种内变异的主要因素,而叶片是植物体最易受环境影响的器官。为了探究中间锦鸡儿植物叶表皮微形态是否具有经度变异及其影响因素,该研究在内蒙古高原调查了8个中间锦鸡儿种群叶片的气孔密度、气孔指数、表皮毛密度、气孔器长、气孔器宽,并利用回归分析探究其变异程度以及影响因子。结果表明:(1)锦鸡儿上下表皮均被有单细胞非腺毛,角质层粗糙,气孔下陷,为抗旱特征;中间锦鸡儿上表皮气孔密度、气孔指数、表皮毛密度、气孔器长和气孔器宽的均值分别为302.81个/mm2、9.94、204.81个/mm2、11.78μm和5.95μm,而叶片下表皮分别为272.83个/mm2、10.43、187.45个/mm2、12.49μm和6.18μm。(2)中间锦鸡儿叶片的气孔密度与气孔指数随经度的增加而增加,而表皮毛密度随经度的增加却减小。(3)叶片上下表皮的可塑性指数排序均为:表皮毛密度>气孔密度>气孔指数>气孔器宽>气孔器长;中间锦鸡儿的叶表皮主要通过调节表皮毛密度及气孔密度来响应环境的变化,环境因子中日照时数、有效积温、相对湿度、土壤全碳、全磷、全氮含量显著影响叶片表皮的微形态特征。

Environmental factors are the main factors affecting the intra-specific variation of plants,and leaves are the organs most susceptible to the environment.In order to explore whether the leaf epidermal micromorphology of leaf epidermis of plants has longitude variation and its influencing factors,we investigated the stomatal density,stomatal index,epidermal hair density,stomatal apparatus length and stomatal apparatus width of 8 populations of Caragana intermedia in the Inner Mongolia Plateau.The regression analysis is used to explore its degree of variation and impact factors.The results showed that:(1)the epidermis of the Caragana intermedia is covered by single cell non-glandular hair,the stratum corneum is rough,and the stomata are subsided which were the characteristics of drought resistance.The mean(±standard error)of stomatal density,stomatal index,epidermal hair density,stomatal apparatus length and stomatal apparatus width in the upper epidermis of C.intermedia were 302.81 pieces/mm 2,9.94,204.81 pieces/mm 2,11.78μm,5.95μm,and the lower surface of the leaves were 272.83 pieces/mm 2,10.43,187.45 pieces/mm 2,12.49μm and 6.18μm,respectively.(2)The stomatal density and stomatal index increased with the increase of longitude,while the leaf epidermal hair density decreased with the increase of longitude.(3)The plasticity index of the epidermis is:epidermal hair>stomatal density>stomatal index>stomatal apparatus width>stomatal apparatus length.The leaf epidermis of C.intermedia responds to the changes of the environment mainly by adjusting the epidermal hair density and stomatal density.Sunlight hours,effective accumulated temperature,relative humidity,soil total carbon,total phosphorus and total nitrogen contents significantly affected the micromorphological characteristics of leaf epidermis.