耐盐种质芙蓉菊与6种菊属植物的营养器官解剖结构特征

以菊科芙蓉菊属的芙蓉菊和6种菊属植物(野生种:野菊(天堂寨)、野菊(天柱山)、毛华菊(安徽),品种:‘繁花似锦’‘寒露红’‘毛香玉’)的幼苗为试验材料,以NaCl浓度为200 mmol·L~(-1)的Hoagland营养液进行盐胁迫处理,在盐胁迫0、5、10、15 d分别取各材料的根、茎、叶,制作石蜡切片后用光学显微镜观察并测量其解剖结构特征值。结果显示:芙蓉菊为等面叶而6种菊属植物均为异面叶,芙蓉菊叶肉栅栏组织较发达,且在盐胁迫下栅栏组织变疏松,细胞间隙增多;芙蓉菊相对6种菊属植物其根与茎中的维管组织更为发达,对水分的输导能力更强。芙蓉菊在盐处理15 d后仍能保持根、茎、叶解剖结构的完整,而6种菊属植物的解剖结构从盐胁迫5 d开始就出现了不同程度的细胞解体和组织损坏,且叶和根相对于茎受到的盐害影响更大。盐胁迫下,芙蓉菊叶片中的栅栏组织厚度/叶厚、茎中的皮层厚度/茎半径、根中的中柱直径/根直径随胁迫时间延长而升高,同时茎和根中具有发达的维管组织,明显区别于6种菊属植物,都是其应对盐胁迫的积极响应,推测是其具有耐盐性的重要原因。

Anatomical Structure of Salt-tolerant Crossostephium chinensis and Six Species of Chrysanthemum

We took Crossostephium chinensis and six species of Chrysanthemum as experimental materials including three wild species,C.indicum (Tiantangzhai),C.indicum (Tianzhushan) and C.vestitum (Anhui),and three varieties,C.morifolium ‘ Fanhuasijing',C.morifolium ‘ Hanluhong',and C.morifolium ‘ Maoxiangyu'.The seedlings were treated with Hoagland solution containing 200 mM NaC1.The roots,stems and leaves of each material were collected at 0,5 th,10 th,and 15 th day after salt stress,respectively.Mter making paraffin section,the anatomical features were observed and measured with an optical microscope.The leaf of C.chinensis was isolateral leaf while those of the other six species were bifacial leaves.The palisade tissue of C.chinensis was more developed,and the palisade tissue became loose under the salt stress,as well as the intercellular space increased.The vascular tissues of C.chinensis were more developed in roots and stems compared with six species of Chrysanthemum,and had stronger capacity of water transportation.The anatomical structure of root,stem and leaf of C.chinensis remained intact after 15-d salt treatment,and the cell dissociation and tissue damage of six species of Chrysanthemum appeared since the 5 th day,and the leaves and roots of them were more affected under salt stress than stems.Many features of C.chinensis were increased under salt stress including the ratio of palisade tissue in leaves,cortex/stalk radius in stem and stele/root diameter in root,which were significantly different from those in six species of Chrysanthemum,as well as the more developed vascular tissues in stem and root.All the anatomical structures are positive responses of C.chinensis to salt stress,and will be an important reason for its salt tolerance.