新疆短命植物东方旱麦草和独行菜C4相关结构的初步研究

短命植物的快速生长及高光效特性使它们能在早春萌发后较短时间内完成生活史并获得大量种子.为探讨高光效产生的内在原因,研究利用树脂半超薄与超薄切片技术对东方旱麦草和独行菜叶片显微及超微结构进行观察,并对维管束相关参数进行了统计分析,结果显示:(1)东方旱麦草显微结构具有类"花环"结构,维管束密度介于C3、C4对照之间,鞘细胞中的叶绿体多数离心分布且数量接近C4植物;超微结构显示其鞘细胞叶绿体的基粒与片层结构与叶肉细胞不同,但又与C4植物存在一定差异.(2)独行菜维管束有类"花环"结构,维管束密度大于C3对照并存在极显著差异,鞘细胞中叶绿体多数离心分布;超微结构显示叶绿体基粒与片层没有叶肉细胞发达.以上研究结果初步说明东方旱麦草和独行菜的解剖结构特点均介于C3、C4植物之间而接近C4植物.

Studies on the C4-related Structures of Two Ephemerals-Eremopyrum orientale (L.) and Lepidium apetalum Willd in Xinjiang

Fast growth and high photosynthetic efficiency of the ephemeral plants provide them with a large quantity of seeds when they complete their life cycles in a short time after germination.The leaf semi-ultra thin and ultra-thin cross sections of E.orientale and L.apetalum were employed to explore the anatomic structures related to the high photosynthetic efficiency.Results of observation and parameter analysis showed:(1)The microstructure of E.orientale had apparent Kranz-like bundle sheath anatomy;the vascular density of leaf was higher than that of C3 but lower than that of C4 plants;most of the chloroplasts in the bundle sheath cells(BSC) displayed centrifugal location pattern,which was similar to C4 plant.The ultrafine structure revealed that the chloroplasts in BSC was different from those in mesophyll cells(MC) and the structure and quantity of grana and lamella,however,neither of them was totally identical with the C4 plant.(2) The microstructure of L.apetalum also had Kranz-like anatomy,its vascular density was significantly higher than that of C3 plant(P+<0.01),most of the chloroplasts in the BSC were distributed centrifugally,and their grana and lamella were less developed than those in MC.The above results illuminated that the anatomic structure of the two ephemerals were characterized between the C3 and C4 plants,but more closely related to C4 plant.