木薯须根、块根韧皮部及其周围薄壁细胞的超微结构观察和功能分析  

Ultrastructures of phloem and its surrounding parenchyma cells of cassava fibrous and tuberous root

作　　者：潘坤[1,2] 聂佩显[3] 卢诚[2] 王文泉[2] 

机构地区：[1]海南大学,海南海口570100 [2]中国热带农业科学院热带生物技术研究所,海南海口570100 [3]山东省果树研究所,山东泰安271000

出　　处：《电子显微学报》2013年第1期73-80,共8页Journal of Chinese Electron Microscopy Society

基　　金：国家重点基础研究发展计划(973计划)(2010CB126600);国家木薯产业技术体系项目(CARS-12)

摘　　要：利用透射电镜技术对木薯初生、次生须根和3个时期的块根韧皮部进行了亚细胞结构的观察,目的在于为其同化物卸载研究提供细胞学证据。结果发现初生须根时期的细胞胞间连丝数量较少,韧皮部和皮层的细胞间间隙较大,特别是薄壁细胞间较明显,多数韧皮部细胞发生质膜内陷等质外体卸载证据。块根时期的伴胞细胞器丰富,伴胞液泡碎片化,胞间连丝数量大增,薄壁细胞内逐渐出现淀粉累积,到成熟期淀粉粒最为密集。同样发生次生生长的次生须根内虽然有少量淀粉累积,但随着其膨大活动的终止,其胞间连丝的密度和初生须根的差别不大。这些结果说明胞间连丝的数量和密度与淀粉的累积有着重要的关系,同样也是其共质体卸载路径的重要证据。The transmission electron microscopy technology was used to investigate the ultrsastructure of cassava（Manihot esculenta Crantz） fibrous and tuberous root.This research aims to provide cytological evidences for cassava phloem unloading.The results show that there are a few plasmodesmata（PD） at the primary fibrous root stage,with bigger intercellular space,plasma membrane invagination and the other characteristics of apoplasmic unloading pathway.Companinon cells of tuberous root often have plenty of organelles and contain heavily fragmented vacuoles.The number of PD increases evidently,and plenty of starch granules are accumulated in the parenchyma cells,and it is the densest in the maturity stage.The starch granule is also accumulated in the secondary fribrous root,but it is very little,which may be due to the break off of its swelling ability.The PD found in this stage is similar to that in the primary fribrous root.It can be concluded that the PD is associated with starch accumulation.

关 键 词：木薯 根 胞间连丝 超微结构 卸载 

分 类 号：S533[农业科学—作物学]