内生真菌在禾草体内的分布特征

Distribution characteristics of Epichloё endophyte in gramineous grasses

以醉马草(Achnatherum inebrians)、中华羊茅(Festuca sinensis)、野大麦(Hordeum brevisubulatum)及披碱草(Elymus dahuricus)为研究材料,通过光学显微镜和透射电子显微镜对植株茎节间、叶鞘、叶片及种子进行观察,发现Epichloё内生真菌普遍存在于茎节间、叶鞘、叶片及种子中。菌丝体在4种禾草体内分布特点较为相似,茎节间菌丝体分布密集,叶鞘次之,叶片中则分布较为稀疏,均沿细胞伸长方向纵向生长,呈直线或弯曲状,细长无分支;对种子的观察发现,除在醉马草糊粉层内很难观察到菌丝体外,Epichloё内生真菌普遍存在于中华羊茅、野大麦及披碱草的糊粉层中,4种禾草的种皮及胚中均明显的观察到了菌丝体的存在。

In the present study,the internodal region of stems,sheaths,blades and seeds of four different species including Achnatheru inebrians,Festuca sinensis,Hordeum brevisubulatum and Elymus dahuricus were observed by the light microscopy and transmission electron microscopy. The results showed that Epichloё endophyte distributed in all these four tested tissues in each species. The endophyte distribution characteristics in these 4 different species were similar,which included hyphae densely distribution in the internodal region of stems and followed by sheaths whereas sparse distribution in blades. The hyphae were straight or curved and long,thin and unbranched and longitudinally growth in the cell extension direction. In the seeds,Epichloё endophyte hyphae were widely distributed in the aleurone layers of F. sinensis,H. brevisubulatum and E. dahuricus,however,it was sparely distributed in the aleurone layers of A. inebrians. Epichloё endophyte hyphae were also observed in the seed coats and embryos of these four gramineous grasses.