玉米全蚀病病菌侵染过程及其毒素的初步研究  

Preliminary Studies On Infection Process and Toxin of Corn Take-all Fungs

作　　者：宋蒙娜 李秀琴[1] 姚建民[1] 

机构地区：[1]沈阳农业大学

出　　处：《玉米科学》1995年第A01期64-67,共4页Journal of Maize Sciences

摘　　要：玉米全蚀病菌（Ｇ．ｇ．ｍ）浸染寄主初期，匍匐菌丝在玉米根表纵向生长，然后产生侵染菌丝穿透根表皮向深层扩展，并形成大量附着枝。寄主根细胞对病菌穿透的反应是形成封闭的木质管鞘包围侵染菌丝。管鞘内菌丝穿透管鞘末端，向更深层细胞扩展，并重复同样的过程。病菌能侵染中柱，使中柱变褐坏死，但未见菌丝。Runner hyphae of corn take-all fungus (G. g. m)grow onto the surface ofcorn roots in early infection stage, then produce infection hyphae which may penetratethe epidermis of corn roots and many hyphopodia. In response to penetration, the hostcell produce closed lignitubers around the infection hyphae. The in fetion hyphae growthrough the apices of the lignitubers and proceed to the next cell layer,where the sameprocess is repeated. G. g. m's attack can reach the stele of root and then lead to destruction of it,and death. But the hyphae were not found in stele.G. g. m. can produce a toxin. The experiments of toxin-producing condtion showthat if G. g. m is developed on solid corn ground-grain medium in dark,at 25℃ and pH7. 2,after 40 days,there will be a toxin-producing peak. As time extend,the yield of toxin dose not challge.The toxin was extracted with methanol,and purified by absorption chromatographythrongh active carbon column with methanol as eluant. Results from bioassay suggestedthat the toxin could inhibit obviusly the growth of corn radicel,blight young seed rootsas well as excised or nonexcised leaves,and damage the ultrastructure such as cell wall,cell membrane, mitochoclia and chloroplast of leaf and root cell. Vivotoxin whichproduced by G. g. m can also inhibit the growth of corn radicel.Preliminary identification showed that the initial purified toxin contains carbonhydrate and protein,protein was the main part. The analysis of composition showed thatthere were 18 kinds of amino acid,and glutamic acid was the main kind. The proportionof ackidity amino acid was higher than that of basicity amino acid.

关 键 词：玉米 全蚀病菌 病菌侵染 毒素 

分 类 号：S435.131.4[农业科学—农业昆虫与害虫防治]