茯苓太空诱变菌株生物特性与品质系统研究

Systematic Study on Biological Characteristics and Quality of Fuling (Poria cocos) Strain Mutagenized in Space

茯苓是我国大宗药食两用资源,对搭载“神舟十号”太空诱变育种的太空10号茯苓菌株进行生物特性研究和品质评价,探讨其推广应用的可能性。采用分子生物技术和大田栽培实验,对比菌株茯苓太空10号与湘靖28、5.78,研究其表观性状、显微结构、基因序列、拮抗反应、生长速度、结苓情况、生物转化率、薄层色谱和浸出物含量指标。结果显示,菌株太空10号菌丝细长,未见锁状联合,菌丝体外观均呈白色绒毛状,菌核呈类球形、椭圆形或不规则的块状,冷冻电镜扫描可见菌核呈柱状凸起的团块。太空10号与湘靖28和5.78的ITS、LSU、TEF1-α基因序列相似性达100%,进化树聚类为一支。太空10号与湘靖28拮抗较弱,与5.78拮抗明显。在20℃条件下,太空10号呈现出较快的生长速度。大田栽培实验显示,太空10号的菌核生物转化率较优,鲜重转化率达23.25%,干重转化率达11.28%,且其薄层色谱和水溶性浸出物、醇溶性浸出物含量均符合药典标准。研究表明经过诱变的菌株太空10号茯苓所属基源和菌核性状符合茯苓药材要求,生长情况良好,品质优良,具有推广应用潜力。

Fuling, or Indian bread, or Tuckahoe(Poria cocos) is an important staple medicinal and edible fungal resource in China. The biological characteristics and quality evaluation of P. cocos mutagenic strain MBIS No.10, mutagenized in space carried by spacecraft "Shenzhou 10", was conducted to explore the possibility of extensive application. Molecular biotechnology and field cultivation experiments were adopted to compare P. cocos MBIS No.10, Xiangjing 28 and 5.78 strains to investigate their performance traits, microscopic structure, gene sequence, antagonistic response, growth rate, sclerotium forming condition, biotransformation rate, thin layer chromatography and content of extractive index. The results showed that hyphae of the MBIS No.10 strain are slender, without clamp connection. The appearance of the mycelium is white villi, and the sclerotia are spherical, oval or irregular lump. The cryo-electron microscope scan showed that the sclerotium has a columnar convex lump. The sequence similarity of ITS, LSU and TEF1-α among MBIS No. 10, Xiangjing 28, and 5.78 strains is 100%, and they are clustered into one branch in the phylogenetic tree. MBIS No 10 and Xiangjing 28 were weakly antagonistic, and 5.78 was obviously antagonistic with MBIS No 10. Under the condition at 20 ℃, MBIS No.10 strain assumed a comparatively faster growth rate. Field cultivation experiments showed that the sclerotium biotransformation rate of MBIS No.10 is more excellent, with a fresh weight conversion rate as high as 23.25% and a dry weight conversion rate as high as 11.28%. Its thin layer chromatography, water-soluble extracts, alcohol-soluble extracts contents were in line with pharmacopoeia standards. The research shows that the species origin and sclerotia characteristics of the mutagenized strain MBIS No.10 meet the requirements of Poria cocos as medicinal material. The growth and quality are excellent, and it has the potential for extensive application.