矿质元素对北虫草继代培养中菌落形态的影响

Effect of Mineral Elements on Colony Types of Cordyceps militaris in Subculturing

研究矿质元素对北虫草继代培养中菌落类型的影响,旨在探讨优型菌落保持代数最长的矿质元素配方。采用正交试验,将北虫草优良菌株L20在不同矿质元素培养基上进行12次继代培养。结果表明:菌株L20在不同培养基中继代培养后形成7种菌落类型,有子实体形成能力的菌落为Ⅰ、Ⅱ、Ⅲ、Ⅴ型,其中Ⅰ型菌落产量最高,Ⅲ型居中,Ⅱ型最低,Ⅴ型形成子实体均为畸形;Ⅳ、Ⅵ、Ⅶ型无子实体形成能力。各类型菌落在不同培养基中的分布规律是:子实体产量较高的Ⅰ、Ⅲ型菌落主要分布在前10代;产量较低的Ⅱ型菌落分布在前4代;子实体为畸形的Ⅴ型和无子实体形成能力的Ⅳ、Ⅵ、Ⅶ型菌落主要分布在4代以后。保持优型菌落——Ⅰ型最为稳定的矿质元素配方为1.0g·L-1K+、0g·L-1Mg2+、0.02g·L-1Ca2+、0μg·L-1Mn2+、250μg·L-1或375μg·L-1Zn2+。可见,Ⅰ型菌落产量最高,为北虫草优型菌落。其主要形态特征为:菌落颜色较深呈橘黄色、菌丝气生性中等、菌落质地为致密绒毛状,有同心纹、在继代培养中有角变现象。1.0g·L-1K+、0.02g·L-1Ca2+、250μg·L-1或375μg·L-1Zn2+对Ⅰ型菌落起到延缓退化的作用,而Mn2+、Mg2+会促进其退化。

The effect of mineral elements on colony types of Cordyceps mi1itaris in subculturing was reaseached in order to explore a most suitable mineral elements formulation for maintainning the stablility of the excellent colony type.A good strain, named L20,was subcultured on different media with different mineral elements for twelve times by orthogonal experimental method.The results showed that there were seven colony types of L20 after subcultured,among which typeⅠ,Ⅱ,ⅢandⅤ could form fruit-body,Ⅳ,ⅥandⅦ,however,could not.TypeⅠhad the highest yield of fruit-body,Ⅲin the middle,Ⅱthe lowest;Ⅴhad all abnormal fruit-body.Distribution patterns of colony types in different media were as follow：typeⅠandⅢ mainly in 110 generations;typeⅡin 14 generations;typeⅤ,Ⅳ,ⅥandⅦmainly after 4 generation.TypeⅠwas the best kind of colony type and the medium contained K＋（1.0g·L-1）,Mg2＋（0g·L-1）,Ca2＋（0.02g·L-1）,Mn2＋（0μg·L-1）,Zn2＋（250μg·L-1 or 375μg·L-1）and could maintain typeⅠmore stable.The main morphological features of typeⅠwere saffron yellow colony color; aerial of hyphae at middle level,dense floss colony texture with concentric circle;and sector in subculturing.The degradation of typeⅠcolony could be delayed by K＋（1.0 g·L-1）,Ca2＋（0.02g·L-1）,Zn2＋（250μg·L-1or 375μg·L-1）and accelerated by Mn2＋,Mg2＋.