榆耳有性结构及生活史的研究

本文通过电镜扫描、石腊切片及用苏木精染色法和DAPI荧光染色,对榆耳子实体有性结构进行观察,证实榆耳子实体菌盖结构分三层:上表层为毛层,表面着生有排列较密集顶端游离的菌丝,它们相互粘连呈菌丝束;中间层为髓部,由较疏松而相互交织在一起的薄壁菌丝组成,菌丝间充满胶质物质;下表层为子实层,表面起伏不平,呈不规则的疣状突起,上面着生担子和囊状体,担子无隔膜棍棒形,外表有不规则的网状纹饰,其顶部着生4个瓶梗状小梗,每个小梗上着生1个椭圆形或腊肠形担孢子,大小为2.5—3.0×6.0—6.5μm,担孢子表面有不规则的网状纹饰结构。在担子间的囊状体为长圆柱形或圆锥形,表面有较密的不规则的网状纹饰。 榆耳有性生殖为异宗配合。绝大多数担孢子含一个细胞核,很少数担孢子含两个细胞核。孢子萌发为一端萌发,也有少数为两端萌发。初生菌丝单核,不能形成子实体,当两种不同遗传性的交配型的初生菌丝结合后,形成具有锁状联合结构的双核菌丝,并可发育成子实体。榆耳具有典型减数分裂过程,不具有减数分裂后核分裂行为,四个子核分别进入四个担孢子内。 在初生菌丝或次生菌丝上,均可产生间生的或顶生的厚垣孢子。经过温度、光照和紫外线照射的诱发,均未发现有其它类型的无性孢子产生。因此,榆耳菌的生活史和大多数担子

STUDIES ON SEXUAL STRUCTURES AND LIFE CYCLE OF GLOESTEREUM INCARNATUM

The sexual structures of Gloestereum incornatum S. Ito et Imai were investigated by means of SEM, paraffin section and nuclei staining techniques of haematoxylin and DAPI. The cross sections of a piece of lamella revealed that it consists of three layers: hair layer, trama and hymenium, Hairs on the upper surface of the pileus are long, dense and forming innumerable bundles of hairs. Trama in the middle of lamella is composed of loosely interwoven hyphae. The lower surface of hymenium is with warts on it. The club-shaped basidia have no septa and have relicula on it. Four basidiospores from sterigmata are clavate or allantoid and have relicula on it. Cystidia are cylindrical or cambiform, some of them are projecting beyond the basidia. G. incarnatum are heterothallic. Most of the basidiospores are uninucleate. Primary mycelia are also uninucleate, and cannot develop fruiting body. Clamp connections form only when two compatible monokaryotic hyphae fuse. G. incarna-tum has typical meiosis and no postmeiosis division. Chlamydospores are found either in primary mycelia or secondarmycelia. Their formation can be either intercalary or terminal. No other asexual spores are found even after inducing with temperature, light and UV. So it is belifed that G. incarnatum has no asexual cycle, the life cycle of it is completed by sexual generation.