独花兰菌根的初步研究

A preliminary study of Changnienia amoena mycorrhizal fungi

该文对独花兰的菌根结构和真菌类群进行了初步研究,以期填补中国独花兰菌根真菌研究的空白,最终达到保护独花兰种质资源、开发和利用独花兰的目的.实验采用徒手切片,酸性品红乳酚油染色法,在光学显微镜下观察菌根的基本结构,并对独花兰的菌根组织进行真菌分离.独花兰具有典型的兰科植物菌根构造,在光学显微镜下可以观察到菌根真菌从根毛进入根被和外皮层,通过通道细胞侵入到皮层薄壁组织,在皮层薄壁细胞内形成菌丝团.通过两次分离,共得到36个菌株,属于担子菌和有丝孢菌,其中优势种属为镰刀菌属.将16个菌株接种在华石斛组培苗上,有10个菌株对幼苗生长有不同程度的促进作用,其中有1个菌株(DHL--19)处理苗与对照差异达到显著水平(α=0.05),2个菌株(DHL--16、DHL--17)处理苗与对照差异达到极显著水平(α=0.01).在3个接菌处理苗的营养根中均分离获得了原接种菌,切片观察能看到少量菌丝团.因此,DHL--16、DHL--17、DHL--19这3个菌株初步确定是兰科植物的菌根真菌.

Changnienia amoena Chien is a monotypic species and endemic to China. In our experiment, microstructure of mycorrhiza and fungal species of Changnienia amoena were studied. Observations on the microstructure of mycorrhiza of wild Changnienia amoena demonstrate that it has the typical mycorrhizal structure of orchids. Mycorrhizal fungi enter the velamen and exodermis through root hair, invade the cortical tissue by the exodermal passage cells and then form pelotons. Isolation has been carried out twice and 36 strains have been isolated. These belong to the Classes Basidiomycotina and Deuterornycotina ; of these, the superior genus is Fusariurn. Sixteen fungus strains were inoculated to tissue-cultured seedlings of Dendrobium sinense and 10 of them promoted the growth of seedlings at different levels after inoculation. The average height increment of the seedlings inoculated with strain （DHL-19） is significantly higher than that of the control （α = 0.05） and the average height increment of the seedlings inoculated with two fungus strains （DHL-16 and DHL-17） is also significantly higher than that of the control （α= 0.01 ）. The primal strains were re-isolated and a few pelotons were observed from the three treated seedlings. We conclude that DHL-16, DHL-17 and DHL-19 should be used as the mycorrhizal fungi for orchids.