六盘山区幼龄蒙古栎根系共生真菌的分离和鉴定

Isolation and identification of symbiotic fungi in roots of young Quercus mongolica on Liupan Mountain

关键词:  六盘山区, 蒙古栎, 共生真菌, 分离培养, 鉴定

Key words:  Liupan Mountain, Quercus mongolica, symbiotic fungi, isolation and culture, identification

摘要:

为阐明幼龄蒙古栎根系可培养共生真菌的群落结构和动态变化,该文从不同年龄的幼龄蒙古栎(Quercus mongolica)根系分离可培养共生真菌,并通过菌落形态学结合分子生物学的方法对其物种进行鉴定,结果表明:(1)从幼龄蒙古栎根系中分离获得249株真菌,经鉴定隶属于2门5纲7目 8科 15属 18种,其中2种隶属于担子菌门(Basidiomycetes),16种隶属于子囊菌门(Ascomycota)。种水平上,以灰粉无柄盘孢菌(Pezicula pruinosa)分离频率最高,占分离菌株总数的81.93%; 托雷斯氏丛赤壳菌(Dactylonectria torresensis)、强壮土赤壳菌(Ilyonectria robusta)、北美黑盘菌(Atrocalyx nordicus)次之,分别占分离菌株总数的4.02%、2.01%和2.01%。(2)共生真菌种类和数量在不同树龄的蒙古栎中表现出较大差异,其中4～5年生植株分离频率最高(44.98%),依次为3年生植株(29.32%)、2年生植株(19.68%)和1年生植株(6.02%)。综上认为,宁夏六盘山幼龄蒙古栎根系可培养共生真菌种类丰富,随树龄增长其种类和数量增加; 灰粉无柄盘孢菌是六盘山幼龄蒙古栎根系可培养共生真菌的绝对优势物种。该研究结果为进一步挖掘植物共生微生物资源,探索蒙古栎与共生微生物互作在本地逆境的适应机制提供了参考。

Abstract:

In order to elucidate community structures and dynamic changes of culturable symbiotic fungal colony in roots of Quercus mongolica, the symbiotic fungi in roots of young Q. mongolica at different ages were isolated directly. The isolated fungi were identified based on the morphological characteristics of colony and molecular analysis. The results were as follows:(1)A total of 249 fungal strains were isolated from the roots of young Q. mongolica, 18 species belonging to 15 genera, 8 families, 7 orders, 5 classes and 2 phyla were recognized. Among them, two species belonged to Basidiomycetes and 16 species belonged to Ascomycota. Pezicula pruinosa was the species with the highest isolation frequency(81.93%), followed by Dactylonectria torresensis (4.02%), Ilyonectria robusta (2.01%) and Atrocalyx nordicus (2.01%).(2)Significant differences in species and quantities of symbiotic fungi demonstrated in different ages of young Quercus mongolica, with the highest frequency of isolation occurring in the 4-5 years old(44.98%)followed by the triennial(29.32%), biennial(19.68%)and annual(6.02%). To sum up, culturable symbiotic fungi in the roots of young Q. mongolica on Liupan Mountain are highly diverse. Species and quantities of isolates vary at different ages of trees, the diversity increases with the growth of tree, and Pezicula pruinosa is the most dominant culturable symbiotic fungi in roots of young Quercus mongolica. The results provide the reference for further investigating symbiotic fungal resources and exploring the microbial symbiotic mechanism of Q. mongolica in adapting to local environment.