PDF(Pubmed)
Abstract：
Taxonomic identification of arbuscular mycorrhizal (AM) fungal spores extracted directly from the field is sometimes difficult because spores are often degraded or parasitized by other organisms. Single-spore inoculation of a suitable host plant allows for establishing monosporic cultures of AM fungi. This study aimed to propagate AM fungal spores isolated from maize soil using single spores for morphological characterization. First, trap cultures were established to trigger the sporulation of AM fungal species. Second, trap cultures were established with individual morphotypes by picking up only one spore under a dissecting microscope and transferring it to a small triangle of sterilized filter paper, which was then carefully inoculated below a root from germinated sorghum seeds in each pot and covered with a sterile substrate. All pots were placed in sunbags and maintained in a plant growth room for 120 days. Spores obtained from single spore trap cultures from each treatment, maize after oats (MO), maize after maize (MM), maize after peas (MP), and maize after soybean (MS), were extracted using the sieving method. Healthy spores were selected for morphological analysis. Direct PCR was conducted by crushing spores in RNAlater and applying three sets of primer pairs: ITS1 × ITS4, NS31 × AML2, and SSUmcf and LSUmBr. Nucleotide sequences obtained from Sanger sequencing were aligned on MEGA X. The phylogenetic tree showed that the closest neighbors of the propagated AM fungal species belonged to the genera Claroideoglomus, Funneliformis, Gigaspora, Paraglomus, and Rhizophagus. The morphological characteristics were compared to the descriptive features of described species posted on the INVAM website, and they included Acaulospora cavernata, Diversispora spurca, Funneliformis geosporus, Funneliformis mosseae, Gigaspora clarus, Gigaspora margarita, Glomus macrosporum, Paraglomus occultum, and Rhizophagus intraradices. These findings can provide a great contribution to crop productivity and sustainable management of the agricultural ecosystem. Also, the isolate analyzed could be grouped into efficient promoters of growth and mycorrhization of maize independent of their geographical location.
摘要：
从田间直接提取的丛枝菌根（AM）真菌孢子的分类学鉴定有时很困难，因为孢子经常被其他生物降解或寄生。合适的寄主植物的单孢子接种允许建立AM真菌的单孢培养物。本研究旨在使用单个孢子进行形态表征，繁殖从玉米土壤中分离出的AM真菌孢子。首先,建立陷阱培养物以触发AM真菌物种的孢子形成。第二,通过在解剖显微镜下只拾取一个孢子并将其转移到无菌滤纸的小三角形上，用单个形态型建立了陷阱培养物，然后在每个盆中从发芽的高粱种子中小心地接种根下，并用无菌基质覆盖。将所有盆置于日光浴袋中并在植物生长室中保持120天。从每种处理的单孢子陷阱培养物中获得的孢子，燕麦后玉米（MO），玉米后玉米（MM），豌豆后的玉米（MP），和大豆后玉米(MS)，使用筛分法提取。选择健康孢子进行形态学分析。通过在RNAlater中压碎孢子并应用三组引物对进行直接PCR：ITS1×ITS4，NS31×AML2以及SSUmcf和LSUmBr。从Sanger测序获得的核苷酸序列在MEGAX上进行了比对。系统发育树显示，繁殖的AM真菌物种的最近邻居属于Claroideoglomus属，真菌,Gigaspora,Paraglomus,和根虫。将形态特征与INVAM网站上所描述物种的描述性特征进行了比较，其中包括洞穴状孢子虫，SpurcaDiversispora,异形真菌，真菌，GigasporaClarus,Gigasporamargarita,大孢子球虫,眼周副球，和根瘤菌内。这些发现可以为作物生产力和农业生态系统的可持续管理做出巨大贡献。此外，分析的分离株可以分为玉米生长和菌根化的有效启动子，而与它们的地理位置无关。
