Plants establish symbiosis with arbuscular mycorrhizal fungi (AMFs) for nutrient exchange and also for tolerance to contaminants. During February 2019, soil and rhizosphere samples of Laguncularia racemosa (Lr) and Avicennia germinans (Ag) were collected on 4.15 hectares of a mangrove forest established in Histosol affected since 1967 by chronic oil spill in southeastern Mexico. The site was divided into four zones based on the amounts of total hydrocarbons of weathered petroleum (THWPs) accumulated in the soil for half a century. The abundance of intraradical propagules and the colonization structure of the AMFs in the roots of the two mangrove species were compared. The density of phosphate-solubilizing bacteria (PSBs) in soil and rhizosphere samples was also evaluated. The degraded oil stimulated the amount of PSBs in Lr but not in Ag. AMF biodiversity was lower in the Ag root; however, spore abundance was higher. We found abundant spores of Glomus claroideum and Diversispora aurantium in tertiary and quaternary roots of the Ag in soils contaminated with 48462 mg of THWPs. This study provides evidence of the presence and abundance of intraradical propagules in different types of roots, which may be an alternative that contributes to the understanding of oil dissipation and in future applications for the restoration of degraded ecosystems.

植物与丛枝菌根真菌（AMF）建立共生关系，以交换养分并耐受污染物。在2019年2月，土壤和根际样品Laguncularia鹃（LR）和白骨germinans（Ag）收集自1967年以来在墨西哥东南部长期漏油影响的Histosol建立的4.15公顷红树林。根据半个世纪以来土壤中累积的风化石油（THWPs）的总碳氢化合物的数量，该地点分为四个区域。比较了两种红树林物种的根中根际内繁殖体的丰度和AMF的定殖结构。还评估了土壤和根际样品中溶解磷酸盐的细菌（PSB）的密度。降解的油刺激了Lr中的PSB含量，但刺激了Ag中的含量。Ag根部的AMF生物多样性较低；但是，孢子丰度较高。我们发现了Glomus claroideum和Diversispora aurantium的大量孢子在被48462 mg THWPs污染的土壤中，Ag的第三级和第四级根系中。这项研究提供了不同根系中根际内繁殖体的存在和丰富的证据，这可能是有助于理解油耗以及在恢复退化的生态系统的未来应用中的替代选择。