Department of Bioscience and Food Production Science, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 8304, Minami-minowa, Nagano 399-4598, Japan.
Mycorrhiza. 2013 May;23(4):303-15. doi: 10.1007/s00572-012-0471-x. Epub 2012 Dec 15.
Amanita caesareoides is a sister species of Amanita caesarea, also known as Caesar's mushroom and one of the most desirable edible mycorrhizal mushrooms. However, cultivation of Caesar's mushrooms has not yet been successful due to the difficulties involved in establishing pure cultures. In this study, we established pure cultures of four Asian Caesar's mushroom species, i.e., A. caesareoides, Amanita javanica, Amanita esculenta, and Amanita similis, which were identified by sequence analysis of their rDNA internal transcribed spacer (ITS) region. Five selected isolates in A. caesareoides, A. javanica, and A. esculenta were tested for ectomycorrhizal syntheses with axenic Pinus densiflora seedlings in vitro. Ectomycorrhizal tips of each fungal isolate tested were observed on pine lateral roots within 5 months of inoculation. Seventeen pine seedlings that formed ectomycorrhizas in vitro with these three Amanita species were acclimatized under non-sterile conditions. Seven months following acclimatization, ectomycorrhizal colonization by A. caesareoides was observed on newly grown root tips, which was confirmed by polymerase chain reaction restriction fragment length polymorphism analysis of the fungal rDNA ITS region. Two other Amanita species also survived during ectomycorrhizal acclimatization. These results suggest that the cultivation of A. caesareoides and its relatives can be attempted through mycorrhizal synthesis using P. densiflora as a host. This is the first report of in vitro mycorrhization of Asian Caesar's mushrooms and their acclimatization under non-sterile conditions.
鹅膏菌 caesareoides 是鹅膏菌 caesarea 的姊妹种，也被称为恺撒蘑菇，是最受欢迎的可食用共生菌菇之一。然而，由于难以建立纯培养物，恺撒蘑菇的栽培尚未成功。在这项研究中，我们通过对其 rDNA 内转录间隔区（ITS）区域的序列分析，建立了四种亚洲恺撒蘑菇物种的纯培养物，即鹅膏菌 caesareoides、鹅膏菌 javanica、鹅膏菌 esculenta 和鹅膏菌 similis。从鹅膏菌 caesareoides、鹅膏菌 javanica 和鹅膏菌 esculenta 中选择了五个选定的分离物，在体外与无菌的赤松幼苗进行外生菌根合成测试。在接种后 5 个月内，观察到每个真菌分离物在松侧根上的外生菌根尖端。在体外与这三种鹅膏菌形成外生菌根的 17 株松苗在非无菌条件下进行驯化。驯化 7 个月后，在新生长的根尖上观察到鹅膏菌 caesareoides 的外生菌根定殖，这通过真菌 rDNA ITS 区域的聚合酶链反应限制性片段长度多态性分析得到了证实。另外两个鹅膏菌物种在共生驯化过程中也存活了下来。这些结果表明，可以通过使用赤松作为宿主进行菌根合成来尝试栽培鹅膏菌 caesareoides 及其亲缘种。这是亚洲恺撒蘑菇的体外菌根化及其在非无菌条件下驯化的首次报道。
