Lalaymia Ismahen, Declerck Stéphane, Naveau Françoise, Cranenbrouck Sylvie
Earth and Life Institute, Applied Microbiology, Mycology, Université catholique de Louvain, Croix du Sud 2, bte L7.05.06, 1348, Louvain-la-Neuve, Belgium.
Mycorrhiza. 2014 Apr;24(3):233-7. doi: 10.1007/s00572-013-0525-8. Epub 2013 Sep 27.
Long-term maintenance of arbuscular mycorrhizal fungi (AMF) by in vitro or in vivo subcultivation is often expensive and time-consuming and could present the risk of contaminations and possibly morphological, physiological, and genetic variations over time. Recently, in vitro produced AMF isolates belonging to the genus Rhizophagus were successfully cryopreserved at -130 °C following encapsulation-drying. Here, this method was tested on 12 single species cultures belonging to six different genera (i.e., Rhizophagus, Glomus, Claroideoglomus, Septoglomus, Paraglomus, and Gigaspora) produced in vitro or in vivo. Their viability was estimated, after 1 month of cryopreservation at -130 °C, by the percentage of potentially infective beads (i.e., the percentage of beads that contained at least one germinated propagule) for the in vitro produced species and the percentage of infective beads (i.e., the percentage of beads that contained at least one propagule able to colonize a new host plant in pot culture) for the in vivo produced species. With the exception of Gigaspora sp. MUCL 52331 and Septoglomus constrictus PER 7.2, no significant differences were observed in the viability of the single species cultures before and after cryopreservation. These results, thus, demonstrated the suitability of the cryopreservation method by encapsulation-drying for AMF species belonging to different genera and produced in vitro or in vivo. This method opens the door to the long-term preservation at ultra-low temperature of a large number of AMF species and for the preservation of species that are still recalcitrant to in vitro cultivation.
通过体外或体内继代培养对丛枝菌根真菌（AMF）进行长期维持通常成本高昂且耗时，并且可能存在污染风险，随着时间的推移还可能出现形态、生理和遗传变异。最近，属于根内球囊霉属的体外产生的AMF分离物在包囊干燥后于-130°C成功冷冻保存。在此，该方法在体外或体内产生的属于六个不同属（即根内球囊霉属、球囊霉属、明球囊霉属、硬囊霉属、类球囊霉属和巨孢囊霉属）的12种单物种培养物上进行了测试。在-130°C冷冻保存1个月后，通过体外产生的物种中潜在感染性珠粒的百分比（即包含至少一个萌发繁殖体的珠粒的百分比）和体内产生的物种中感染性珠粒的百分比（即包含至少一个能够在盆栽培养中定殖新宿主植物的繁殖体的珠粒的百分比）来估计它们的活力。除了巨孢囊霉属MUCL 52331和硬囊霉属PER 7.2外，冷冻保存前后单物种培养物的活力没有观察到显著差异。因此，这些结果证明了包囊干燥冷冻保存方法适用于体外或体内产生的不同属的AMF物种。该方法为大量AMF物种的超低温长期保存以及对仍难以进行体外培养的物种的保存打开了大门。
