Kobae Yoshihiro, Ohtomo Ryo, Morimoto Sho, Sato Daiki, Nakagawa Tomomi, Oka Norikuni, Sato Shusei
Laboratory of Crop Nutrition, Department of Sustainable Agriculture, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan.
Hokkaido Agricultural Research Center, National Agriculture and Food Research Organization (NARO), 1 Hitsujigaoka, Toyohira, Sapporo, Hokkaido 062-8555, Japan.
Plants (Basel). 2019 May 30;8(6):142. doi: 10.3390/plants8060142.
Arbuscular mycorrhizal fungi (AMF) are a group of soil microorganisms that establish symbioses with most land plant species. "Root trap culture" generally has been used for isolating a single regenerated spore in order to establish a monospecific, native AMF line. Roots may be co-colonized with multiple AMF species; however, only a small portion of AMF within roots sporulate, and do so only under certain conditions. In this study, we tested whether young thalli (<2 mm) of the liverwort harbour monospecific AMF, and can be used as a vegetative inoculant line. When gemmae were co-cultivated with roots obtained from the field, the young thalli were infected by AMF via rhizoids and formed arbuscules after 18 days post-sowing. Ribosomal DNA sequencing of the AMF-colonized thalli (mycothalli) revealed that they harboured phylogenetically diverse AMF; however, new gemmae sown around transplanted mycothalli showed evidence of colonization from phylogenetically uniform species. Of note, mycothalli can also be used as an inoculum. These results suggest that the young thalli of can potentially isolate monospecific AMF from field soil in a spore-independent manner.
丛枝菌根真菌（AMF）是一类与大多数陆地植物物种建立共生关系的土壤微生物。“根诱捕培养”通常用于分离单个再生孢子，以建立单特异性的本地AMF品系。根系可能会被多种AMF物种共同定殖；然而，根系内只有一小部分AMF会形成孢子，而且只有在特定条件下才会如此。在本研究中，我们测试了地钱的幼嫩叶状体（<2毫米）是否含有单特异性AMF，以及是否可以用作营养接种品系。当将芽孢与从田间获得的根系共同培养时，幼嫩叶状体在播种后18天通过假根被AMF感染并形成丛枝。对被AMF定殖的叶状体（菌根叶状体）进行核糖体DNA测序显示，它们含有系统发育多样的AMF；然而，在移植的菌根叶状体周围播种的新芽孢显示出被系统发育一致的物种定殖的迹象。值得注意的是，菌根叶状体也可以用作接种物。这些结果表明，地钱的幼嫩叶状体有可能以不依赖孢子的方式从田间土壤中分离出单特异性AMF。
