Institute of Botany, The Czech Academy of Sciences, 242 43, Průhonice, Czech Republic.
Biology Centre, Institute of Hydrobiology, The Czech Academy of Sciences, 370 05, České Budějovice, Czech Republic.
Mycorrhiza. 2021 May;31(3):273-288. doi: 10.1007/s00572-020-01017-y. Epub 2021 Jan 24.
Arbuscular mycorrhizal fungi (AMF) colonize the roots of numerous aquatic and wetland plants, but the establishment and functioning of mycorrhizal symbiosis in submerged habitats have received only little attention. Three pot experiments were conducted to study the interaction of isoetid plants with native AMF. In the first experiment, arbuscular mycorrhizal (AM) symbiosis did not establish in roots of Isoëtes echinospora and I. lacustris, while Littorella uniflora roots were highly colonized. Shoot and root biomass of L. uniflora were, however, not affected by AMF inoculation, and only one of nine AMF isolates significantly increased shoot P concentration. In the second experiment, we compared colonization by three Glomus tetrastratosum isolates of different cultivation history and origin (aquatic versus terrestrial) and their effects on L. uniflora growth and phosphorus nutrition under submerged versus terrestrial conditions. The submerged cultivation considerably slowed, but did not inhibit mycorrhizal root colonization, regardless of isolate identity. Inoculation with any AMF isolate improved plant growth and P uptake under terrestrial, but not submerged conditions. In the final experiment, we compared the communities of AMF established in two cultivation regimes of trap cultures with lake sediments, either submerged on L. uniflora or terrestrial on Zea mays. After 2-year cultivation, we did not detect a significant effect of cultivation regime on AMF community composition. In summary, although submerged conditions do not preclude the development of functional AM symbiosis, the contribution of these symbiotic fungi to the fitness of their hosts seems to be considerably less than under terrestrial conditions.
丛枝菌根真菌（AMF）会定殖在许多水生和湿地植物的根部，但在淹没生境中建立和发挥菌根共生作用的问题却很少受到关注。进行了三项盆栽实验来研究内生植物与本地 AMF 的相互作用。在第一个实验中，丛枝菌根（AM）共生没有在 Isoëtes echinospora 和 I. lacustris 的根部建立，而 Littorella uniflora 的根部则被高度定殖。然而，L. uniflora 的地上部和地下部生物量不受 AMF 接种的影响，只有九个 AMF 分离株中的一个显著增加了地上部 P 浓度。在第二个实验中，我们比较了三种不同栽培历史和起源（水生和陆生）的 Glomus tetrastratosum 分离株的定殖情况及其对 L. uniflora 在淹没和陆生条件下生长和磷营养的影响。无论分离株的身份如何，淹没培养都会显著减缓但不会抑制菌根根的定殖。接种任何 AMF 分离株都能提高植物在陆生条件下的生长和 P 吸收，但在淹没条件下则不能。在最后的实验中，我们比较了在两种培养条件下建立的丛枝菌根真菌群落，一种是在水生的 L. uniflora 上进行的陷阱培养，另一种是在陆生的 Zea mays 上进行的陷阱培养。经过 2 年的培养，我们没有检测到培养条件对 AMF 群落组成的显著影响。总的来说，尽管淹没条件不会阻止功能性 AM 共生的发展，但这些共生真菌对其宿主适应性的贡献似乎明显小于陆生条件下的贡献。
