Seasonal patterns of fungal colonisation in Australian native plants of different ages

Plant fungal relationships should vary with abiotic and biotic factors to minimise plant stress and are likely to vary seasonally and with age. We investigated how fungal colonisation, specifically arbuscular mycorrhizal fungi and dark septate fungal endophytes, would vary with species identity and season, and how these interactions change with ontogeny. Plant roots of adults and seedlings of 9 species were collected from heathland and coastal dune habitats along the Australian east coast in New South Wales. Roots were stained and investigated for arbuscular mycorrhizal fungi and dark septate endophyte structures to determine colonisation strength. Species identity was the most important factor driving colonisation strength, while low rainfall and heatwaves were associated with declining arbuscular mycorrhizal fungi colonisation in the warmest sampling period. AMF colonisation may be supressed by plants under heat and water stress as a way of avoiding loss of limited photosynthates. Dar...植物与真菌的关联会随非生物因子与生物因子发生变化，以降低植物所受的胁迫，且这类关联大概率会随季节与植株年龄产生差异。本研究探究了真菌定殖——尤其是丛枝菌根真菌（arbuscular mycorrhizal fungi, AMF）与深色有隔内生真菌（dark septate fungal endophytes, DSE）——如何随物种种类与季节发生变化，同时也分析了这些互作关系如何随个体发育（ontogeny）发生改变。我们从澳大利亚东海岸新南威尔士州的石楠荒原与沿海沙丘生境中，采集了9个物种的成年植株与幼苗的根系样本。对根系进行染色处理后，观测丛枝菌根真菌与深色有隔内生真菌的结构特征，以此确定真菌定殖强度。物种种类是驱动定殖强度的最关键因子，而在最热的采样时段，低降雨量与热浪事件与丛枝菌根真菌定殖率的下降存在关联。处于热胁迫与水分胁迫下的植物或可抑制丛枝菌根真菌的定殖，以此避免有限光合产物的流失。Dar...