背景:与植物根系相关的外生菌根(ECM和ECM样)结构是科学家的挑战。根系在土壤剖面中的分散模式和营养条件都是促使植物进行ECM关联的有利因素。
结果:本研究讨论了菌根协会在Kobresia和Polygonum物种中的定植,Kobresiafilicina,K.Myosuroides,AlnusNitida,Betulapendula,樟子松,和在吉尔吉特-巴尔蒂斯坦(高海拔高山Deosai平原)的寒冷胁迫土壤中自然生长的三叶草,哈扎拉,斯瓦特,迪尔,还有Bajaur.将筛分的土壤批次暴露于+5°C(对照),-10,-20,-30,-40,-50,-125°C持续5小时,并在有利于ECM定殖的条件下将选定的植物播种到这些土壤中10周。在上述植物中检查了外生菌根关联。一些ECM真菌具有深色菌丝体,看起来像地幔和Hartig网。这些例子是Kobresiafilicina,K.Myosuroides,和轮胎花。这项研究的结果表明,K.myosuroides在ECM根尖长度方面表现出色,干质量,NH4浓度为-125℃。相反,A.Nitida展示了较低的值,表示其最小公差。值得注意的是,T.repens拥有最高的氮浓度(18.7±1.31mg/g),而P.sylvestris的磷含量为(3.2±0.22mg/g)。B.笔尖显示出最高的钾浓度(9.4±0.66mg/g),强调在极端寒冷条件下特定物种的养分吸收能力。PCA分析表明,参数,例如,土壤混合物中的NH4(NH4),土壤混合物中的NO3(NO3),种的土壤中的磷,Kobresiafilicina,K.Myosuroides,AlnusNitida,Betulapendula,樟子松,白三叶在+5°C的情况下最准确地表示,-10°C,和-20°C的温度。另一方面,ECM根尖(ECM)和干质量(DM)的参数最好描述为-40°C,-50°C,和-125°C的温度。所有参数对系统的可变性都有很大的影响,表明ECM的效率。热图支持与寄主植物的ECM定植呈正相关的养分。
结论:在较低温度下,根中的菌丝和孢子减少,而在冷胁迫土壤中,叶片的可溶性磷浓度增加。由于ECM的有效功能和定殖,在最低温度处理下在K.myosuroides中发现了最大的叶面养分浓度。
BACKGROUND: Ectomycorrhizal (ECM and ECM-like) structures associated with plant root systems are a challenge for scientists. The dispersion pattern of roots within the soil profile and the nutritional conditions are both favourable factors to motivate the plants to make ECM associations.
RESULTS: This study discusses the colonization of mycorrhizal associations in Kobresia and Polygonum species including Polygonum viviparum, Kobresia filicina, K. myosuroides, Alnus nitida, Betula pendula, Pinus sylvestris, and Trifolium repens grown naturally in cold stressed soils of Gilgit-Baltistan (high-altitude alpine Deosai plains), Hazara, Swat, Dir, and Bajaur. Sieved soil batches were exposed to +5 °C (control), -10, -20, -30, -40, -50, -125 °C for 5 h, and selected plants were sown to these soils for 10 weeks under favourable conditions for ECM colonization. Ectomycorrhizal associations were examined in the above mentioned plants. Some ECM fungi have dark mycelia that look like the mantle and Hartig net. Examples of these are Kobresia filicina, K. myosuroides, and Polygonum viviparum. Findings of this study revealed that K. myosuroides excelled in ECM root tip length, dry mass, and NH4 concentration at -125 °C. Contrarily, A. nitida demonstrated the lower values, indicated its minimum tolerance. Notably, T. repens boasted the highest nitrogen concentration (18.7 ± 1.31 mg/g), while P. sylvestris led in
phosphorus (3.2 ± 0.22 mg/g). The B. pendula showed the highest potassium concentration (9.4 ± 0.66 mg/g), emphasising species-specific nutrient uptake capabilities in extreme cold conditions. The PCA analysis revealed that the parameters, e.g., NH4 in soil mix (NH4), NO3 in soil mix (NO3),
phosphorus in soil in species of Polygonum viviparum, Kobresia filicina, K. myosuroides, Alnus nitida, Betula pendula, Pinus sylvestris, and Trifolium repens are most accurately represented in cases of + 5 °C, -10 °C, and -20 °C temperatures. On the other hand, the parameters for ECM root tips (ECM) and Dry Mass (DM) are best described in -40 °C, -50 °C, and - 125 °C temperatures. All parameters have a strong influence on the variability of the system indicated the efficiency of ECM. The heatmap supported the nutrients positively correlated with ECM colonization with the host plants.
CONCLUSIONS: At lower temperatures, hyphae and spores in roots were reduced, while soluble
phosphorus concentrations of leaves were increased in cold stress soils. Maximum foliar nutrient concentrations were found in K. myosuroides at the lowest temperature treatments due to efficient functioning and colonization of ECM.