Impact of Phosphorus Fertilization on Tomato Growth and Arbuscular Mycorrhizal Fungal Communities

Cleary

et al. 2020

Forests

Background and Objectives: Arbuscular mycorrhizal fungi (AMF) play a crucial role in individual plant capability and whole ecosystem sustainability. Chinese fir, one of the most widely planted tree species in southern China, forms associations with AMF. However, it is still unclear what impacts thinning management applied to Chinese fir plantations has on the structure and diversity of soil AMF communities. This research attempts to bridge this knowledge gap. Materials and Methods: A thinning experiment was designed on different slope positions in Chinese fir plantations to examine the impacts of slope position and thinning intensity on colonization, diversity, and community composition of AMF. Results: Our research showed that the altitudinal slope position had significant effects on colonization, diversity, and community composition of AMF in Chinese fir plantations. In addition, the interaction between slope position and thinning intensity had significant effects on AMF diversity. Colonization by AMF on the lower slope position was significantly higher than on the upper slope position, while AMF diversity on the upper slope position was higher than on the middle and lower slope positions. Glomus was the most abundant genus in all slope positions, especially on the middle and lower slope positions. The relative abundance of Diversispora was significantly different among slope positions with absolute dominance on the upper slope position. Scutellospora was uniquely found on the upper slope position. Furthermore, soil Mg and Mn contents and soil temperature positively affected AMF community composition at the operational taxonomic unit (OTU) level. Conclusions: These findings suggested that slope position should be considered in the management of Chinese fir plantations. Furthermore, both chemical fertilization and AMF augmentation should be undertaken on upper hill slope positions as part of sustainable management practices for Chinese fir plantations.Forests 2020, 11, 273 2 of 20 both timber production and ecosystem maintenance. In such production forests, growth has not been satisfactorily uniform, although the area of the plantations has increased substantially in recent decades [3,4]. This is because most plantations were initially planted at high density and have not been efficiently managed with thinning [1,5,6]. In addition, these plantations may exhibit other problems associated with monocultures [3,7], such as simple community structure, lack of biological stability, litter decomposition tardiness, and soil nutrient and land fertility losses [4,8,9], which seriously affect the long-term productivity and sustainable management of the plantations [8,10,11].Thinning, as an important silvicultural practice, affects forest characteristics directly and indirectly, such as overstory, understory, soil properties [1,12,13], and microbial communities [14,15]. Several studies have shown that the development of understory after thinning results in an increasing proportion of rapidly decomposable litter, which could...

Section: Discussionsupporting

confidence: 94%

Section: Discussionsupporting

confidence: 94%

Slope Position Rather Than Thinning Intensity Affects Arbuscular Mycorrhizal Fungi (AMF) Community in Chinese Fir Plantations

Cleary

et al. 2020

Forests

“…It has been shown that the function whereby AMF species provide phosphorus to their host plants is phylogenetically conserved [ 47 ], such that different AMF phylogenetic groups would exhibit significant differences in availability. For example, the diversity of AMF communities associated with soybean roots was significantly influenced by P application [ 48 ], whereas such application did not affect AMF root colonization or the diversity/structure of AMF communities associated with tomato plants [ 49 ]. As such, it is possible that low P availability may select for functionally similar AMF species exhibiting highly efficient P uptake.…”

Section: Discussionmentioning

confidence: 99%

High-throughput sequencing analysis of the rhizosphere arbuscular mycorrhizal fungi (AMF) community composition associated with Ferula sinkiangensis

Luo

et al. 2020

BMC Microbiol

Background Ferula sinkiangensis is an increasingly endangered medicinal plant. Arbuscular mycorrhiza fungi (AMF) are symbiotic microorganisms that live in the soil wherein they enhance nutrient uptake, stress resistance, and pathogen defense in host plants. While such AMF have the potential to contribute to the cultivation of Ferula sinkiangensis, the composition of AMF communities associated with Ferula sinkiangensis and the relationship between these fungi and other pertinent abiotic factors still remains to be clarified. Results Herein, we collected rhizosphere and surrounding soil samples at a range of depths (0–20, 20–40, and 40–60 cm) and a range of slope positions (bottom, middle, top). These samples were then subjected to analyses of soil physicochemical properties and high-throughput sequencing (Illumina MiSeq). We determined that Glomus and Diversispora species were highly enriched in all samples. We further found that AMF diversity and richness varied significantly as a function of slope position, with this variation primarily being tied to differences in relative Glomus and Diversispora abundance. In contrast, no significant relationship was observed between soil depth and overall AMF composition, although some AMF species were found to be sensitive to soil depth. Many factors significantly affected AMF community composition, including organic matter content, total nitrogen, total potassium, ammonium nitrogen, nitrate nitrogen, available potassium, total dissolvable salt levels, pH, soil water content, and slope position. We further determined that Shannon diversity index values in these communities were positively correlated with total phosphorus, nitrate-nitrogen levels, and pH values (P < 0.05), whereas total phosphorus, total dissolvable salt levels, and pH were positively correlated with Chao1 values (P < 0.05). Conclusion In summary, our data revealed that Glomus and Diversispora are key AMF genera found within Ferula sinkiangensis rhizosphere soil. These fungi are closely associated with specific environmental and soil physicochemical properties, and these soil sample properties also differed significantly as a function of slope position (P < 0.05). Together, our results provide new insights regarding the relationship between AMF species and Ferula sinkiangensis, offering a theoretical basis for further studies of their development.

“…It has been shown that the function whereby AMF species provide phosphorus to their host plants is phylogenetically conserved [47], such that different AMF phylogenetic groups would exhibit signi cant differences in availability. For example, the diversity of AMF communities associated with soybean roots was signi cantly in uenced by P application [48], whereas such application did not affect AMF root colonization or the diversity/structure of AMF communities associated with tomato plants [49]. As such, it is possible that low P availability may select for functionally similar AMF species exhibiting highly e cient P uptake.…”

Section: Discussionmentioning

confidence: 99%

High-throughput sequencing analysis of the rhizosphere arbuscular mycorrhizal fungi (AMF) community composition associated with Ferula sinkiangensis

Luo

et al. 2020

Preprint

Background: Ferula sinkiangensis is an increasingly endangered medicinal plant. Arbuscular mycorrhiza fungi (AMF) are symbiotic microorganisms that live in the soil wherein they enhance nutrient uptake, stress resistance, and pathogen defense in host plants. While such AMF have the potential to contribute to the cultivation of Ferula sinkiangensis, the composition of AMF communities associated with Ferula sinkiangensis and the relationship between these fungi and other pertinent abiotic factors still remains to be clarified.Results: Herein, we collected rhizosphere and surrounding soil samples at a range of depths (0-20, 20-40, and 40-60 cm) and a range of slope positions (bottom, middle, top). These samples were then subjected to analyses of soil physicochemical properties and high-throughput sequencing (Illumina MiSeq). We determined that Glomus and Diversispora species were highly enriched in all samples. We further found that AMF diversity and richness varied significantly as a function of slope position, with this variation primarily being tied to differences in relative Glomus and Diversispora abundance. In contrast, no significant relationship was observed between soil depth and overall AMF composition, although some AMF species were found to be sensitive to soil depth. Many factors significantly affected AMF community composition, including organic matter content, total nitrogen, total potassium, ammonium nitrogen, nitrate nitrogen, available potassium, total dissolvable salt levels, pH, soil water content, and slope position. We further determined that Shannon diversity index values in these communities were positively correlated with total phosphorus, nitrate-nitrogen levels, and pH values (P<0.05), whereas total phosphorus, total dissolvable salt levels, and pH were positively correlated with Chao1 values (P<0.05). Conclusion: In summary, our data revealed that Glomus and Diversispora are key AMF genera found within Ferula sinkiangensis rhizosphere soil. These fungi are closely associated with specific environmental and soil physicochemical properties, and these soil sample properties also differed significantly as a function of slope position (P<0.05). Together, our results provide new insights regarding the relationship between AMF species and Ferula sinkiangensis, offering a theoretical basis for further studies of their development.