Diversity of Arbuscular Mycorrhizal Fungi of the Rhizosphere of Lycium barbarum L. from Four Main Producing Areas in Northwest China and Their Effect on Plant Growth.

Arbuscular mycorrhizal fungi (AMF) can help plants absorb more mineral nutrients after they colonize plant roots, and the mycelia harmonize the soil structure and physical and chemical properties by secreting compounds. AMF species co-evolve with their habitat's geographic conditions and hosts; this gradually causes differences in the AMF species. By using Melzer's reagent to analyze the morphology and using Illumina Miseq sequencing technology to perform the molecular identification of AMF communities among the four typical L. barbarum planting areas (Zhongning, Guyuan, Jinghe, and Dulan) investigated, the variety of L. barbarum roots and rhizosphere AMF communities was greater in the Zhongning area, and every region additionally had endemic species. The successfully amplified AMF was re-applied to the L. barbarum seedlings. We found that the total dry weight and accumulation of potassium increased significantly (p < 0.05), and the root volume and number of root branches were significantly higher in the plants that were inoculated with Paraglomus VTX00375 in the pot experiment, indicating that AMF improves root development and promotes plant growth. We have investigated AMF germplasm species in four regions, and we are committed to the development of native AMF resources. The multiplication and application of AMF will be conducive to realizing the potential role of biology in the maintenance of agroecology.

Effects of temporal and spatial scales on soil yeast communities in the peach orchard.

Shihezi Reclamation Area is located at the southern edge of the Junggar Basin, with natural, soil, and climatic conditions unique to the production of peaches. In turn, peach orchards have accumulated rich microbial resources. As an important taxon of soil fungi, the diversity and community structure changes of yeast in the soil of peach orchards on spatial and temporal scales are still unknown. Here, we aimed to investigate the changes in yeast diversity and community structure in non-rhizosphere and rhizosphere soils of peach trees of different ages in the peach orchard and the factors affecting them, as well as the changes in the yeast co-occurrence network in the peach orchard at spatial and temporal scales. High-through put sequencing results showed that a total of 114 yeast genera were detected in all soil samples, belonging to Ascomycota (60 genera) and Basidiomycota (54 genera). The most dominant genus, Cryptococcus, was present in greater than 10% abundance in each sample. Overall, the differences in yeast diversity between non-rhizosphere and rhizosphere soil of peach trees at 3, 8 and 15 years were not significant. Principal coordinate analysis (PCoA) showed that differences in yeast community structure were more pronounced at the temporal scale compared to the spatial scale. The results of soil physical and chemical analysis showed that the 15-year-old peach rhizosphere soil had the lowest pH, while the OM, TN, and TP contents increased significantly. Redundancy analysis showed that soil pH and CO were key factors contributing to changes in soil yeast community structure in the peach orchard at both spatial and temporal scales. The results of co-occurrence network analysis showed that the peach orchard soil yeast network showed synergistic effects as a whole, and the degree of interactions and connection tightness of the 15-year-old peach orchard soil yeast network were significantly higher than the 3- and 8-year-old ones on the time scale. The results reveal the distribution pattern and mechanism of action of yeast communities in peach orchard soils, which can help to develop effective soil management strategies and improve the stability of soil microecology, thus promoting crop growth.

Analysis of microbial diversity and community structure of rhizosphere soil of Cistanche salsa from different host plants.

Host plants influence rhizosphere microorganism composition through root secretions, and rhizosphere associated microorganisms influence Cistanche seeds germination. At present, little is known about effects of different host plants on soil bacteria and fungi in the rhizosphere of Cistanche salsa. High-throughput sequencing was used here to reveal the similarities and differences in the structural composition of the soil microbial community of C. salsa from six host plants (i.e., Halocnemum strobilaceum, Atriplex patens, Kalidium foliatum, Caroxylon passerinum, Anabasis aphylla, Krascheninnikovia ceratoides). We discovered that Krascheninnikovia ceratoides-parasitizing C. salsa (YRCR6) had the highest diversity of rhizosphere bacterial communities, and Anabasis aphylla -parasitizing C. salsa (YRCR5) had the highest diversity of rhizosphere fungal communities. Fungal communities were more influenced by the host plant than bacterial communities. In addition, we discovered certain rhizosphere microorganisms that may be associated with Cistanche seeds germination, including Mortierella, Aspergillus alliaceus, and Cladosporium, which are account for a relatively high proportion in Halocnemum strobilaceum, Atriplex patens and Anabasis aphylla -parasitizing C. salsa. Redundancy analysis results also revealed that AP, HCO3 -, pH, Ca2+, SO4 2-, and K+ had a highly significant impact on the bacterial community structure (P < 0.01), while pH and SO4 2- had a significant impact on the fungal community structure (P < 0.05). Conclusively, differences were noted in the structure of rhizosphere bacterial and fungal communities of C. salsa parasitizing different plants in the same habit and the difference may be related to the host plant. This result can provide a new ideas for the selection of host plants and the cultivation of C. salsa.

Predicting Distribution of the Asian Longhorned Beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae) and Its Natural Enemies in China.

The Asian longhorned beetle, Anoplophora glabripennis, is a forestry pest found worldwide. A. glabripennis causes serious harm because of the lack of natural enemies in the invaded areas. Dastarcus helophoroides and Dendrocopos major are important natural enemies of A. glabripennis. MaxEnt was used to simulate the distribution of D. helophoroides and D. major in China, and their suitable areas were superimposed to pinpoint which regions are potentially appropriate to release or establish natural enemy populations under current and future conditions. The results showed that, with climate change, the suitable areas of D. helophoroides and D. major migrated northward; the centroid shift of A. glabripennis was greater than those of D. helophoroides and D. major. From current conditions to 2090, the suitable area of A. glabripennis, D. helophoroides, and D. major will increase by 1.44 × 104, 20.10 × 104, and 31.64 × 104 km2, respectively. Northern China (e.g., Xinjiang, Gansu, and Inner Mongolia), where A. glabripennis causes more serious damage, is also a potentially suitable area for D. helophoroides and D. major, and this provides a potential strategy for the management of A. glabripennis. Therefore, we suggest that natural enemies should be included in the model used for predicting suitable areas for invasive pests.

Soil Microbes Drive the Flourishing Growth of Plants From Leucocalocybe mongolica Fairy Ring.

Fairy ring is a natural phenomenon in which fungal fruiting bodies occur as a ring on a spot. This ring is produced due to spore ejection by Basidiomycetous fungi and forms a lush growing plant belt. However, the drivers for such formations and the potential plant growth-promoting rhizobacteria in fairy ring soils remain unknown. Fairy rings formed by Leucocalocybe mongolica were selected in this study. Soil characteristics and microbial (bacteria and fungi) community structures between beneath and outside the fairy rings were compared through high-throughput sequencing. Beneficial bacterial resources were excavated using dependent culturable methods. Soil electrical conductivity and available potassium were higher in the soil beneath the ring than outside it. These parameters were positively correlated with the dominant microbial community, but microbial diversity was lower. In the soil beneath the fairy ring, Bacteroidetes and Basidiomycota were more abundant, whereas Verrucomicrobia was less prevalent. Bacillus pumilus (strain BG-5) was isolated from the soil beneath the ring. Strain BG-5 can solubilize phosphorus and produce indole-3-acetic acid, NH4 +, and siderophores. Furthermore, strain BG-5 enhanced salt tolerance and promoted the growth of Arabidopsis thaliana, wheat (Triticum aestivum), and cotton (Gossypium hirsutum) seedlings. This study indicated the presence of abundant beneficial microbes driving the flourishing growth of plants in the fairy ring soil and provided bio-resources for agricultural growth-promoting agents.

Illumina MiSeq Sequencing Reveals Correlations among Fruit Ingredients, Environmental Factors, and AMF Communities in Three Lycium Barbarum Producing Regions of China.

The symbiotic relationship of arbuscular mycorrhizal fungi (AMF) is important for Lycium barbarum, a highly nutritious and medicinal crop. However, the influence of environmental factors on AMF communities remains largely elusive. Based on MiSeq sequencing, we analyzed AMF communities in rhizosphere soils of L. barbarum with growth synchronization in three typical L. barbarum cultivation sites in China. The Zhongning region has poor soils with a high richness of AMF communities. Geographical environmental variances lead to differences in AMF communities which in turn affects the active ingredients of L. barbarum fruit. Furthermore, different genera of AMF showed significant correlations with environmental factors and fruit ingredients. The three genera, Claroideoglomus, Dominikia, and Funneliformis correlated to environmental factors and fruits ingredients in a similar manner affecting the whole sugar (TS) and flavonoids (FLA) contents in the fruits of L. barbarum. Also, these showed a significantly positive correlation with soil pH. This fact was unknown so far due to different soil acidity/alkalinity in different studies. IMPORTANCE The climatic and ecological environment is a complex phenomenon, involving various environmental factors that regulate the diversity and population distribution structure of AMF communities affecting plant growth, crop composition, and yield. Current studies on the effects of environmental factors on AMF communities have mainly focused on soil conditions and host plants. Fewer studies have been conducted on the correlation between temperature, enzyme activity, plant fruiting, and AMF communities. The present study investigated the diversity of AMF communities and the influence of environmental factors on their distribution patterns, which showed similar effects on some AMF species. The results suggest that screening AMF fungicides that meet the target may significantly help soil restoration reducing the use of chemical fertilizers and a large amount of human and material resources.

Patterns of yeast diversity distribution and its drivers in rhizosphere soil of Hami melon orchards in different regions of Xinjiang.

BACKGROUND: The unique climatic conditions of the Xinjiang region nurture rich melon and fruit resources, the melon and fruit sugar sources provide sufficient nutrients for the survival of yeast, and the diverse habitats accompanied by extreme climatic conditions promote the production of yeast diversity and strain resources. However, the relationship between yeast species and their relationship with environmental factors in the soil of Xinjiang specialty cash crop Hami melon is not clear. Here, we aimed to characterize the diversity, community structure, and relationship between yeast species and environmental factors in Hami melon orchards soils in different regions of Xinjiang, China. RESULTS: Based on Illumina MiSeq high-throughput sequencing analysis of the D1 domain of the LSU rRNA genes, the community richness of yeast in the soil of Northern Xinjiang was higher than in the Southern and Eastern Xinjiang, but the community diversity was significantly lower in the Northern Xinjiang than in the Southern and Eastern Xinjiang. A total of 86 OTUs were classified into 59 genera and 86 species. Most OTUs (90.4%) belonged to the Basidiomycota; only a few (9.6%) belonged to Ascomycota. The most dominant species in the Southern, Eastern and Northern Xinjiang were Filobasidium magnum (17.90%), Solicoccozyma aeria (35.83%) and Filobasidium magnum (75.36%), respectively. Principal coordinates analysis (PCoA) showed that the yeast community composition in the soils of the three regions were obviously different, with the Southern and Eastern Xinjiang having more similar yeast community. Redundancy analysis (RDA) showed that soil factors such as conductivity (CO), total phosphorus (TP) and Total potassium (TK) and climate factors such as average annual precipitation (PRCP), relative humidity (RH) and net solar radiation intensity (SWGNT) were significantly correlated with yeast communities (P < 0.05). CONCLUSION: There are abundant yeast resources in the rhizosphere soil of Hami melon orchard in Xinjiang, and there are obvious differences in the diversity and community structure of yeast in the three regions of Xinjiang. Differences in climatic factors related to precipitation, humidity and solar radiation intensity and soil factors related to conductivity, total phosphorus and total potassium are key factors driving yeast diversity and community structure.

Diurnal cycle and seasonal variation of cloud cover over the Tibetan Plateau as determined from Himawari-8 new-generation geostationary satellite data.

Analysis of cloud cover and its diurnal variation over the Tibetan Plateau (TP) is highly reliant on satellite data; however, the accuracy of cloud detection from both polar-orbiting and geostationary satellites over this area remains unclear. The new-generation geostationary Himawari-8 satellites provide high-resolution spatial and temporal information about clouds over the Tibetan Plateau. In this study, the cloud detection of MODIS and AHI is investigated and validated against CALIPSO measurements. For AHI and MODIS, the false alarm rate of AHI and MODIS in cloud identification over the TP was 7.51% and 1.94%, respectively, and the cloud hit rate was 73.55% and 80.15%, respectively. Using hourly cloud-cover data from the Himawari-8 satellites, we found that at the monthly scale, the diurnal cycle in cloud cover over the TP tends to increase throughout the day, with the minimum and maximum cloud fractions occurring at 10:00 a.m. and 18:00 p.m. local time. Due to the limited time resolution of polar-orbiting satellites, the underestimation of MODIS daytime average cloud cover is approximately 4.00% at the annual scale, with larger biases during the spring (5.40%) and winter (5.90%).