Effects of Altitude and Continuous Cropping on Arbuscular Mycorrhizal Fungi Community in Siraitia grosvenorii Rhizosphere

Abstract

Siraitia grosvenorii, a medicinal plant with continuous cropping, is cultivated in southern China. Changes in the soil microbial community during continuous cropping can cause soil-borne diseases in S. grosvenorii. This experimental study aimed to determine the differences in the arbuscular mycorrhizal fungi (AMF) community structure and root colonization in the rhizosphere soil of S. grosvenorii with different continuous cropping years and altitudes. We tested three altitude gradients (low, 200–300 m; middle, 500–600 m; and high, 700–800 m) and four continuous cropping years (1, 2, 3, and 5 years). AMF colonization, along with AMF spore density, and the soil physicochemical properties of S. grosvenorii roots at different altitudes and continuous cropping years were determined. Illumina high-throughput sequencing was used to determine the molecular diversity of AMF in the rhizosphere of S. grosvenorii as they exhibited a symbiotic relationship. The AMF species in the rhizosphere soil of S. grosvenorii included 28 species of nine genera, including Glomus, Claroideoglomus, Acaulospora, Paraglomus, Ambispora, and so on. With an increasing altitude, the AMF colonization of S. grosvenorii roots increased significantly (p < 0.01); available phosphorus (AP) content was negatively correlated with AMF colonization (p < 0.01). Glomus and Paraglomus were the common dominant genera in the rhizosphere soil of S. grosvenorii planted for 2–5 years at a low altitude and 1 year at middle and high altitudes. The average relative abundance of Glomus increased with increasing continuous cropping years and altitude in the low-altitude and 1-year S. grosvenorii areas, respectively. Slightly acidic rhizosphere soil contributed to AMF colonization and improved the richness and diversity of the AMF community. Our results showed that altitude, AP, and pH are essential factors for predicting AMF infection and community changes in the S. grosvenorii rhizosphere. Here, Illumina high-throughput sequencing was used to study the species resources and community composition of mycorrhizal fungi in S. grosvenorii in the hilly areas of Guangxi, China. This study provides a theoretical basis for the application and practice of mycorrhizal fungi including the isolation and screening of dominant strains, inoculation of mycorrhizal fungi, and exploration of the effects of mycorrhizal fungi on the growth and active ingredients of medicinal plants.

Arbuscular Mycorrhizal Fungi Diversity in Sophora japonica Rhizosphere at Different Altitudes and Lithologies

“…These advantages may be attributed to the positive feedback loop between AMF and acidic soil stress. This understanding aligns with the results of a study that evaluated the pH of Siraitia grosvenorii in Guangxi; in this study, an increase in AMF richness and diversity was observed with increasing pH [25]. Therefore, exploring the sensitivity of mycorrhizal fungi to soil pH and evaluating how soil pH drives microbial niche differentiation in rocky desertification areas could offer innovative approaches to harness biodiversity for the mitigation of rocky desertification and facilitation of ecological restoration.…”

“…This study revealed the AMF germplasm resources in the rhizosphere of S. japonica, and 22 species were identified by Glomus. Glomus has also been identified as a predominant genus in the rhizosphere of other medicinal plants, including Rosa laevigata Michx [24] and Siraitia grosvenorii [25]. These results may, ultimately, be attributed to the adaptive characteristics of Glomus.…”

“…The broad ecological adaptability of Glomus spp. influences their ability to survive under stressful environments, such as tropical rainforests, deserts, and karst rocky desertification regions [25]. Therefore, exploring the relationship between altitude and the reproduction and dispersal ability of functional species will provide a basis for the preservation and application of mycorrhizal fungal germplasm resources.…”

“…[26,31,42]. Moreover, Glomus is a well-known genus with a high growth rate and strong adaptability [25]. Further, Claroideoglomus, with its wide niche distribution in various areas, such as forestland, grassland, and shrubland, can gain an advantage in the early and mid-successional stages [43].…”

Soil Bacterial Community Structure and Physicochemical Influencing Factors of Artificial Haloxylon ammodendron Forest in the Sand Blocking and Fixing Belt of Minqin, China

“…The RawReads data at both ends were subjected to individual quality clipping using the Fastp software (version 0.14.4), while the primers at both ends were eliminated through the employment of the Cutadapt software (version 1.14), thereby yielding valid sequences [39]. Subsequently, the Usearch software's Uparse (version 10.0.240) algorithm was employed to cluster the sample quality sequences into OTUs, and the Silva 16S database was utilized to annotate the species, thereby obtaining taxonomic information for the OTUs.…”