Data_Sheet_1_Effect of natural weed and Siratro cover crop on soil fungal diversity in a banana cropping system in southwestern China.docx

IntroductionNatural weed cover and a legume cover crop were examined to determine if they could impact soil fungal diversity as an indicator of soil quality in banana production.
MethodsBanana in Yunnan Province, China, was grown under three treatments: conventional tillage (bare soil), natural weed cover (primarily goosegrass (Eleusine indica (L.) Gaerth)), or a cover crop (Siratro (Macroptilium atropurpureum (DC.) Urb.)). Analysis of the soil fungal communities between 2017 and 2020 was done by Illumina Miseq high-throughput sequencing.
ResultsMost significant effects were in the intercropping area for the treatments, whereas it was rarely observed in the furrow planted with banana. Based on the Shannon and Simpson diversity indices, soil fungal diversity in the intercropping area significantly decreased following planting banana in 2017 with all three treatments. However, both the Shannon and Simpson diversity indices showed that there were significant increases in fungal soil diversity in 2019 and 2020 with natural weed cover or Siratro compared to bare soil. At the end of the experiment, significant increases in fungal genera with Siratro compared to bare soil were observed with Mortierella, Acremonium, Plectophaerella, Metarhizium and Acrocalymma, and significant decreases were observed with Fusicolla, Myrothecium, Exserohilum, Micropsalliota and Nigrospora. Siratro resulted in higher stability of the soil fungal microbiome by increasing the modularity and the proportion of negative co-occurrences compared to bare soil. For fungal guilds, Siratro significantly increased saprotrophs_symbiotrophs in 2019 and 2020 and significantly decreased pathogens_saprotrophs in 2020 compared to bare soil.
DiscussionUsing Siratro as a cover crop in the intercropping area of banana helped maintain soil fungal diversity, which would be beneficial for soil health with more symbiotrophs and less pathogens in the soil. However, further research is needed to determine the long-term impact of weed or Siratro cover crop on the fungal soil ecosystem and growth of banana.

引言：本研究以土壤真菌多样性作为土壤质量的评价指标，探究自然覆草与豆科覆盖作物对香蕉种植体系中土壤真菌多样性的影响。
方法：本研究在中国云南省开展香蕉种植试验，设置三种处理方式：常规耕作（裸土）、自然覆草（主要为牛筋草（Eleusine indica (L.) Gaerth））以及覆盖作物——大翼豆（Siratro, Macroptilium atropurpureum (DC.) Urb.）。于2017年至2020年间采用Illumina Miseq高通量测序技术对土壤真菌群落进行分析。
结果：三种处理的显著效应主要集中于间作区域，而在香蕉种植的垄沟中极少观测到此类效应。基于香农（Shannon）与辛普森（Simpson）多样性指数，2017年三种处理下的间作区域土壤真菌多样性均在种植香蕉后显著下降。然而，香农与辛普森多样性指数均显示，2019年和2020年，自然覆草或大翼豆处理的土壤真菌多样性较裸土处理显著提升。试验结束时，相较于裸土处理，大翼豆处理的土壤真菌类群中，被孢霉属（Mortierella）、顶孢霉属（Acremonium）、格孢腔菌属（Plectosphaerella）、绿僵菌属（Metarhizium）以及暗球壳属（Acrocalymma）的相对丰度显著升高，而腐皮壳属（Fusicolla）、漆斑霉属（Myrothecium）、突脐蠕孢属（Exserohilum）、小皮伞属（Micropsalliota）以及黑孢霉属（Nigrospora）的相对丰度显著降低。大翼豆处理较裸土处理提升了真菌群落的模块化程度与负共现比例，从而提高了土壤真菌微生物组的稳定性。对于真菌功能群而言，相较于裸土处理，大翼豆处理在2019年和2020年显著提升了腐生-共生营养型（saprotrophs_symbiotrophs）的相对丰度，并在2020年显著降低了病原-腐生营养型（pathogens_saprotrophs）的相对丰度。
讨论：在香蕉间作区域种植大翼豆作为覆盖作物，有助于维持土壤真菌多样性，通过提升土壤中共生营养型真菌的占比、降低病原真菌的占比，进而改善土壤健康状况。然而，仍需开展进一步研究以明确自然覆草或大翼豆覆盖作物对土壤真菌生态系统以及香蕉生长的长期影响。