Study On Soil Microbial Diversity Under Different Wheat Tillage Patterns

As one of the traditional grains in China,wheat is of great importance in food security in China.Anhui Province is a major wheat producing province,with a wide cultivation area.Due to the widespread cultivation of wheat,wheat diseases caused by multiple pathogenic infestations are a serious threat to food security production.Currently,some antagonistic bacteria in the soil microbial community are able to act antagonistically against wheat disease pathogens and thus control the disease occurrence.In agricultural production,tillage patterns(crop rotation,straw return)and the selection of disease-resistant wheat cultivars have an impact on improving soil microbial diversity and community structure.However,there are few reports on the effects of wheat tillage patterns and different cultivars on soil microbial community in Anhui Province.The aim of this study was to investigate the effects of different tillage patterns(crop rotation,straw returning)and wheat cultivars on soil bacterial and fungal communities.Firstly,high-throughput sequencing technology was used to identify the soil microbial community of different straw returning treatments under wheatmaize rotation pattern;then the composition and functions of soil bacterial and fungal communities of different wheat cultivars under rice-wheat rotation pattern were analyzed.The main results are as follows:(1)Effects of different straw returns on soil microbial communitiesThe results showed that wheat and maize straw returning(FB)reduced bacterial diversity but had no effect on fungal diversity during the wheat season,compared with no straw return(FCK).During the maize season,returning wheat and maize stalks to the field increased the diversity of bacteria,whereas returning maize stalks to the field(SM)reduced the diversity of fungi,compared with no straw return(SCK).In addition,we detected a fungal pathogen(Fusarium)under the two planting patterns and found that the relative abundance of pathogenic Fusarium increased with wheat straw return.At the same time,we detected some beneficial genera(Bradyrhizobium,Chaetomium,Trichoderma).In addition,there were also other different groups of microorganisms(bacteria and fungi)that were enriched in all treatments,and identified at the class,order,family and genus levels.The symbiotic network analysis showed that bacterial networks are more complex than fungal networks.(2)Effect of different wheat cultivars on soil microbial communitiesIn this study,we choosed four wheat cultivars that were resistant or susceptible to wheat scab.The results showed that wheat moderately susceptible cultivars increase soil microbial diversity(bacteria and fungi).The PCoA results indicated that the differences in soil microbial communities are caused by differences in resistance and susceptibility of wheat cultivars.Furthermore,we detected three beneficial genera(Rhodanobacter,Sphingomonas,Pseudomonas)and one pathogenic fungal genus(Fusarium).Fusarium is a genus of pathogenic fungi that causes wheat scab,which relative abundance was the highest in wheat highly resistant cultivars and the lowest in wheat highly susceptible cultivars.It is indicated that the selection of wheat cultivars with high resistance is of great significance to control wheat scab and promote the development of green agriculture.Functional analysis showed that different resistant wheat cultivars had significant differences in function.In summary,this study clarified the effects of wheat tillage patterns and different crop cultivars on soil microbial diversity and community structure,aiming to provide a scientific basis for straw returning to the field and rational distribution of wheat cultivars in agricultural production.