Dynamic Analysis Of Soil Microbial Population About Straw Addition Combined Flooding On High-incidence Banana Orchard

Restoring the cultivation of banana plantations with high incidence of blight is the key to the sustainable development of the banana industry.Our previous studies have shown that the combined flooding treatment of straw can significantly reduce the abundance and quantity of banana blight pathogens in the soil of banana gardens with high incidence of blight.Improve the physical and chemical properties of the soil and microbial community structure,and quickly restore the banana plantation.On the basis of the above research,this project used traditional separation culture combined with high-throughput sequencing technology to analyze the microbial population dynamics in the process of straw combined flooding treatment of high-blight wilt disease banana garden soil,and preliminary exploration of straw combined flooding treatment to construct healthy bananas The microbiological mechanism of the garden soil as follows:Compared with continuous cropping bananas(controlling experiment),the combined flooding and straw addition flooded soil Eh decreased rapidly in the first 30 days.With the extension of time,the soil Eh changed slowly,and the soil p H increased quickly in the first 30 days,and later The soil p H changes little;under the influence of the strong reducing environment of the soil and soil microorganisms,the nitrate nitrogen content in the soil gradually decreases with time,and the ammonium nitrogen content gradually increases;when the water is flooded to day 60,the soil The number of bacteria and fungi is the lowest,and the difference is not obvious in the later period.The number and copy number of Fusarium oxysporum that can be cultured at 90 days are the lowest.The copy number of fluorescent quantitative PCR decreased by 0.66 log units,and the difference is not significant in the later period;298 strains of bacteria and 376 strains of fungi were isolated from the field soil of the high-risk banana orchard.The identification showed that the soil had microbial community characteristics dominated by Bacillus(25.90%)and Aspergillus(30.17%).With the change of the potting soil flooding time(30,60,90,120 days),in terms of species diversity,the original microbial community characteristics were broken after 30 days of flooding,forming the genus Stenotrophomonas(23.48%)and Trichoderma(26.99%)-based microbial community structure;60 days after the bacterial community succession to Streptomyces(17.80%)-based bacterial colony distribution characteristics,fungal community structure types.After the test period,it will remain unchanged;the distribution of bacterial community structure types is stable within 90 to 120 days,forming colonies dominated by Exiguobacterium(19.67%),and the content of ammonium nitrogen may be one of the influencing factors.In the first 30 days,the cultivable microbial strains in the combined straw and flooded soils decreased the fastest,and the reduction in the later period slowed down.Among them,the number of fungal strains decreased significantly more than the number of bacterial strains;at the genus level,bacteria from 22 genera It was reduced to 12 genera,and the fungus decreased from 17 genera to 7 genera.The change of bacterial fungi decreased after 30 days;on day 60,the number of fungal strains was the smallest,and on day 90 the number of bacterial strains was the least.After 120 days of experiment,the high-throughput analysis results of soil microbial metagenomics indicated that the dominant microbial species common in flooded and non-submerged soils were: anaerobic chlamydia,anaerobic ammonia-oxidizing bacteria,anaerobic bacteria,bacillus,Ellin6067,Nitrospira,Haliangium,Bacillus,MND1,Subgroup-10,Monospora,RB41,Marseille,Streptomyces,Nocardia,It is a dominant bacterial genus;Salmonella,Psyllium,Humicola,Aspergillus,Fusarium,Acremonium,Penicillium,Chaetomium,Sporogenes,C orynecystis,Rhizobia.The genus Mycobacterium,Grape spp.,Myriophyllum,Arthrobacter and Discus are the dominant fungal genus.Among them,the relative abundance of anaerobic rope genus,anaerobic ammonium oxidizing bacteria and anaerobic bacteria was higher with the addition of straw and combined flooding in the continuous cropping banana plantation soil,with the largest increase,greater than1%;Genus,Anaerobic ammonia-oxidizing bacteria,anaerobic bacteria,Ellin6067 and Nitrospirillum have relatively high abundance,the largest increase,greater than 1%;fallow treatment of soil Streptomyces,Anaerobic ammonia-oxidizing bacteria,Bacillus,The relative abundance of Marseille,Nocardia and RB41 is relatively high,with the largest increase,greater than 1%.Among them,straw addition combined flooding treatment soil Anaerobic Aspergillus(dominant bacteria)accounted for more than the other three treatments,the sum of the relative abundance of beneficial microorganisms(such as Chaetomium,Arthrobacter)was higher than the other three treatments,The sum of the relative abundance of harmful microorganisms(such as Grape spp.and Fusarium spp.)is lower than that of the other three treatments.The 120-day treatment of combined straw flooding shows that the beneficial bacteria Streptomyces and the beneficial fungus Chaetomium in the soil are both of the classic culturable technology or high-throughput sequencing technology,which belong to important dominant microorganisms.