Endophytic Microbial Community Of The Healthy Banana Plant And Its Potential For Growth Promotion And Disease Control

Fusarium wilt of banana caused by the invasion of pathogenic,Fusairum oxysporum f.sp.cubense(FOC4)is the most destructive soil-borne disease which limits the sustainable development relevant industry.Biological control i.e.the application of bio-organic fertilizer plays important role in soil-borne disease control.Banana endophytes live in banana plant by an establishing a close and harmonious symbiosis with hoster that banana plant can provide the necessary living source to endophytes while the endophytes can produce phytohormone like compounds to regulate banana growth and increase its resistance to plant disease.In this study,we explored the difference of endophytic community between healthy and diseased banana palnts to clarify indicator endophytic microbes in healthy banana paints.Bananas were planted in different soils with different microbial sources to decipher the formation of endophytic community.Three endophytes were isolated and tested for banana growth promotion and disease control potential.The main results were obtained as follows:1.The endophytic communities in different parts of healthy and diseased banana plants were profiled through MiSeq high-throughput sequencing.Banana root had the highest community diversity and richness,followed by leaf and stem.The diversity and richness in root and stem of diseased banana plant was higher than that of healthy banana,though the difference of Shannon diversity of root was insignificant.The endophytic community patterns were significant different between the healthy and diseased banana plants.Delftia,Bacillus,Salinispora,Asticcacaulis,and Zoogloea were indicator genera in healthy banana plants which were not detected in the diseased banana plants.Banana plants selected microbial community to get into the plant in purpose.The endophytic community composition,diversity and richness of banana plants were closely related to their health levels.The invasion of pathogen reduced the prevention level of banana plants to the microbial community outside of the plants.2.Banana plants have different selective absorption capacity for bacteria in different growth environments.The relative abundance of endophyte in the root of banana plant is greatly influenced by the culture time,while they are relatively stable in stem and leave.Streptomyces?Agrobacterium?Chryseobacterium?Asticcacaulis?Azospirillum?Phenylobacterium?Pseudomonas?Pedobacter?Ochrobactrum?Flectobacillus?Zoogloea?Sphingomonas?Dechloromonas?Parabacteroides?Paenibacillus?Bacillus presents in all parts of banana plant.3.Three strains were isolated based on different bacterial morphologies which were further classified as Bacillus megaterium(BE1),Pseudomonas aeruginosa(BE2),and Paenibacillus amylolyticus(BE3)through 16S rRNA phylogenetic tree.The confrontation culture with pathogen suggests all the three strains have significant antagonism to FOC4.Hydroponics experiment comfirmed all these strains can promote banana growth by spray to the leaf or stem and inoculation to the root.In summary,the healthy and diseased banana plants had different endophytic community in root,stem,and leaf.Each part had their unique endophytic community.The endophytic communities in stem and leaf were relatively stable compared to that of root.Bacillus megaterium(BE1),Pseudomonas aeruginosa(BE2),and Paenibacillus amylolyticus(BE3)were isolated and these strains were comfirmed that can promote banana growth and have the potential for disease control.