Application of Bio‐Organic Fertilizer Significantly Affected Fungal Diversity of Soils

Abstract

Cotton verticillium wilt (Verticillium dahliae Kleb.) is a very destructive disease. In this study, we evaluated a Bacillus subtilis enhanced bio-organic fertilizer (BOF) for control of the disease and for its eff ect on rhizosphere microbiota. Greenhouse pot experiments were conducted during three cotton (Gossypium hirsutum L.) growing seasons with serial treatments of BOF or unenhanced organic fertilizer (OF). Consistent control of cotton verticillium wilt was obtained in the three trials. Th e complete BOF treatment, in which both nursery cups with healthy soils and transplanted pots with diseased soils were amended with BOF, was the most eff ective in reducing the counts of pathogenic V. dahliae and of total fungi in the cotton rhizosphere. Th e complete BOF treatment was also the most eff ective in reducing disease incidence. Rhizosphere soil DNA was extracted at harvest and the 5´ end (370 base pairs) of the fungal 18S rRNA gene was amplifi ed by using the primer pair NS1 and GCFung (fungus specifi c). Seventy-one bands were recognized in denaturing gradient gel electrophoresis (DGGE) gels and excised for sequencing, but only 35 bands were successfully sequenced during the study. Nonmetric multidimensional scaling analysis of DGGE patterns showed that the complete BOF treatments were not close to any other treatment. Ribotypes related to four Ascomycota and two Basidiomycota fungi were detected in the untreated but not in the BOF-amended soil. Th e results suggest that the complete BOF treatment could eff ectively control cotton verticillium wilt by signifi cantly improving fungal structure in rhizosphere soils.

Bio-organic Fertilizer Promotes Plant Growth and Yield and Improves Soil Microbial Community in Continuous Monoculture System of Chrysanthemum morifolium cv. Chuju

“…In a comparative study on different organic amendments, Shen et al (2013) found that bio-organic fertilizer was the most effective in improving soil microbial communities, suppressing Fusarium wilt disease in banana, and enhancing yield and quality of banana. Luo et al (2010) also showed that application of bio-organic fertilizer formulated with Bacillus subtilis biological control agent significantly improved fungal population composition in rhizosphere soils and effectively controlled cotton verticillium wilt. In our present experiments, bio-organic fertilizer showed significant roles in enhancing Chuju yield and quality and suppressing Fusarium population, but it is necessary to further examine bio-organic fertilizer impact on microbial community dynamics and its duration.…”

“…Bio-organic fertilizer is an organic amendment inoculated with living beneficial micro-organisms. It has showed better roles in improving plant growth and suppressing disease than common organic amendments have (Ahmad et al, 2008;Luo et al, 2010;Ding et al, 2013). In a comparative study on different organic amendments, Shen et al (2013) found that bio-organic fertilizer was the most effective in improving soil microbial communities, suppressing Fusarium wilt disease in banana, and enhancing yield and quality of banana.…”

“…Bio-organic fertilizer is organic composts from organic wastes (farm waste, city waste, poultry litter and industrial wastes) blended with living cells of beneficial microorganisms (Kramany et al, 2007;Ahmad et al, 2008;Luo et al, 2010;Naveed et al, 2015). The microorganisms could increase the uptake of soil nutrients by plants (Ahmad et al, 2008), improve soil microbial community and activities (Ding et al, 2013); and/or inhibit soil borne pathogens (Luo et al, 2010;Ding et al, 2013), thus enhancing plant growth and yields (Naveed et al, 2015).…”

“…The microorganisms could increase the uptake of soil nutrients by plants (Ahmad et al, 2008), improve soil microbial community and activities (Ding et al, 2013); and/or inhibit soil borne pathogens (Luo et al, 2010;Ding et al, 2013), thus enhancing plant growth and yields (Naveed et al, 2015). Srivastava and Govil (2007) found that biofertilizers significantly enhanced vegetative growth and improved floral characters of gladiolus cv.…”

“…American Beauty, and increased the total rhizospheric bacterial population, as compared to control. Luo et al (2010) observed that applying bio-organic fertilizer effectively suppressed cotton verticillium wilt via improving fungal community structure in rhizospheric soils.…”