scholarly journals Evaluation of Soil-Applied Chemical Fungicide and Biofungicide for Control of the Fusarium Wilt of Chrysanthemum and Their Effects on Rhizosphere Soil Microbiota

Agriculture ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 184 ◽  
Author(s):  
Huijie Chen ◽  
Shuang Zhao ◽  
Kaikai Zhang ◽  
Jiamiao Zhao ◽  
Jing Jiang ◽  
...  

Chemical fungicides are a frequently used intervention for the control of the Fusarium wilt of chrysanthemum, but are no longer considered environmentally friendly. However, the biofungicides offer one of the best alternatives to reduce the use of chemical fungicides. In this study, a series of two-year greenhouse experiments were conducted to evaluate the soil-applied chemical fungicide (dazomet, DZ) and biofungicide (biocontrol agent combined with B. subtilis NCD-2, BF) for controlling the Fusarium wilt of chrysanthemum and its effects on rhizosphere soil microbiota. The results indicated that DZ and BF showed good control efficacy of Fusarium wilt of chrysanthemum in the two-year application evaluation. However, the DZ treatment significantly decreased the soil catalase and urease activities compared with the control, while BF showed a significant increase in bacterium/fungus ratios (B/F), soil urease and acid phosphatase activities. Abundances of potential plant pathogens F. oxysporum, Rhizoctonia zeae and Rhizoctonia solani were also lower, while potential plant-growth-promoting micro-organisms like the Rhizobiales bacterium and Mariniflexile sp. were higher in the BF treatment than in the control. Our findings suggested that the overall effect of the soil biota on chrysanthemum growth was more positive and stronger in the BF treatment than in the DZ treatment.

Author(s):  
Cun Yu ◽  
Ying Yao

Endophytic fungi were isolated from Phoebe bournei and their diversity and antimicrobial and plant growth-promoting activities were investigated. Of the 389 isolated endophytic fungi, 88.90% belonged to phylum Ascomycota and 11.10% to phylum Basidiomycota. The isolates were grouped into four taxonomic classes, 11 orders, 30 genera, and 45 species based on internal transcribed spacer sequencing and morphologic analysis. The host showed a strong affinity for the genera Diaporthe and Phyllosticta. The diversity of the fungi was highest in autumn, followed by spring and summer, and was lowest in winter. The fungi exhibited notable tissue specificity in P. bournei, and the species richness and diversity were highest in the root across all seasons. Five isolates showed antimicrobial activity against eight plant pathogens, and reduced the incidence of leaf spot disease in P. bournei. Additionally, 9 biocontrol isolates showed plant growth-promoting activity, with five significantly promoting P. bournei seedling growth. This is the first report on the endophytic fungi of P. bournei and their potential applicability to plant disease control and growth promotion.


2005 ◽  
Vol 82 (3) ◽  
pp. 85-102 ◽  
Author(s):  
C.L. Doumbou ◽  
M.K. Hamby Salove ◽  
D.L. Crawford ◽  
C. Beaulieu

Actinomycetes represent a high proportion of the soil microbial biomass and have the capacity to produce a wide variety of antibiotics and of extracellular enzymes. Several strains of actinomycetes have been found to protect plants against plant diseases. This review focuses on the potential of actinomycetes as (a) source of agroactive compounds, (b) plant growth promoting organisms, and (c) biocontrol tools of plant diseases. This review also addresses examples of biological control of fungal and bacterial plant pathogens by actinomycetes species which have already reached the market or are likely to be exploited commercially within the next few years.


2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 578-586 ◽  
Author(s):  
Munusamy Madhaiyan ◽  
Selvaraj Poonguzhali ◽  
Murugaiyan Senthilkumar ◽  
Dhandapani Pragatheswari ◽  
Jung-Sook Lee ◽  
...  

Three novel bacterial strains, designated Vu-144T, Vu-7 and Vu-35, were isolated on minimal medium from rhizosphere soil of field-grown cowpea and subjected to a taxonomic study using a polyphasic approach. Cells of the strains were Gram-stain-negative, non-motile, non-spore-forming, coccoid rods, and formed non-pigmented colonies. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Vu-144T was affiliated with an uncultivated lineage of the phylum Bacteroidetes . Its closest phylogenetic neighbour was the recently described species Niastella populi , a member of the family Chitinophagaceae , with just 90.7 % sequence similarity to the type strain. The only isoprenoid quinone detected was menaquinone 7 (MK-7). The fatty acid profiles showed large amounts of iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G and minor amounts of summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), C16 : 0 and other fatty acids, allowing the differentiation of the strains from other genera. The G+C content of the genomic DNA of the three strains ranged from 43.1 to 44.3 mol%. In addition to phosphatidylethanolamine, the major polar lipids were three unidentified aminophospholipids (APL1–APL3), two unidentified phospholipids (PL1, PL2) and three unidentified lipids (UL1–UL3). Biochemical test patterns also differed from those of Niastella populi and members of other genera. All three isolates showed plant-growth-promoting properties, e.g. the ability to produce indole-3-acetic acid and NH3 and to solubilize phosphate, utilized 1-aminocyclopropane 1-carboxylate (ACC) as a sole source of nitrogen and possessed the ACC deaminase enzyme. The novel isolates readily colonized roots and stimulated growth of tomato and cowpea under glasshouse conditions. Inoculated plants showed a 45–60 % increase in dry matter weight with respect to uninoculated controls. On the basis of the evidence from our polyphasic study, isolate Vu-144T represents a novel genus and species in the family Chitinophagaceae , for which the name Arachidicoccus rhizosphaerae gen. nov., sp. nov. is proposed. The type strain of Arachidicoccus rhizosphaerae is Vu-144T ( = KCTC 22378T = NCIMB 14473T).


2012 ◽  
Vol 1 (3) ◽  
pp. 251-257 ◽  
Author(s):  
Keshav Prasad Shukla ◽  
Shivesh Sharma ◽  
Nand Kumar Singh ◽  
Vasudha Singh

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