scholarly journals In-vitro compatibility assay of indigenous Trichoderma and Pseudomonas species and their antagonistic activities against black root rot disease (Fusarium solani) of faba bean (Vicia faba L.)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Alemayehu Dugassa ◽  
Tesfaye Alemu ◽  
Yitbarek Woldehawariat

Abstract Background Faba bean (Vicia faba L.) cultivation is highly challenged by faba bean black root rot disease (Fusarium solani) in high lands of Ethiopia. To ensure sustainable production of faba beans, searching for eco-friendly disease management options is necessary to curb the progress of the disease timely. The indigenous biocontrol agents that suit local environments may effectively strive with in-situ microorganisms and suppress local pathogen strains. This study aimed to screen antagonistic indigenous compatible Trichoderma and Pseudomonas strains against Fusarium solani. In the pathogenicity test, soil-filled pots were arranged in complete random block design and sown with health faba bean seeds. The effect of some fungicides was evaluated against Fusarium by food poisoning methods to compare with the biocontrol agents. The antagonistic efficacy of biocontrol agents and their compatibility was investigated on Potato dextrose agar medium. Results Fusarium solani AAUF51 strain caused an intense root rotting in faba bean plant. The effect of Mancozeb 80% WP at 300 ppm was comparable with Trichoderma and Pseudomonas strains against Fusarium. The mycelial growth of test the pathogen was significantly (P ≤ 0.05) reduced to 86.67 and 85.19% by Trichoderma harzianum AAUW1 and Trichoderma viridae AAUC22 strains in dual culture, respectively. The volatile metabolites of Pseudomonas aeruginosa AAUS31 (77.78%) found the most efficient in reducing mycelial growth of Fusarium followed by Pseudomonas fluorescens AAUPF62 (71.11%) strains. The cell-free culture filtrates of Pseudomonas fluorescens AAUPF62 and Pseudomonas aeruginosa AAUS31 were more efficient than the Trichoderma strain in reducing the growth of Fusarium isolates. There was no zone of inhibition recorded between Trichoderma harzianum AAUW1, Trichoderma viridae AAUC22, Pseudomonas aeruginosa AAUS31, and Pseudomonas fluorescens AAUPF62 strains, hence they were mutually compatible. Conclusions The compatible Trichoderma and Pseudomonas strains showed antagonistic potentiality that could be explored for faba bean protection against black root rot disease and might have a future dual application as biocontrol agents.

2016 ◽  
Vol 8 (2) ◽  
pp. 849-854
Author(s):  
M. Singh ◽  
Sushil Sharma ◽  
Mukesh Kumar

An experiment was carried out to find out the effective management practices to control the recently recorded pathogen (Fusarium solani) inciting root rot disease in Bael. Rampant incidence due to this pathogen is resulting in excess damage and reduction in acreage. Out of six fungicides screened in vitro, Topsin-M and Bavistin stood at first place in inhibiting the mycelial growth of F. solani. Topsin-M showed 100% inhibition at 50 ppm concentration whereas Bavistin showed 100% inhibition at 150 ppm concentration. Bavistin and Topsin-M as seed dressers effectively protected pre and post emergence seedlings mortality to the tune of 68.75 and 70.95%; 65.00 and 67.54%, respectively. Pre-sowing drenching of soil with Bavistin (0.4%) reduced the pre-emergence mortality from 26.50 to 8.25% and post-emergence mortality from 39.00 to 16.25%. The integration of seed treatment and pre-sowing drenching resulted in 72.51% control of pre emergence mortality and 82.92% control of post emergence mortality. In dual culture method, maximum inhibition of mycelial growth was recorded with Trichoderma harzianum (72.18%) followed by T. viride (67.70%). Glomus mosseae in combination with T. harzianum was found very effective against F. solani under screen house conditions as minimum pre emergence mortality (10.00%) and post emergence mortality (13.25%) against control where the values were 27.25% and 40.25%, respectively. The studies and results compiled here in provide an explanation for the potential of selected fungicides and antagonists in the control of bael root rot disease.


2013 ◽  
Vol 53 (3) ◽  
pp. 295-300 ◽  
Author(s):  
Nashwa Atef Sallam ◽  
Shaimaa Nagy Riad ◽  
Mohamed Samy Mohamed ◽  
Ahmed Seef El-eslam

Abstract The aim of this study was to evaluate the different carrier formulations of antagonistic bacteria on incidence of root rot disease of cantaloupe. Twenty-seven isolates of bacteria isolated from rizosphere cantaloupe plants (collected from different localities of the Assiut Governorate, Egypt) were tested in vitro against the growth of Fusarium solani. The tested isolates exhibited varied percentages of mycelial inhibition of F. solani. The highly antagonistic bacteria isolates were identified as Bacillus subtilis, Bacillus cereus, and Pseudomonas fluorescens. The effect of talc based powder and wood flour as various carrier formulations of antagonistic bacteria were tested on incidence of cantaloupe root rot disease in greenhouse and field experiments. All tested carrier formulations of antagonistic bacteria significantly decreased the disease index percentage (p > 0.05) of root rot disease compared with the control, in greenhouse or in field experiments. Application of the wood flour formulation to the infested soil at the time of planting, gave the lowest disease (21.75%) index percentage compared to an application fifteen days before planting (26.83%). The reverse effect occurred in the case of the talc based powder formulation application. In field experiments, during the two growing seasons of 2009 and 2010, wood flour formulation gave the same effect in the reduction of the disease index when added before planting or at the time of planting to soil infested with the pathogen. However, application of the talc formulation at the time of planting showed the least disease index compared to when it was applied fifteen days before planting. In general, wood flour formulation significantly decreased the disease index when compared with the talc formulation. In all the formulations, a number of viable colonies of bioagents were decreased gradually by prolonging the storage time at 4°C. Storage time was prolonged up to five months. But in the case of B. subtilis on talc and B. cereus on wood flour formulations, storage time needed to be prolonged up to seven months


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Farid Abd-El-Kareem ◽  
Ibrahim E. Elshahawy ◽  
Mahfouz M. M. Abd-Elgawad

Abstract Background Black root rot of strawberry plants caused by Rhizoctonia solani, Fusarium solani, and Pythium sp. is a serious disease in Egypt. Biocontrol agents have frequently proved to possess paramount and safe tools against many diseases. The impact of soil treatments with 3 Bacillus pumilus isolates on black root rot disease of strawberry plants caused by R. solani, F., and Pythium sp. under laboratory and field conditions was examined herein on the commonly used ‘Festival’ strawberry cultivar. To increase the bacterial adhesion and distribution on the roots, each seedling was dipped in bacterial cell suspension at 1 × 108 colony-forming units/ml of each separate bacterial isolate for 30 min then mixed with 5% Arabic gum. Results The tested B. pumilus isolates significantly reduced the growth area of these 3 fungi. The two bacterial isolates Nos. 2 and 3 reduced the growth area by more than 85.2, 83.6, and 89.0% for R. solani, F. solani, and Pythium sp., respectively. Likewise, the 3 bacterial isolates significantly (P ≤ 0.05) inhibited the disease under field conditions. Isolates Nos. 2 and 3 suppressed the disease incidence by 64.4 and 68.9% and disease severity by 65.3 and 67.3%, respectively. The fungicide Actamyl had effect similar to that of the 2 isolates. B. pumilus isolates significantly enhanced growth parameters and yields of strawberry plants; isolates Nos. 2 and 3 raised the yield by 66.7 and 73.3%, respectively. Conclusions Bacillus pumilus isolates could effectively manage the black rot disease in strawberry herein. Due to the significant impact of the root rot disease on strawberry yield, B. pumilus should be further tested to manage the disease on strawberry on large scale in Egypt.


2003 ◽  
Vol 83 (4) ◽  
pp. 939-942 ◽  
Author(s):  
H. M. Haji ◽  
R. A. Brammall ◽  
D. L. VanHooren

The effects of Nicotiana debneyi-derived resistance to black root rot disease were evaluated for yield, agronomic and quality traits by comparing the near isogenic cultivars AC Gayed (resistant) and Delgold (susceptible). Over 7 yr of trials the possession of resistance led to yields and economic returns that averaged 6 and 7% lower, respectively, than for the susceptible line. Key words: Flue-cured tobacco, Nicotiana tabaccum, Black Root Rot, Chalara elegans, Nicotiana debneyi, yield, quality


2021 ◽  
Author(s):  
Pan Pan Wang ◽  
Li Fang Yang ◽  
Jia Ling Sun ◽  
Ye Yang ◽  
Yuan Qu ◽  
...  

Abstract Background: Panax notoginseng (Burkill) F. H. Chen is a Chinese medicinal plant of the Araliaceae family commonly used in the treatment of cardiovascular and cerebrovascular diseases in Asia and elsewhere. To meet an increase in Chinese herbal medicine market demand, most P. notoginseng is planted artificially, and is vulnerable to various plant diseases. Root rot disease, in particular, causes substantial P. notoginseng yield reduction and economic losses. High-depth next-generation sequencing technology was used to analyze the rhizosphere and root endophyte microbial communities of P. notoginseng to compare the characteristics of these two communities between healthy and root rot diseased P. notoginseng plants, and to clarify the relationship between these microbial communities and root rot disease.Results: The P. notoginseng rhizosphere microbial community was more diverse than the root endophyte community, and the difference in functional pathways between healthy and diseased P. notoginseng plants was greater in the root endophyte than in the rhizosphere communities. Multi-database annotation results showed that the highest number of endophytic bacteria occurred in the roots of diseased plants. The number of carbohydrate-active enzymes database families was also higher in diseased roots. The RND antibiotic efflux function was higher in the healthy samples. A high abundance of Variovorax paradoxus and Pseudomonas fluorescens occurred in the healthy and diseased root endophyte communities, respectively. Ilyonectria mors-panacis and Pseudopyrenochaeta lycopersici were most abundant in the diseased samples. In addition, the complete genome of two unknown Flavobacteriaceae species and one unknown Bacteroides species were obtained based on binning analysis.Conclusions: The rhizosphere and root endophyte microbial communities of healthy and root rot diseased P. notoginseng showed marked differences in diversity and functional pathways. The higher mapping values obtained for the diseased samples reflected the occurrence of root rot disease at the molecular level. Variovorax paradoxus and Pseudomonas fluorescens may be antagonistic bacteria of root rot in P. notoginseng, whereas Ilyonectria mors-panacis and Pseudopyrenochaeta lycopersici appear to be P. notoginseng root rot pathogens. Our study provides a theoretical basis for understanding the occurrence of root rot in P. notoginseng and for further research on potential biological control agents.


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