scholarly journals Characterization of endophytic yeast and its suppressive effect on root rotting fungi of tomato under neem cake soil amendment

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Ayesha Jamal ◽  
Hafiza Farhat ◽  
Faizah Urooj ◽  
Afshan Rahman ◽  
Muhammed Irfan ◽  
...  
Keyword(s):  
Root Rot ◽  
Soil Amendment ◽  
Biocontrol Agent ◽  
Suppressive Effect ◽  
Economic Losses ◽  
Tomato Plants ◽  
Neem Cake ◽  
Root Rot Disease ◽  
Rot Disease

Abstract Background The exposure of crops to a variety of fungal and bacterial pathogens leads to huge economic losses. Different strategies are being adapted to control these diseases among which the application of chemicals fungicide is common. However, these chemicals are posing a serious threat to the environment. For biological management of root rot disease of tomato and better fruit quality, studies were conducted on the possible use of endophytic yeast as a biocontrol agent. Results Endophytic yeasts were isolated from healthy plants and identified. Identification of selected isolates was confirmed on the basis of 18S rDNA gene sequencing. They were evaluated for suppressive effect on root rotting fungi in vitro and also in vivo on tomato plants, used alone or under neem cake soil amendment. Seventy-six isolates of yeasts were evaluated against root rotting fungi Fusarium oxysporum, F. solani, Rhizoctonia solani and Macrophomina phaseolina using dual culture plate assay. Seventy-five isolates were found to suppress radial growth of F. oxysporum, F. solani and M. phaseolina by producing zones of inhibition or lysing the fungal hyphae. However, none of the isolates was found to inhibit R. solani in vitro. Most of the isolates also caused nematicidal activity at varying degree against Meloidogyne javanica. All test isolates produced indole acetic acid in vitro and solubilized phosphorus. In pots and field plot experiments, test isolates of yeasts were able to suppress root rotting fungi on tomato in natural soil and soil amended with neem cake with enhancement of growth of tomato plants. Yeasts were also found to ameliorate the plant resistance through enhancing polyphenolic contents, salicylic acid and antioxidant activity. Conclusions Endophytic yeasts were found effective against root rot disease of tomato and could be used as a potential biocontrol agent for the management of soil-borne diseases of tomatoes.

scholarly journals Bacillus megaterium-Mediated Synthesis of Selenium Nanoparticles and Their Antifungal Activity against Rhizoctonia solani in Faba Bean Plants

2021 ◽  
Vol 7 (3) ◽  
pp. 195
Author(s):  
Amr H. Hashem ◽  
Amer M. Abdelaziz ◽  
Ahmed A. Askar ◽  
Hossam M. Fouda ◽  
Ahmed M. A. Khalil ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Vicia Faba ◽  
Root Rot ◽  
Antifungal Agents ◽  
Damping Off ◽  
Growth Promoters ◽  
Root Rot Disease ◽  
Rot Disease

Rhizoctonia root-rot disease causes severe economic losses in a wide range of crops, including Vicia faba worldwide. Currently, biosynthesized nanoparticles have become super-growth promoters as well as antifungal agents. In this study, biosynthesized selenium nanoparticles (Se-NPs) have been examined as growth promoters as well as antifungal agents against Rhizoctonia solani RCMB 031001 in vitro and in vivo. Se-NPs were synthesized biologically by Bacillus megaterium ATCC 55000 and characterized by using UV-Vis spectroscopy, XRD, dynamic light scattering (DLS), and transmission electron microscopy (TEM) imaging. TEM and DLS images showed that Se-NPs are mono-dispersed spheres with a mean diameter of 41.2 nm. Se-NPs improved healthy Vicia faba cv. Giza 716 seed germination, morphological, metabolic indicators, and yield. Furthermore, Se-NPs exhibited influential antifungal activity against R. solani in vitro as well as in vivo. Results revealed that minimum inhibition and minimum fungicidal concentrations of Se-NPs were 0.0625 and 1 mM, respectively. Moreover, Se-NPs were able to decrease the pre-and post-emergence of R. solani damping-off and minimize the severity of root rot disease. The most effective treatment method is found when soaking and spraying were used with each other followed by spraying and then soaking individually. Likewise, Se-NPs improve morphological and metabolic indicators and yield significantly compared with infected control. In conclusion, biosynthesized Se-NPs by B. megaterium ATCC 55000 are a promising and effective agent against R. solani damping-off and root rot diseases in Vicia faba as well as plant growth inducer.

scholarly journals Structure and function of rhizosphere and root endophyte microbial communities associated with healthy and root rot diseased Panax notoginseng

2021 ◽  
Author(s):  
Pan Pan Wang ◽  
Li Fang Yang ◽  
Jia Ling Sun ◽  
Ye Yang ◽  
Yuan Qu ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Pseudomonas Fluorescens ◽  
Root Rot ◽  
Panax Notoginseng ◽  
Economic Losses ◽  
Root Endophyte ◽  
Variovorax Paradoxus ◽  
Root Rot Disease ◽  
Functional Pathways ◽  
Rot Disease

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.

scholarly journals In vitro: stem cutting a simple technique for determination aggressive potential of fungal isolates causing root rot disease of grapevine

2020 ◽  
Vol 11 (1) ◽  
pp. 141-147
Author(s):  
El- Sayed Hussein Ziedan ◽  
Moataza Mahmoud Saad ◽  
Khames Ahmed Hemida ◽  
Mohamed Abd El- Aziz El -Naggar ◽  
Mostafa Helmy Mostafa ◽  
...  
Keyword(s):  
Root Rot ◽  
Simple Technique ◽  
Stem Cutting ◽  
Root Rot Disease ◽  
Fungal Isolates ◽  
Rot Disease

Antifungal activity of plant extracts against Embellisia astragali, the fungal causal agent of yellow dwarf and root-rot disease of standing milkvetch

2015 ◽  
Vol 66 (7) ◽  
pp. 735 ◽  
Author(s):  
Cuiyun Zeng ◽  
Xiaoyu Zhu ◽  
Zhen Cui ◽  
Yanzhong Li
Keyword(s):  
Antifungal Activity ◽  
Root Rot ◽  
Juglans Regia ◽  
Yellow Dwarf ◽  
Root Rot Disease ◽  
Ethanolic Extracts ◽  
Rot Disease ◽  
Causative Fungus ◽  
Saposhnikovia Divaricata

In an attempt to find biological fungicides, we screened 18 medicinal plants used in Chinese traditional medicine for their activity against Embellisia astragali, the causative fungus of yellow dwarf and root-rot disease in standing milkvetch (Astragalus adsurgens Pall.). The antifungal efficacy of ethanolic extracts of these plants was tested in vitro. Our results show that among the 18 plants tested, the ethanolic extracts of Saposhnikovia divaricata, Allium sativum and Juglans regia totally inhibited mycelial growth of E. astragali. These three extracts also significantly inhibited spore germination of E. astragali, with inhibition rates ranging from 86% to 88%. In addition, the same extract from the same plant part indicated the strongest antifungal activity against E. astragali, with a minimal inhibitory concentration value of 50 mg mL–1. These results demonstrate that plant-derived products have a high potential to control yellow dwarf and root-rot disease in standing milkvetch.

Impact of chitosan seed treatment of fenugreek for management of root rot disease caused by Fusarium solani under in vitro and in vivo conditions

3 Biotech ◽  
2021 ◽  
Vol 11 (6) ◽  
Author(s):  
Mahesh R. Ghule ◽  
Purushottam K. Ramteke ◽  
Sahadeo D. Ramteke ◽  
Prasad S. Kodre ◽  
Amruta Langote ◽  
...  
Keyword(s):  
Fusarium Solani ◽  
Root Rot ◽  
Seed Treatment ◽  
Root Rot Disease ◽  
Rot Disease

scholarly journals Complete Genome Resource of Bacillus velezensis J17-4, an Endophyte Isolated from Stem Tissues of Rice

Plant Disease ◽  
2021 ◽  
Author(s):  
Z.R. Shi ◽  
Wanwen Hong ◽  
Qingwei Wang
Keyword(s):  
Root Rot ◽  
Complete Genome ◽  
Gene Clusters ◽  
Underlying Mechanism ◽  
Economic Losses ◽  
Bacillus Velezensis ◽  
Circular Chromosome ◽  
Root Rot Disease ◽  
Genome Data ◽  
Rot Disease

Dickeya zeae is the causative agent of rice root rot disease and causes severe harvest and economic losses. In this study, the Bacillus velezensis strain J17-4 with significant antagonist against D. zeae was used to generate DNA for sequencing. After assembly, a high-quality complete genome comprising only a circular chromosome was available. The genome sequence consists of a total of 3877 prediction coding sequences and nine types of gene clusters involved in secondary metabolite production. This genome data will provide information for understanding the underlying mechanism of strain J17-4 antagonist against D. zeae and a new useful source for comparative genomics studies between strains isolated from various habitats.

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