Construction of a Recombinant Bacillus velezensis Strain as an Integrated Control Agent Against Plant Diseases and Insect Pests

2009 ◽  
Vol 19 (10) ◽  
pp. 1223-1229 ◽  
Author(s):  
Jong Yul Roh
Keyword(s):  
Insect Pests ◽  
Integrated Control ◽  
Control Agent ◽  
Plant Diseases ◽  
Bacillus Velezensis

scholarly journals Efficacy of the parasitoid, Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) on the cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) egg masses

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Hend O. Mohamed
Keyword(s):  
Spodoptera Littoralis ◽  
Insect Pests ◽  
Single Layer ◽  
Control Agent ◽  
Physical Characteristics ◽  
Great Ability ◽  
Egg Masses ◽  
Cotton Leafworm ◽  
Lepidoptera Noctuidae ◽  
Trichogrammatoidea Bactrae

Abstract Background The Egyptian cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) is one of the major insect pests, causing a significant damage on different cultivated agricultural crops. Developing an alternative non-chemical tool, an effective and environmentally friendly method to suppress pest's infestation is essentially needed. Therefore, biological control by releasing the egg parasitoids could be the most promising tool for integrated pest management. Results This study was designed to evaluate the efficacy of the egg parasitoid, Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) as a bio-control agent against S. littoralis egg masses with different physical characteristics (number of egg layer and degree of scale density) in a no-choice and choice tests, under laboratory conditions. Also, the parasitoids’ fitness in terms of parasitism percentage, developmental period, adults’ emergence percentage, female offspring percentage, and longevity were investigated. The results revealed that T. bactrae wasps had a great ability to parasitize S. littoralis egg masses, but with different rates, related to their layers and scales’ thickness in both tests. The highest parasitism percentage was observed on one-layer eggs, followed by two layers. However, 3-layer eggs were the least preferable one. High numbers of adult emergencies (> 80%) were observed in all tested egg masses, except in the case of 3 layers with high scales. Furthermore, female-biased sex ratios were noticed at all examined eggs, with only the exception of high-scaly eggs with a single layer that recorded the lowest rate (≤ 45%). Besides, the survival of adult female parasitoids was not significantly affected in both tests. Conclusions T. bactrae could be used as a bio-control agent against S. littoralis egg masses with different physical characteristics based on the achieved results.

scholarly journals Could Gnomoniopsis castaneae Be Used as a Biological Control Agent against Insect Pests?

2021 ◽  
Vol 11 (9) ◽  
pp. 4066
Author(s):  
Spiridon Mantzoukas ◽  
Ioannis Lagogiannis ◽  
Aristeidis Ntoukas ◽  
George T. Tziros ◽  
Konstantinos Poulas ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Brown Rot ◽  
Control Agent ◽  
Effective Control ◽  
Mortality Factor ◽  
Perennial Crop ◽  
Gall Wasp ◽  
Pathogenic Potential

Gnomoniopsis castaneae is the cause of the chestnut brown rot but has been also regarded as an important mortality factor for the chestnut gall wasp Dryocosmus kuriphilus. The question to whether G. castaneae could serve as a natural biocontrol agent against insect pests is investigated in the present study. We used three serious insect pests as experimental model insects: Plodia interpuctella and Trogoderma granarium, which are important pests of stored products, and Myzus persicae, a cosmopolitan, serious pest of annual and perennial crop plants. Although chemical pesticides represent effective control means, they are also related to several environmental and health risks. In search for alternative pest management methods, scientific interest has been focused, inter alia, on the use of entomopathogenic fungi. While Isaria fumosorosea has long been recognized as an effective control agent against several pests, G.castaneae has been very little studied. The present study examined whether and to what extent G. castaneae and I. fumosorosea exhibit insecticidal activity against fourth-instar larvae of P. interpunctella and T. granarium and adults of M. persicae. Mortality was examined in interrelation with dosage and time exposure intervals. Both fungi exhibited pesticidal action. However, G. castaneae induced noteworthy mortality only at very high doses. In general, we concluded that G. castaneae failed to cause high insect pathogenicity at normal doses and may not be an efficient biocontrol agent compared with other entomopathogens. On the other hand, our study reiterates the pathogenic potential of I. fumosorosea. More studies are needed to further our insight into the potential of EF species as a component of IPM.

scholarly journals Seasonal Variation of Tannin and Nutrient in Aegiceras corniculatum Leaves in Zhangjiang Mangrove Ecosystem

2015 ◽  
Vol 9 (1) ◽  
pp. 143-148
Author(s):  
Minshen Huang ◽  
Lihua Zhang ◽  
Shudong Wei ◽  
Qi Zeng ◽  
Haichao Zhou ◽  
...  
Keyword(s):  
Condensed Tannins ◽  
Insect Pests ◽  
Mangrove Ecosystem ◽  
Plant Diseases ◽  
The Sun ◽  
Aegiceras Corniculatum ◽  
Significant Difference ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

Seasonal dynamics of total phenolics (TP), extractable condensed tannins (ECT), protein-bound condensed tannins (PBCT), fiber-bound condensed tannins (FBCT), total condensed tannins (TCT) and nitrogen contents in sun and shade leaves of Aegiceras corniculatum were studied in the Zhangjiang Estuary, Fujian Province, China. The contents of TP, ECT and TCT in the sun leaves were significantly higher than those in the shade leaves through the season. The N content in sun leaves was higher than that in shade leaves in the autumn, while it was lower in the summer, and there was no significant difference in the winter and spring. With the respect to the P through the year, P content in the sun leaves was different between seasons, with the highest in winter and the lowest in summer. In addition, the TP:N and ECT:N ratios in sun leaves were significantly higher than those in shade leaves except in autumn. High tannin levels and TP:N and ECT:N ratios in the sun leaves not only can reduce oxidative stress, but also improve the ability of resisting plant diseases and insect pests.

scholarly journals Crop Protection against Botrytis cinerea by Rhizhosphere Biological Control Agent Bacillus velezensis XT1

2020 ◽  
Vol 8 (7) ◽  
pp. 992 ◽  
Author(s):  
Laura Toral ◽  
Miguel Rodríguez ◽  
Victoria Béjar ◽  
Inmaculada Sampedro
Keyword(s):  
Defense Mechanisms ◽  
Biological Control Agent ◽  
Disease Incidence ◽  
Crop Protection ◽  
Preventive Treatment ◽  
Control Agent ◽  
Total Biomass ◽  
Hormone Regulation ◽  
Bacillus Velezensis ◽  
Callose Deposition

This study aims to evaluate the use of Bacillus velezensis strain XT1 as a plant growth-promoting rhizobacterium (PGPR) and biocontrol agent against B. cinerea in tomato and strawberry plants. Foliar and radicular applications of strain XT1 increased plant total biomass as compared to the control and B. cinerea-infected plants, with root applications being, on the whole, the most effective mode of treatment. Applications of the bacterium were found to reduce infection parameters such as disease incidence and severity by 50% and 60%, respectively. We analyzed stress parameters and phytohormone content in order to evaluate the capacity of XT1 to activate the defense system through phytohormonal regulation. Overall, the application of XT1 reduced oxidative damage, while the H2O2 and malondialdehyde (MDA) content was lower in XT1-treated and B. cinerea-infected plants as compared to non-XT1-treated plants. Moreover, treatment with XT1 induced callose deposition, thus boosting the response to pathogenic infection. The results of this study suggest that the signaling and activation pathways involved in defense mechanisms are mediated by jasmonic acid (JA) and ethylene hormones, which are induced by preventive treatment with XT1. The study also highlights the potential of preventive applications of strain XT1 to activate defense mechanisms in strawberry and tomato plants through hormone regulation.

scholarly journals Pepper Bacterial Spot Control by Bacillus velezensis: Bioprocess Solution

2020 ◽  
Vol 8 (10) ◽  
pp. 1463
Author(s):  
Ivana Pajčin ◽  
Vanja Vlajkov ◽  
Marcus Frohme ◽  
Sergii Grebinyk ◽  
Mila Grahovac ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
Plant Protection ◽  
Medium Composition ◽  
Plant Diseases ◽  
Mass Spectrometry Analysis ◽  
Economic Losses ◽  
In Planta ◽  
Bacterial Spot ◽  
Bacillus Velezensis ◽  
Food Isolate

Pepper bacterial spot is one of the most severe plant diseases in terms of infection persistence and economic losses when it comes to fresh pepper fruits used in nutrition and industrial processing. In this study, Bacillus velezensis IP22 isolated from fresh cheese was used as a biocontrol agent of pepper bacterial spot, whose main causal agent is the cosmopolitan pathogen Xanthomonas euvesicatoria. After optimization of the cultivation medium composition aimed at maximizing of the antimicrobial activity against X. euvesicatoria and validation of the optimized medium at the scale of a laboratory bioreactor, in planta tests were performed. The results have showed significant suppression of bacterial spot symptoms in pepper plants by the produced biocontrol agent, as well as reduction of disease spreading on the healthy (uninoculated) pepper leaves. Furthermore, HPLC-MS (high pressure liquid chromatography–mass spectrometry) analysis was employed to examine antimicrobial metabolites produced by B. velezensis IP22, where lipopeptides were found with similar m/z values compared to lipopeptides from fengycin and locillomycin families. The bioprocess solution developed at the laboratory scale investigated in this study represents a promising strategy for production of pepper bacterial spot biocontrol agent based on B. velezensis IP22, a food isolate with a great perspective for application in plant protection.

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