scholarly journals KARAKTERISTIK MORFOLOGI DAN FISIOLOGI BAKTERI ENDOFIT DAN RIZOBAKTERI DARI TANAMAN CENGKEH SEHAT

2021 ◽  
Vol 4 (1) ◽  
pp. 1-8
Author(s):  
Fina Dwimartina ◽  
Tri Joko ◽  
Triwidodo Arwiyanto

One of the determining factors in disease control is the use of superior seeds which have good quality and quantity. The use of biological control agents that form a symbiotic mutualism in their host plants can be used as an effort to obtain quality clove seeds. Endophytic bacteria and rhizobacteria have been reported as potential biological control agents for many plant diseases because of their safety in humans and non-target organisms. The purpose of this study was to identify the physiological and morphological characteristics of endophytic and rhizobacterial isolates obtained from clove plants. A total of 46 endophytic bacterial isolates were isolated from healthy clove roots, stems, leaves and flowers. Also, 66 isolates were isolated from the soil around the rhizosphere area. Based on the results of the identification of physiological and morphological characteristics, it is evident that the endophytic and rhizobacterial bacteria tested have the same character as Bacillus spp.

EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
James P. Cuda ◽  
Patricia Prade ◽  
Carey R. Minteer-Killian

In the late 1970s, Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), was targeted for classical biological control in Florida because its invasive properties (see Host Plants) are consistent with escape from natural enemies (Williams 1954), and there are no native Schinus spp. in North America. The lack of native close relatives should minimize the risk of damage to non-target plants from introduced biological control agents (Pemberton 2000). [...]


Nematology ◽  
2004 ◽  
Vol 6 (3) ◽  
pp. 375-387 ◽  
Author(s):  
N. Aileen Ryan ◽  
Peter Jones

AbstractSeventy bacteria, isolated from the rhizosphere of the potato cyst nematode (PCN) host plant, potato, were cultured in the presence and absence of potato root leachate (PRL) and the resultant culture filtrates were analysed for their ability to affect the hatch in vitro of the two PCN species. Of the isolates tested, nine had a significant effect on PCN hatch. Six affected Globodera pallida hatch and three affected G. rostochiensis hatch. Five of the isolates significantly increased hatch only when cultured in the presence of PRL. Three of the isolates decreased PCN hatch significantly in PRL. Only one isolate increased hatch significantly in the absence of PRL. No isolate affected the hatch of both species. Six of the nine isolates that significantly affected PCN hatch had been pre-selected by culturing on PRL. Bacterial isolates from PCN non-hosts (14 from wheat, 17 from sugar beet) were also tested for hatching activity. The principal effect of the hatch-active isolates from the PCN non-host plants was to increase PCN hatch in the presence of PRL. In contrast to the host bacteria results, the isolates from non-host plants affected only G. rostochiensis hatch (three wheat isolates and four sugar beet isolates significantly increased G. rostochiensis hatch); no such isolate affected G. pallida hatch significantly in the presence of PRL. Ten isolates (32%) from non-host plants had the ability to increase significantly the hatch of PCN in the absence of PRL (eight of these affected G. rostochiensis hatch and four affected G. pallida hatch), compared to only one bacterial isolate (1%) from a host plant. The majority of the isolates from non-hosts produced PCN species-specific effects, as with the bacteria isolated from potatoes, although two wheat isolates increased the hatch of both species significantly in the absence of PRL. Of 20 hatch-active bacterial isolates (from all three plants) identified, 70% were Bacillus spp. Other genera identified were Arthrobacter , Acinetobacter and Staphylococcus .


2008 ◽  
Vol 46 (1) ◽  
pp. 46-56 ◽  
Author(s):  
Rachel L. Melnick ◽  
Nina K. Zidack ◽  
Bryan A. Bailey ◽  
Siela N. Maximova ◽  
Mark Guiltinan ◽  
...  

Zootaxa ◽  
2011 ◽  
Vol 2921 (1) ◽  
pp. 13 ◽  
Author(s):  
ROBERT L. ZUPARKO ◽  
DALVA LUIZ DE QUEIROZ ◽  
JOHN LA SALLE

Tamarixia schina Zuparko sp. nov. and T. dahlsteni Zuparko sp. nov. are described. Both species have become established in California following their introductions from Chile and Australia, respectively, for control of invasive psyllids. Tamarixia schina is known from Calophya schini (Hemiptera: Calophyidae) on Schinus molle (Anacardiaceae) and T. dahlsteni from Trioza eugeniae (Hemiptera: Triozidae) on Syzygium paniculatum (Myrtaceae). The use of Tamarixia in biological control is discussed, and an annotated list of world species including distribution, hosts, and host plants, is provided. Tetrastichus atamiensis Ashmead is transferred to Tamarixia as Tamarixia atamiensis (Ashmead) comb. n.


2020 ◽  
Author(s):  
Andrew C. Wylie ◽  
Zamir K. Punja

Biological control of plant diseases is important in organic greenhouse vegetable production where fungicide use is limited. Organic producers employ microbially-diverse substrates, including composts, as media for plant growth. Previous research into the impact of vermicompost on the efficacy of applied biocontrol agents is limited. An in vitro assay was developed to test the efficacy of two biological control agents in a competitive microbial background. Suppression of the pathogen Fusarium oxysporum f. sp. radicis-cucumerinum (Forc) by Clonostachys rosea f. catenulata (Gliocladium catenulatum strain J1446 (Prestop®) and Bacillus subtilis strain QST 713 (Rhapsody®), was assessed on agar media amended with aerated vermicompost tea (ACT). Pathogen growth was reduced more by C. rosea than ACT alone and C. rosea was equally effective when combined with ACT. In contrast, B. subtilis reduced pathogen growth less than ACT, and when combined, reduced pathogen growth not more than ACT alone. Both biocontrol agents were similarly tested with ACT against Forc and Rhizoctonia solani on cucumber and radish. Additive, neutral, and antagonistic responses, depending on host, pathogen, and biocontrol agent, were observed. ACT alone provided more consistent disease suppression on cucumber compared with B. subtilis or C. rosea. In combination, disease suppression was most often better than each biocontrol alone but not better than ACT alone. ACT had antagonistic or additive interactions with C. rosea in the radish/R. solani pathosystem, depending on the experiment. The specific and general suppression of plant diseases by biological control agents in microbially-rich environments is variable and requires further study.


Author(s):  
Noviani Noviani ◽  
Meryany Ananda ◽  
I Nengah Suwastika

Cacao (Theobroma cacao L.) has potential to symbiosis with endophytic microbes. These microorganisms have a symbiotic mutualism with host plants. The group of endophytic bacteria are produce antibiotics, anti-cancer, anti-fungal, anti-viral, volatile compounds, even insecticides, while endophytic fungi is a biological control agents. This study were aimed to isolate and characterize bacteria and fungi that have the potential as endophytic microbes from Sulawesi's superior cacao (T. cacao L.). The method used in this study was descriptive method to determine the characterization of bacteria and fungi that have the potential as endophytic microbes, the results showed that there were 2 bacterial isolates who has a different morphology and 1 fungal isolate suspected genus Aspergilus.


2017 ◽  
pp. 261-269 ◽  
Author(s):  
Dragana Bjelic ◽  
Maja Ignjatov ◽  
Jelena Marinkovic ◽  
Nemanja Spremo ◽  
Maja Karaman ◽  
...  

Biocontrol using plant growth-promoting rhizobacteria (PGPR) represents an alternative approach to disease management, since PGPR are known to promote growth and reduce diseases in various crops. Among the different PGPR, members of the genus Bacillus are prefered for most biotechnological uses due to their capability to form extremely resistant spores and produce a wide variety of metabolites with antimicrobial activity. The objective of this research was to identify antagonistic bacteria for management of the plant diseases. Eleven isolates of Bacillus spp. were obtained from the soil samples collected from different localities in the Province of Vojvodina. The antifungal activity of bacterial isolates against five fungal species was examined using a dual plate assay. Bacillus isolates exhibited the highest antifungal activity against Fusarium proliferatum, Fusarium oxysporum f. sp. cepae and Alternaria padwickii, while they had the least antagonistic effect on Fusarium verticillioides and Fusarium graminearum. Molecular identification showed that effective bacterial isolates were identified as Bacillus safensis (B2), Bacillus pumilus (B3, B11), Bacillus subtilis (B5, B7) and Bacillus megaterium (B8, B9). The highest antagonistic activity was exhibited by isolates B5 (from 39% to 62% reduction in fungal growth) and B7 (from 40% to 71% reduction in fungal growth). These isolates of B. subtilis could be used as potential biocontrol agents of plant diseases.


2020 ◽  
Author(s):  
Francisco Daniel Hernández-Castillo ◽  
Francisco Castillo-Reyes ◽  
Marco Antonio Tucuch-Pérez ◽  
Roberto Arredondo-Valdes

This chapter will cover topics about the microbial antagonists Trichoderma spp. and Bacillus spp. from the perspective of use as potential biological control agents on plant diseases. Results obtained in the laboratory about from their isolation, microbial strain collections for both genera, taxonomic identification, antifungal activity in in vitro tests, obtained evaluation of the antifungal effect of secondary metabolites from microbial antagonists will be shown. Besides, results obtained from bioassays in the greenhouse and field are used as biopesticides in the control of diseases in fruit trees and vegetables and their effects on the promotion of plant growth and increased crop yield.


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