Studies on Minimedusa Polyspora, a Biological Control Agent of Soilborne Plant Pathogens

The mechanism by which Chaetomium globosum, applied as ascospores to squash, snap bean, and pea seeds, reduces damage caused by larvae of the seed-corn maggot, Hylemya platura (Meigen), and soilborne plant pathogens was investigated. Chaetomium globosum ascospores germinate rapidly and cover the seed coat with a dense mat of mycelium soon after seeds are planted in soil. However, if seeds are not treated with C. globosum before planting, other organisms rapidly colonize the seed coat during germination. Seed flies oviposit near seeds in response to the growth of pseudomonads on the seed surface. Studies employing a selective medium indicate that Pseudomonas become the most prevalent genus occurring on the seed coat during seed germination. Treatment of seed with C. globosum suppresses the logarithmic growth of pseudomonads on the seed coat but affects neither bacterial populations in the soil surrounding the seed nor germination of Fusarium solani f. sp. pisi chlamydospores, either on the seed coat or in the soil surrounding the seed. A water-insoluble antibiotic was extracted from C. globosum treated seeds. After systemtic examination of other possibilities, it was concluded that this nondiffusable antibiotic substance produced by C. globosum suppresses pseudomonads responsible for stimulation of oviposition by seed flies as well as the soilborne plant pathogens.

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The Mode of Action of Bacillus Species against Fusarium graminearum, Tools for Investigation, and Future Prospects

Toxins ◽

10.3390/toxins11100606 ◽

2019 ◽

Vol 11 (10) ◽

pp. 606 ◽

Cited By ~ 6

Author(s):

Khayalethu Ntushelo ◽

Lesiba Klaas Ledwaba ◽

Molemi Evelyn Rauwane ◽

Oluwafemi Ayodeji Adebo ◽

Patrick Berka Njobeh

Keyword(s):

Biological Control ◽

Fusarium Graminearum ◽

Plant Pathogens ◽

Biological Control Agent ◽

Control Agent ◽

Fungal Species ◽

Bacillus Species ◽

Future Studies ◽

Biochemical Processes ◽

Analytical Platforms

Fusarium graminearum is a pervasive plant pathogenic fungal species. Biological control agents employ various strategies to weaken their targets, as shown by Bacillus species, which adopt various mechanisms, including the production of bioactive compounds, to inhibit the growth of F. graminearum. Various efforts to uncover the antagonistic mechanisms of Bacillus against F. graminearum have been undertaken and have yielded a plethora of data available in the current literature. This perspective article attempts to provide a unified record of these interesting findings. The authors provide background knowledge on the use of Bacillus as a biocontrol agent as well as details on techniques and tools for studying the antagonistic mechanism of Bacillus against F. graminearum. Emphasizing its potential as a future biological control agent with extensive use, the authors encourage future studies on Bacillus as a useful antagonist of F. graminearum and other plant pathogens. It is also recommended to take advantage of the newly invented analytical platforms for studying biochemical processes to understand the mechanism of action of Bacillus against plant pathogens in general.

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The Inability of Spotted Lanternfly (Lycorma delicatula) to Vector a Plant Pathogen between its Preferred Host, Ailanthus altissima, in a Laboratory Setting

Insects ◽

10.3390/insects11080515 ◽

2020 ◽

Vol 11 (8) ◽

pp. 515

Author(s):

Rachel K. Brooks ◽

Ashley Toland ◽

Andrew C. Dechaine ◽

Thomas McAvoy ◽

Scott Salom

Keyword(s):

Biological Control ◽

Plant Pathogens ◽

Biological Control Agent ◽

Life Stage ◽

Later Life ◽

Control Agent ◽

Ailanthus Altissima ◽

Future Research ◽

Laboratory Setting ◽

Lycorma Delicatula

With the recent introduction of the non-native spotted lanternfly (Lycorma delicatula) to the USA, research and concern regarding this insect is increasing. Though L. delicatula is able to feed on many different plant species, its preference for the invasive tree-of-heaven (Ailanthus altissima) is apparent, especially during its later life stage. Therefore, management focused on A. altissima control to help limit L. delicatula establishment and population growth has become popular. Unfortunately, the control of A. altissima is difficult. Verticillium nonalfalfae, a naturally occurring vascular-wilt pathogen, has recently received attention as a potential biological control agent. Therefore, we studied if L. delicatula fourth instars or adults could vector V. nonalfalfae from infected A. altissima material to healthy A. altissima seedlings in a laboratory setting. We were unable to re-isolate V. nonalfalfae from the 45 A. altissima seedlings or from the 225 L. delicatula utilized in this experiment. We therefore, found no support that L. delicatula could effectively vector this pathogen between A. altissima in laboratory conditions. Since L.delicatula’s ability to vector V. nonalfalfae has implications for the dissemination of both this beneficial biological control and other similar unwanted plant pathogens, future research is needed to confirm these findings in a field setting.

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