@article{hansel_saville_ristaino_2024, title={Evaluation of a Formulation of <i>Bacillus subtilis</i> for Control of Phytophthora Blight of Bell Pepper}, volume={4}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-04-23-0807-RE}, abstractNote={Phytophthora blight, caused by Phytophthora capsici, is one of the most economically significant diseases of bell pepper in the United States. Over the past several decades, isolates of P. capsici exhibiting resistance to mefenoxam and other fungicides have been reported. Fungicide resistance coupled with an increased market for organically grown crops has led to interest in biological control as a disease management option. In this work, an isolate of Bacillus subtilis (AFS032321) was evaluated for control of Phytophthora blight of bell pepper in the greenhouse and field. A 28% active ingredient wettable powder formulation of the strain was applied as a soil drench at transplanting prior to inoculation. Treatment with this formulation of B. subtilis significantly reduced the area under the disease progress curve (AUDPC) by up to 52% compared to untreated control plants in greenhouse tests. Comparisons between applying the biocontrol weekly after seeding for 5 weeks versus a single application at transplanting (5 weeks) indicated no significant benefits of additional applications. The formulation of B. subtilis reduced disease caused by a mefenoxam-resistant isolate of P. capsici, while mefenoxam failed. The biocontrol efficacy of formulated strains was not affected in different soil types or potting media. However, disease was more severe in sandy soils. In field experiments that were conducted with a mefenoxam-sensitive isolate, disease incidence and severity of Phytophthora blight were significantly reduced at all rates of B. subtilis in 2019 except the 16.8 kg ha-1 rate. In both years, mefenoxam was more effective than B. subtilis in controlling disease in the field. B. subtilis did not affect the spatial dynamics of pathogen spread within rows. While the precise mechanism(s) of action is unclear, in vitro dual-culture tests suggest direct antagonism, as B. subtilis significantly inhibited colony growth of P. capsici. AgBiome has recently released a new formulation of the AFS032321 strain named Theia, with higher active ingredients for commercial applications and biocontrol of P. capsici.}, journal={PLANT DISEASE}, author={Hansel, Jeana and Saville, Amanda C. and Ristaino, Jean Beagle}, year={2024}, month={Apr} }
 @article{paul_saville_hansel_ye_ball_williams_chang_chen_gu_ristaino_et al._2019, title={Extraction of Plant DNA by Microneedle Patch for Rapid Detection of Plant Diseases}, volume={13}, ISSN={1936-0851 1936-086X}, url={http://dx.doi.org/10.1021/acsnano.9b00193}, DOI={10.1021/acsnano.9b00193}, abstractNote={In-field molecular diagnosis of plant diseases via nucleic acid amplification is currently limited by cumbersome protocols for extracting and isolating pathogenic DNA from plant tissues. To address this challenge, a rapid plant DNA extraction method was developed using a disposable polymeric microneedle (MN) patch. By applying MN patches on plant leaves, amplification-assay-ready DNA can be extracted within a minute from different plant species. MN-extracted DNA was used for direct polymerase chain reaction amplification of plant plastid DNA without purification. Furthermore, using this patch device, extraction of plant pathogen DNA ( Phytophthora infestans) from both laboratory-inoculated and field-infected leaf samples was performed for detection of late blight disease in tomato. MN extraction achieved 100% detection rate of late blight infections for samples after 3 days of inoculation when compared to the conventional gold standard cetyltrimethylammonium bromide (CTAB)-based DNA extraction method and 100% detection rate for all blind field samples tested. This simple, cell-lysis-free, and purification-free DNA extraction method could be a transformative approach to facilitate rapid sample preparation for molecular diagnosis of various plant diseases directly in the field.}, number={6}, journal={ACS Nano}, publisher={American Chemical Society (ACS)}, author={Paul, Rajesh and Saville, Amanda C. and Hansel, Jeana C. and Ye, Yanqi and Ball, Carmin and Williams, Alyssa and Chang, Xinyuan and Chen, Guojun and Gu, Zhen and Ristaino, Jean B. and et al.}, year={2019}, month={Jun}, pages={6540–6549} }