• The Plant Pathology Journal
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• v.38 no.2
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• pp.167-174
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• 2022

Pseudomonas amygdali is a hemibiotrophic phytopathogen that causes disease in woody and herbaceous plants. Complete genomes of four P. amygdali pathovars were comparatively analyzed to decipher the impact of genomic diversity on host colonization. The pan-genome indicated that 3,928 core genes are conserved among pathovars, while 504-1,009 are unique to specific pathovars. The unique genome contained many mobile elements and exhibited a functional distribution different from the core genome. Genes involved in O-antigen biosynthesis and antimicrobial peptide resistance were significantly enriched for adaptation to hostile environments. While the type III secretion system was distributed in the core genome, unique genomes revealed a different organization of secretion systems as follows: type I in pv. tabaci, type II in pv. japonicus, type IV in pv. morsprunorum, and type VI in pv. lachrymans. These findings provide genetic insight into the dynamic interactions of the bacteria with plant hosts.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.186-186
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• 2022

Phytophthora root and stem rot (PRSR) and wildfire disease (WFD) of soybean are frequently observed in the field of South Korea. The most environmentally friendly way to control PRSR and WFD is to use soybean varieties with resistance to Phytophthora sojae (P. sojae) and Pseudomonas amygdali pv. tabaci. Plant germplasm is an important gene pool for soybean breeding and improvement. In this study, hundreds of soybean accessions were evaluated for the two pathogens, and genome-wide association analyses were conducted using 104,955 SNPs to identify resistance loci for the two pathogens. Of 193 accessions, 46 genotypes showed resistance reaction, while 143 did susceptibility for PRSP. Twenty SNPs were significantly associated with resistance to P. sojae on chromosomes (Chr.) 3 and 4. Significant SNPs on Chr.3 were located within the known Rps gene region. A region on Chr. 4 is considered as a new candidate resistance loci. For evalation of resistance to WFD, 18, 31,74,36 and 34 genotypes were counted by a scale of 1-5, respectively. Five SNP markers on Chrs 9,11,12,17 and 18 were significantly associated with resistance to P. amygdali pv. tabaci. The identified SNPs and genomic regions will provide a useful information for further researches and breeding for resistance to P. sojae and P. amygdali pv. tabaci.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.11a
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• pp.125-125
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• 2020

• Research in Plant Disease
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• v.22 no.1
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• pp.38-43
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• 2016

Wildfire caused by Pseudomonas amygdali pv. tabaci has been seen a steady increase in the incidence and prevalence on soybean in Korea. But up to know there is no official report on the prevalence of the disease in Korea. The nationwide survey of the occurrence of soybean wildfire showed that 19 out of 30 regions in 2014 and 9 out of 28 regions in 2015 had been infected with P. amygdali pv. tabaci. The severity of wildfire varied according to the cultivar, cultivation regions and climates. However, cultivar seoeitae was susceptible in both 2014 and 2015. The disease severity of 2014 was twice that of 2015. Since the temperature of 2014 and 2015 were very similar but the precipitation of 2014 was more than twice that of 2015, the precipitation of 2014 had a great impact on the wildfire disease severity.