• Title/Summary/Keyword: Xanthomonas

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Aerial Distribution of Bacterial Groups of Xanthomonas oryzae (Uyeda et Ishiyama) Dowson in Korea (벼 흰빛잎마름병균의 균군의 분포에 관한 연구)

  • Choi Yong Chull;Lee Soon Gu;Chung Bong Jo;Cho Yong Sup
    • Korean journal of applied entomology
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    • v.18 no.1 s.38
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    • pp.23-27
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    • 1979
  • Studies on bacterial groups of X. oryzae in Korea has been continued annually since 1975. The present report maintained the result of recent Studies covering on 224 isolates collected front 191 portions of all over the country during the period from 1977 to 1978. The four bacterial groups, I, II, III and V, were found with the ratio of 79, 16, 3 and 3 per-cent, respectively. Variable bacterial groups were found in Chung- nam province while in Jeon- nam province the group II was more pre4valent than group I. Variety-group 'Kimmaze' maintained much more of heterogeneous bacterial groups, and it was significant, especially, on cultivar Milyang $\#23$. Variety-group 'Kogyoku' maintained group II, only while it was possible to isolate group I, II, and III from variety group 'Rantai-emas.' Isolates from Kresek symptom, mostly on Milyang $\#23$, belonged to group I and group II, and their occurring incidence were 20 and 8 out of 28 isolates, respectively. Variability of bacterial group was differed with the location of fields. There were homogeneous and heterogeneous groups, respectively, regardless of host varieties in a given locations.

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Aspect of Incidence of the Major Citrus Diseases Recently (최근 주요 감귤 병의 발생 양상)

  • Hyun, Jae-Wook;Yi, Pyoung-Ho;Hwang, Rok-Yeon;Moon, Kyung-Hwan
    • Research in Plant Disease
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    • v.19 no.2
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    • pp.102-107
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    • 2013
  • The percent of diseased fruit by Diaporthe citri was the most 16.8% in 2010 and the least 3.8% in 2005, and the average was 8.8% from 2003 to 2012. The degrees of disease incidence were relatively high, 17.0, 22.6, 19.2 and 18.9%, in 2003, 2004, 2007 and 2010, respectively. The percent of diseased fruit by Elsinoe fawcettii was the most 0.72% in 2004, and then gradually decreased to 0.08% in 2008, and the average was from 0.28% from 2004 to 2011. In case of canker by Xanthomonas citri subsp. citri, the percent of diseased fruit was the most 2.19% in 2004, and gradually decreased to 0.08 and 0.10% in 2009 and 2010, respectively. The average was 0.81% from 2004 to 2012. The melanose by D. citri was most in south-east area of Jeju Island, and east and west in case of canker. The melanose symptoms were initially appeared from mid June, mainly peaked late of July to late August. The canker symptoms were initially produced on leaves of natsudaidai and grapefruit cultivated in open field middle of June in 2010 and 2011 and late of May in 2012. The scab disease was firstly appeared approx. early or mid May and then rapidly increased late of May to middle of June. The inoculum was mainly produced from dead twigs late June to early of August.

Evaluation of Disease Resistance of a Leaffolder-resistant (Cry1Ac1) Rice Event and Gene Transfer to Plant Pathogens (혹명나방 저항성벼(Cry1Ac1)의 병해 저항성 및 병원균으로의 유전자 전이)

  • Nam, Hyo-Song;Shim, Hong-Sik;Yu, Sang-Mi;Lee, Se-Won;Kwon, Soon-Jong;Kim, Myung-Kon;Lee, Yong-Hoon
    • Research in Plant Disease
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    • v.15 no.3
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    • pp.202-208
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    • 2009
  • The genetically modified leaffolder-resistant (Cry1Ac1) rice plant was evaluated for the changes of resistance by comparing the occurrence of major diseases with a japonica type Korean rice variety, Nakdong which was the mother plant of the transgenic rice event, in greenhouse and field conditions. There was no difference in the occurrence of sheath blight and Helminthosporium blight between the two varieties in the fields. We couldn't find any difference of resistance for fungal blast and bacterial leaf blight by artificial inoculation in greenhouse. There was also no difference in the susceptibility to sheath blight in artificial inoculation tests confirming the results in the fields. The possibility of gene transfer of Bar and Cry1Ac1 from the genetically modified rice plant to naturally infected pathogens such as Fusarium moniliforme and Pyricularia oryzae in the field conditions was tested by PCR. And the possible transfer of those genes by continuous inoculation of Xanthomonas oryzae pv. oryzae and Rhizoctonia solani was also tested. However, we couldn't find any possibility of transfer of the genes in natural and artificial conditions.

Bacillus oryzicola sp. nov., an Endophytic Bacterium Isolated from the Roots of Rice with Antimicrobial, Plant Growth Promoting, and Systemic Resistance Inducing Activities in Rice

  • Chung, Eu Jin;Hossain, Mohammad Tofajjal;Khan, Ajmal;Kim, Kyung Hyun;Jeon, Che Ok;Chung, Young Ryun
    • The Plant Pathology Journal
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    • v.31 no.2
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    • pp.152-164
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    • 2015
  • Biological control of major rice diseases has been attempted in several rice-growing countries in Asia during the last few decades and its application using antagonistic bacteria has proved to be somewhat successful for controlling various fungal diseases in field trials. Two novel endophytic Bacillus species, designated strains YC7007 and $YC7010^T$, with antimicrobial, plant growth-promoting, and systemic resistance-inducing activities were isolated from the roots of rice in paddy fields at Jinju, Korea, and their multifunctional activities were analyzed. Strain YC7007 inhibited mycelial growth of major rice fungal pathogens strongly in vitro. Bacterial blight and panicle blight caused by Xanthomonas oryzae pv. oryzae (KACC 10208) and Burkholderia glumae (KACC 44022), respectively, were also suppressed effectively by drenching a bacterial suspension ($10^7cfu/ml$) of strain YC7007 on the rhizosphere of rice. Additionally, strain YC7007 promoted the growth of rice seedlings with higher germination rates and more tillers than the untreated control. The taxonomic position of the strains was also investigated. Phylogenetic analyses based on 16S rRNA gene sequences indicated that both strains belong to the genus Bacillus, with high similarity to the closely related strains, Bacillus siamensis KACC $15859^T$ (99.67%), Bacillus methylotrophicus KACC $13105^T$ (99.65%), Bacillus amyloliquefaciens subsp. plantarum KACC $17177^T$ (99.60%), and Bacillus tequilensis KACC $15944^T$ (99.45%). The DNA-DNA relatedness value between strain $YC7010^T$ and the most closely related strain, B. siamensis KACC $15859^T$ was $50.4{\pm}3.5%$, but it was $91.5{\pm}11.0%$ between two strains YC7007 and $YC7010^T$, indicating the same species. The major fatty acids of two strains were anteiso-$C_{15:0}$ and iso $C_{15:0}$. Both strains contained MK-7 as a major respiratory quinone system. The G+C contents of the genomic DNA of two strains were 50.5 mol% and 51.2 mol%, respectively. Based on these polyphasic studies, the two strains YC7007 and $YC7010^T$ represent novel species of the genus Bacillus, for which the name Bacillus oryzicola sp. nov. is proposed. The type strain is $YC7010^T$ (= KACC $18228^T$). Taken together, our findings suggest that novel endophytic Bacillus strains can be used for the biological control of rice diseases.

Breeding of a New Japanese Apricot (Prunus mume Siebold et Zucc.) Cultivar 'Okjoo' with High Yields (다수성 매실 품종 '옥주')

  • Kim, Yoon-Kyeong;Kang, Sam-Seok;Choi, Jang-Jeon;Cho, Kwang-Sik;Won, Kyeong-Ho;Lee, Han-Chan;Choi, Jin-Ho
    • Horticultural Science & Technology
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    • v.32 no.6
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    • pp.912-916
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    • 2014
  • Japanese apricot (Prunus mume Siebold and Zucc.) is a deciduous tree of the family Rosaceae, and it has long been used as a folk remedy for cough and dyspepsia. A new cultivar 'Okjoo' was developed from a cross between 'Gyokuei' and 'Rinsyu' carried out at the National Institute of Horticultural & Herbal Science in 1993. It w as s elected for good shape, large size and high yield capacity in 2006, and then it was granted official patent No. 4556 in 2013. It blooms 4 days and 2 days earlier than 'Gyokuei' and 'Rinsyu', respectively. Its flower petal color is pink, and the pollen amount is negligible. Its S-genotype, determined using Polymerase Chain Reaction with a S-RNase gene-specific primer pair, is $S_3S_6$. The average optimum harvest time of 'Okjoo' is late June. The fruit is round in shape and its suture is shallow. Average fruit weight is 18.5 g, and it contains total soluble solids $7.66^{\circ}Brix$ and titratable acidity at 4.81%. Fruit skin color is green. Sometimes only the light side of the fruits seems to develop blush. The incidence levels of scab (Cladosporium carpophilum Thumen) and bacterial shot hole (Xanthomonas arboricola pv. Pruni) are quite low. Consequently, 'Okjoo' seems to be a promising new cultivar for Japanese apricot growers.

Bactericidal Effects of Nano-silver Liquid Against Various Plant Pathogenic Bacteria (은 나노 용액의 식물병원성 세균에 대한 살균활성)

  • Kim, Sang-Woo;Min, Ji-Seon;Lee, Youn-Su
    • Research in Plant Disease
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    • v.15 no.2
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    • pp.130-133
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    • 2009
  • We have conducted in vitro experiments with nano-silver liquid for their effect against various plant pathogenic bacteria. Different types of nano-silver liquid WA-CV-WA13B, WA-AT-WB13R and WA-PR-WB13R were used. These are classified based on different manufacturing processes. The tested bacteria were provided by KACC. We experimented ten bacterial isolates in Clavibacter, Erwinia, Pseudomonas, Ralstonia, and Xanthomonas genera. In order to determine the level of concentrations of control effects, different concentrations (10, 25, 50, and 100 ppm) of each different nano-silver liquid were added in the culture media. As a result, WA-CV-WA13B showed high inhibition effect against C-1 at 10 ppm, and showed minor inhibition effects against P-6, X-1, and X-2. WA-AT-WB13R showed bactericidal effect against P-6 at 10 ppm. At 10 ppm, WA-AT-WB13R showed relatively high inhibition effects against C-1, X-1, and X-2. WA-PR-WB13R showed bactericidal effects against P-5, P-6 and X-2 at 10 ppm or higher concentrations. All the tested three nano-silver liquid showed bactericidal effects against all the tested plant pathogenic bacteria at concentrations of 25 ppm or higher. These results indicated the possible use of nano-silver liquid for the control of plant pathogenic bacteria.

Genetic Analysis on the Bacterial Blight Resistance Gene from a Wild Relative, Oryza minuta (야생벼 Oryza minuta에서 유래한 수원506호의 흰잎마름병 저항성유전자에 대한 고찰)

  • Jeung, Ji-Ung;Roh, Tae-Hwan;Kang, Kyung-Ho;Shin, Young-Seop;Kim, Yeon-Gyu
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.2
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    • pp.124-133
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    • 2011
  • Bacterial blight (BB), cuased by the vascular pathogen Xanthomonas oryzae pv. oryzae, is one of the major threats in rice fields worldwide. In Korea, two resistance genes against BB, Xa1 and Xa3 had been intensively used for developing high quality japonica rice cultivars. Those traditional resistance sources have being rapidly ified by the adopting of BB pathogen through mutations of the corresponding avr-genes, such as K3a exhibiting high compatibility to both Xa1 and Xa3. To expanding genetic resource against BB in Korea, the Suweon506, an introgression line between a Korean japonica cultivar, Hwaseong and a wild relative, Oryza minuta, was be subjected for genetic analysis owing to the BB resistance. Through association analyses between the pathotyping and genotyping results for each $F_2$ progenies, derived from a cross between Suweon506 and a Tongil type cultivar, Milyang23, a major resistant dominant gene is localized on the subterminal region of rice chromosome 4, where at least three BB resistancde genes, Xa1, Xa2, and Xa22, were reported previously.

A New Japanese Apricot (Prunus mume) Cultivar, "Okboseok" for High Yield (다수확 매실 신품종 "옥보석")

  • Jeong, Sang-Bouk;Kim, Yoon-Kyeong;Kang, Sam-Seok;Cho, Kwang-Sik;Choi, Jang-jeon
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.534-538
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    • 2009
  • Japanese apricot (Prunus mume) "Okboseok" was released from a cross between "Nanko" and "Yoseibai" in 1993 at the Pear Research Station of National Institute of Horticultural and Herbal Science, Rural Development Administration. It was preliminarily selected in 2001 and named in 2006. It produces high yield with a flesh about average 88.3% of fruit, although the fruit size is small (approximately 14.0g). Horticultural and physiological harvest time of this cultivar is mid and late June respectively. It has single flowers with pink petal color and its flowering time is about 4 days later than that of "Nanko". Its fruit is tolerant to bacterial shot hole (Xanthomonas arboricola pv. Pruni) and pear scab (Venturia nashicola). "Okboseok" has abundant pollen grains (about 96 mg/100 flowers), thus it could be a pollinizer. To obtain stable yields, however, its compatibility with major cultivars is needed to be confirmed as pollinizer cultivar. "Okboseok" is recommended for being preserved in sugar and liquor.

Screening of Bacterial Strains for Alleviating Drought Stress in Chili Pepper Plants (고추 식물의 건조 스트레스 완화를 위한 미생물 선발)

  • Kim, Sang Tae;Yoo, Sung-Je;Song, Jaekyeong;Weon, Hang-Yeon;Sang, Mee Kyung
    • Research in Plant Disease
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    • v.25 no.3
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    • pp.136-142
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    • 2019
  • Drought stress is considered as one of major abiotic stresses; it leads to reduce plant growth and crop productivity. In this study, we selected bacterial strains for alleviating drought stress in chili pepper plants. As drought-tolerant bacteria, 28 among 447 strains were pre-selected by in vitro assays including growth in drought condition with polyethylene glycol and plant growth-promoting traits including production of 1-aminocyclopropane-1-carboxylate deaminase, indole-3-acetic acid and exopolysaccharide. Sequentially, 7 among pre-selected 28 strains were screened based on relative water content (RWC); GLC02 and KJ40, among seven strains were finally selected by RWC and malondialdehyde (MDA) in planta trials under an artificial drought condition by polyethylene glycol solution. Two strains GLC02 and KJ40 reduced drought stress in a natural drought condition as well as an artificial condition. Strains GLC02 or KJ40 increased shoot fresh weight, chlorophyll and stomatal conductance while they decreased MDA in chili pepper plants under a natural drought condition. However, two strains did not show biocontrol activity against diseases caused by Phytophthora capsici and Xanthomonas campestris pv. vesicatoria in chili pepper plants. Taken together, strains GLC02 or KJ40 can be used as bio-fertilizer for alleviation of drought stress in chili pepper plants.

Fine mapping of rice bacterial leaf blight resistance loci on K1 and K2 of Korean races of Xoo (Xanthomonas oryzae) using GWAS analysis

  • Hyeon, Do-Yun;Lee, Jeong-Ro;Jo, Gyu-Taek;Raveendar, Sebastin;Sin, Myeong-Jae;Lee, Gyeong-Jun
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.04a
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    • pp.62-62
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    • 2019
  • Bacterial leaf blight(BLB), caused by X. oryzae pv. oryzae(Xoo), is one of the most destructive diseases of rice due to its high epidemic potential. Understanding BLB resistance at a genetic level is important to further improve the rice breeding that provides one of the best approaches to control BLB disease. In the present investigation, a collection of 192 accessions was used in the genome-wide association study (GWAS) for BLB resistance loci against four Korean races of Xoo that were represented by the prevailing BLB isolates under Xoo differential system. A total of 192 accessions of rice germplasm were selected on the basis of the bioassay using four isolated races of Xoo such as K1 and K2. The selected accessions was used to prepare 384-plex genotyping by sequencing (GBS) libraries and Illumina HiSeq 2000 pairedend read was used for GBS sequencing. GWAS was conducted using TASSEL 5.0. The TASSEL program uses a mixed linear model (MLM). The results of the bioassay using a selected set of 192 accessions showed that a large number of accessions (93.75%) were resistant to K1 race and K2 resistant germplasm proportion remained between 66.67. The genotypic data produced SNP matrix for a total of 293,379 SNPs. After imputation the missing data was removed, which exhibited 34,724 SNPs for association analysis. GWAS results showed strong signals of association at a threshold of [-log10(P-value)] more than 5 (K1 and K2) for nine of the 39 SNPs, which are plausible candidate loci of resistance genes. These SNP loci were positioned on rice chromosome 2, 9, and 11 for K1 and K2 races. The significant loci detected have also been illustrated and make the CPAS markers for NBS-LRR type disease resistance protein, SNARE domain containing protein, Histone deacetylase 19, NADP-dependent oxidoreductase, and other expressed and unknown proteins. Our results provide a better understanding of the distribution of genetic variation of BLB resistance to Korean pathogen races and breeding of resistant rice.

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