scholarly journals Genetic Diversity and Population Structure of the Xanthomonas campestris pv. campestris Strains Affecting Cabbages in China Revealed by MLST and Rep-PCR Based Genotyping

2021 ◽  
Vol 37 (5) ◽  
pp. 476-488
Author(s):  
Guo Chen ◽  
Congcong Kong ◽  
Limei Yang ◽  
Mu Zhuang ◽  
Yangyong Zhang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Xanthomonas Campestris ◽  
Resistance Breeding ◽  
Black Rot ◽  
Yield Losses ◽  
Mlst Analysis ◽  
Pathogen Diversity ◽  
Pathogenicity Tests ◽  
Xanthomonas Campestris Pv Campestris

<i>Xanthomonas campestris</i> pv. <i>campestris</i> (<i>Xcc</i>) is the causal agent of black rot for cruciferous vegetables worldwide, especially for the cole crops such as cabbage and cauliflower. Due to the lack of resistant cabbage cultivars, black rot has brought about considerable yield losses in recent years in China. Understanding of the pathogen features is a key step for disease prevention, however, the pathogen diversity, population structure, and virulence are largely unknown. In this study, we studied 50 <i>Xcc</i> strains including 39 <i>Xcc</i> isolates collected from cabbage in 20 regions across China, using multilocus sequence genotyping (MLST), repetitive DNA sequence-based PCR (rep-PCR), and pathogenicity tests. For MLST analysis, a total of 12 allelic profiles (AP) were generated, among which the largest AP was AP1 containing 32 strains. Further cluster analysis of rep-PCR divided all strains into 14 DNA groups, with the largest group DNA I comprising of 34 strains, most of which also belonged to AP1. Inoculation tests showed that the representative <i>Xcc</i> strains collected from diverse regions performed differential virulence against three brassica hosts compared with races 1 and 4. Interestingly, these results indicated that AP1/DNA I was not only the main pathotype in China, but also a novel group that differed from the previously reported type races in both genotype and virulence. To our knowledge, this is the first extensive genetic diversity survey for <i>Xcc</i> strains in China, which provides evidence for cabbage resistance breeding and opens the gate for further cabbage-<i>Xcc</i> interaction studies.

Construction of a Linkage Map and QTL analysis for Black Rot Resistance in Brassica oleracea L.

1970 ◽  
Vol 1 (1) ◽  
pp. 1-6 ◽  
Author(s):  
MAU Doullah ◽  
GM Mohsin ◽  
K Ishikawa ◽  
H Hori ◽  
K Okazaki
Keyword(s):  
Linkage Map ◽  
Brassica Oleracea ◽  
Phenotypic Variation ◽  
Xanthomonas Campestris ◽  
Resistance Breeding ◽  
Black Rot ◽  
Significant Qtls ◽  
Disease Rating ◽  
Genomic Regions ◽  
Xanthomonas Campestris Pv Campestris

For quantitative trait loci (QTL) controlling resistance to Xanthomonas campestris pv. Campestris, we constructed linkage map using cleaved amplified plymorphic sequences (CAPS) and sequence-related amplified polymorphism (SRAP) analysis with disease rating of F3 families obtained from a susceptible broccoli and resistant cabbage [Green commet P09 × Reiho P01]. We established inoculation technique. In this technique, leaves from approximately 50-day old F3 plants were inoculated by cutting 1.0 cm at mid vain near the margins. A total of 38 CAPS and 60 SRAP primer pairs were screened to assess parental polymorphism against black rot resistance. Ninety two markers were distributed in 10 linkage groups (LGs) covering 320.5 cM (centimorgan), with average 3.56 cM interval between markers. Two genomic regions on LG 2 and LG 9 were significantly associated with resistance to the disease. The analysis revealed QTLs in the map interval between CAM1 – GSA1 on LG 2 accounting for up to 10% of the phenotypic variation and one QTL in the map interval between F12-R12e – BORED on LG 9 explaining 16% phenotypic variation with LOD score of 3.09. Two additional non-significant QTLs on LG 3 in the interval between CHI – ASB1 (LOD = 2.04) and on LG 7 in the interval between IPI – FLC3 (LOD = 2.25) were also detected for resistance to the disease. The QTLs, which were mapped to LG 2 and LG 9 for the disease, could be useful for marker-assisted selection in resistance breeding. Key words: Linkage map; QTL; Black rot; Resistance; Brassica oleracea  DOI: http://dx.doi.org/10.3329/ijns.v1i1.8591 International Journal of Natural Sciences (2011), 1(1):1-6

scholarly journals Recent Outbreaks of Black Rot of Brassicas Caused by Xanthomonas campestris pv. campestris in Southern Mozambique

Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1218-1218
Author(s):  
J. Bila ◽  
A. M. Mondjana ◽  
E. G. Wulff ◽  
C. N. Mortensen
Keyword(s):  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Identification System ◽  
Black Rot ◽  
Microbial Identification ◽  
Brassica Spp ◽  
Brassica Crop ◽  
Leaf Tissues ◽  
Pathogenicity Tests ◽  
Xanthomonas Campestris Pv Campestris

In August and September of 2007, black rot symptoms were observed on seedbed and field plants of Brassica spp. grown in the southern districts of Boane, Mahotas, and Chòkwé in Mozambique. One hundred eighty-two cabbage-growing households were evaluated for the incidence of Xanthomonas campestris pv. campestris. Five Brassica cultivars, Glory F1, Glory of Enkhuizen, Copenhagen Market, Starke (Brassica oleracea pv. capitata L.), and Tronchuda (B. oleracea L. var. costata DC) were grown in the areas for several years. The hybrid Glory F1 was the most popular grown cultivar in the surveyed areas. In the Boane district, the highest incidence of black rot was recorded on Copenhagen Market (70%), Starke (67.9%), and Glory F1 (67.3%). In Chòkwé, Tronchuda (Portuguese kale) was the least affected Brassica crop. Water-soaked lesions starting at the edge of leaves with typical V-shaped necrotic lesions and vein discoloration were the most commonly observed symptoms. When examined with a microscope, cut edges of symptomatic stem and leaf tissues consistently exhibited bacterial streaming. The bacteria were isolated from commercial seed and field-grown plants on semiselective agar media (2). Forty-six X. campestris pv. campestris strains that were gram negative, aerobic, starch positive, nitrate negative, and oxidase negative or weakly positive (3) were further identified on the basis of ELISA (Agdia Inc., Elhart, IN), GN Biolog Microbial Identification System, version 4.2 (Biolog Inc., Hayward, CA), and PCR-specific primers (1). Pathogenicity tests were conducted by pin inoculating two upper leaves of cabbage (cv. Wirosa) in the 2- to 3-leaf stage with bacterial growth from 24-h-old agar cultures (2). Black rot symptoms developed on nearly all inoculated plants within 7 to 14 days. No symptoms were observed on control plants inoculated with a sterile pin without bacterial inoculum. The severity of black rot of Brassica spp. in three important farming districts caused significant losses in Mozambique. References: (1) T. Berg et al. Plant Pathol. 54:416, 2005. (2) S. J. Roberts and H. Koenraadt. Page 1 in: International Rules for Seed Testing: Annexe to Chapter 7 Seed Health Methods. ISTA, 2007. (3) N. W. Schaad et al. Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. The American Phytopathological Society, St. Paul, MN, 2001.

scholarly journals Genomic insights advance the fight against black rot of crucifers

2021 ◽  
Vol 87 (3) ◽  
pp. 127-136
Author(s):  
Zoë E. Dubrow ◽  
Adam J. Bogdanove
Keyword(s):  
Virulence Factors ◽  
Xanthomonas Campestris ◽  
Plant Pathogens ◽  
Impact Resistance ◽  
Resistance Breeding ◽  
Genetic Data ◽  
Black Rot ◽  
Inoculum Sources ◽  
New Knowledge ◽  
The World

AbstractXanthomonas campestris pv. campestris, the causal agent of black rot of crucifers, was one of the first bacterial plant pathogens ever identified. Over 130 years later, black rot remains a threat to cabbage, cauliflower, and other Brassica crops around the world. Recent genomic and genetic data are informing our understanding of X. campestris taxonomy, dissemination, inoculum sources, and virulence factors. This new knowledge promises to positively impact resistance breeding of Brassica varieties and management of inoculum sources.

Improved control of black rot of broccoli caused by Xanthomonas campestris pv. campestris using a bacteriophage and a nonpathogenic Xanthomonas sp. strain

2017 ◽  
Vol 83 (6) ◽  
pp. 373-381 ◽  
Author(s):  
Hirofumi Nagai ◽  
Noriyuki Miyake ◽  
Shinro Kato ◽  
Daisuke Maekawa ◽  
Yasuhiro Inoue ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Black Rot ◽  
Xanthomonas Campestris Pv Campestris

scholarly journals Antagonism of yeasts to Xanthomonas campestris pv. campestris on cabbage phylloplane in field

1999 ◽  
Vol 30 (3) ◽  
pp. 191-195 ◽  
Author(s):  
Sayonara M.P. Assis ◽  
Rosa L.R. Mariano ◽  
Sami J. Michereff ◽  
Gil Silva ◽  
Elizabeth A.A. Maranhão
Keyword(s):  
Disease Severity ◽  
Xanthomonas Campestris ◽  
Antagonistic Activity ◽  
Black Rot ◽  
Significant Difference ◽  
Xanthomonas Campestris Pv Campestris

Twenty yeast isolates, obtained from cabbage phylloplane, were evaluated for antagonistic activity against Xanthomonas campestris pv. campestris, in field. Plants of cabbage cv. Midori were pulverized simultaneously with suspensions of antagonists and pathogen. After 10 days, plants were evaluated through percentage of foliar area with lesions. Percentage of disease severity reduction (DSR%) was also calculated. Yeast isolates LR32, LR42 and LR19 showed, respectively, 72, 75 and 79% of DSR. These antagonists were tested in seven different application periods in relation to pathogen inoculation (T1=4 d before; T2=simultaneously; T3=4 d after; T4=4 d before + simultaneously; T5=4 d after + simultaneously; T6=4 d before + 4 d after; T7=4 d before + simultaneously + 4 d after). The highest DSRs were showed by LR42 (71%), LR42 (67%), LR35 (69%) and LR19 (68%) in the treatments T7, T4, T5 and T6, which significantly differed from the others. The same yeast antagonists were also tested for black rot control using different cabbage cultivars (Fuyutoyo, Master-325, Matsukaze, Midori, Sekai I and Red Winner). The DSRs varied from 58 to 61%, and there was no significant difference among cultivars.

scholarly journals Identification of Black Rot Resistance in a Wild Brassica Species and Its Potential Transferability to Cauliflower

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1400
Author(s):  
Xiao-Guang Sheng ◽  
Ferdinando Branca ◽  
Zhen-Qing Zhao ◽  
Jian-Sheng Wang ◽  
Hui-Fang Yu ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Resistance Breeding ◽  
Brassica Species ◽  
Gene Location ◽  
F1 Hybrids ◽  
Black Rot ◽  
Resistant Parent ◽  
F2 Population ◽  
Related Wild Species ◽  
Wild Accessions

Black rot is a destructive disease that affects B. oleracea crops, causing significant losses to growers throughout the world. The purpose of this study was to screen out new sources resistant to Xanthomonas campestris pv. campestris race 4 (Xcc4) in 26 cauliflower and six related wild species, and to assess the inheritance of resistance. The results indicate that most of the tested accessions were susceptible or had intermediate resistance, except the Boc4601 (a cauliflower stable inbred line) and PI435896, UNICT5168, and UNICT5169 (wild accessions). Among them, UNICT5169 (Brassica montana) and PI435896 (Brassica balearica) showed the strongest resistance to Xcc4, with significantly lower disease index (DI), area of the infected part (AIP) and proportion of the infected part to the total leaf area (PTL) values. UNICT 5169 was selected as an Xcc4-resistant parent because of its relatively good cross seed-setting rate with cauliflower cultivars. F1 hybrids were successfully produced between this wild resistant accession (UNICT 5169) and one susceptible cauliflower breeding line (Boc3202-4), indicating the potential transferability of this resistance to cauliflower. The results of the symptoms severity evaluation of the F2 population indicate that Xcc4 resistance in UNICT5169 is a quantitative trait, which guides future resistance gene location and black rot resistance breeding.

scholarly journals Characterization of Xanthomonas campestris pv. campestris in Algeria

2021 ◽  
Vol 60 (1) ◽  
pp. 51-62
Author(s):  
Samia LAALA ◽  
Sophie CESBRON ◽  
Mohamed KERKOUD ◽  
Franco VALENTINI ◽  
Zouaoui BOUZNAD ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Housekeeping Genes ◽  
First Record ◽  
Black Rot ◽  
Physiological And Biochemical Characteristics ◽  
Main Production ◽  
Production Areas ◽  
Cruciferous Plants ◽  
Xanthomonas Campestris Pv Campestris

Xanthomonas campestris pv. campestris (Xcc) causes the black rot of cruciferous plants. This seed-borne bacterium is considered as the most destructive disease to cruciferous crops. Although sources of contamination are various, seeds are the main source of transmission. Typical symptoms of black rot were first observed in 2011 on cabbage and cauliflower fields in the main production areas of Algeria. Leaf samples displaying typical symptoms were collected during 2011 to 2014, and 170 strains were isolated from 45 commercial fields. Xcc isolates were very homogeneous in morphological, physiological and biochemical characteristics similar to reference strains, and gave positive pathogenicity and molecular test results (multiplex PCR with specific primers). This is the first record of Xcc in Algeria. Genetic diversity within the isolates was assessed in comparison with strains isolated elsewhere. A multilocus sequence analysis based on two housekeeping genes (gyrB and rpoD) was carried out on 77 strains representative isolates. The isolates grouped into 20 haplotypes defined with 68 polymorphic sites. The phylogenetic tree obtained showed that Xcc is in two groups, and all Algerian strains clustered in group 1 in three subgroups. No relationships were detected between haplotypes and the origins of the seed lots, the varieties of host cabbage, the years of isolation and agroclimatic regions.

Genetic diversity and population structure of the rice false smut pathogen Ustilaginoidea virens in Sichuan-Chongqing region

Plant Disease ◽  
2021 ◽  
Author(s):  
Anfei Fang ◽  
Zhuangyuan Fu ◽  
Zexiong Wang ◽  
Yuhang Fu ◽  
Yubao Qin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Recombination ◽  
Resistance Breeding ◽  
Ustilaginoidea Virens ◽  
Breeding Lines ◽  
Rice False Smut ◽  
Geographical Populations ◽  
False Smut

Rice false smut caused by Ustilaginoidea virens is currently one of the most devastating fungal diseases of rice panicles worldwide. In this study, two novel molecular markers derived from SNP-rich genomic DNA fragments and a previously reported molecular marker were used for analyzing the genetic diversity and population structure of 167 U. virens isolates collected from nine areas in Sichuan-Chongqing region, China. A total of 62 haplotypes were identified, and a few haplotypes with high frequency were found and distributed in two to three areas, suggesting gene flow among different geographical populations. All isolates were divided into six genetic groups. The groups Ⅰ and Ⅵ were the largest including 61 and 48 isolates, respectively. The pairwise FST values showed significant genetic differentiation among all compared geographical populations. AMOVA showed that intergroup genetic variation accounted for 40.17% of the total genetic variation, while 59.83% of genetic variation came from intragroup. The UPGMA dendrogram and population structure revealed that the genetic composition of isolates collected from ST (Santai), NC (Nanchong), YC (Yongchuan), and WS (Wansheng) dominated by the same genetic subgroup was different from those collected from other areas. In addition, genetic recombination was found in a few isolates. These findings will help to improve the strategies for rice false smut management and resistance breeding, such as evaluating breeding lines with different isolates or haplotypes at different elevations and landforms.

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