scholarly journals First Report in Mali of Xanthomonas citri pv. mangiferaeindicae Causing Mango Bacterial Canker on Mangifera indica

Plant Disease ◽  
2012 ◽  
Vol 96 (4) ◽  
pp. 581-581 ◽  
Author(s):  
O. Pruvost ◽  
C. Boyer ◽  
K. Vital ◽  
C. Verniere ◽  
L. Gagnevin ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Mangifera Indica ◽  
Negative Control ◽  
Tris Buffer ◽  
Control Treatment ◽  
Bacterial Canker ◽  
Xanthomonas Citri ◽  
First Report ◽  
Infection Pattern ◽  
Wide Range

Bacterial canker (or black spot) of mango caused by Xanthomonas citri pv. mangiferaeindicae is an important disease in tropical and subtropical areas (1). X. citri pv. mangiferaeindicae can cause severe infection in a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Severe leaf infection may result in abscission. Fruit symptoms appear as small, water-soaked spots on the lenticels that later become star shaped, erumpent, and exude an infectious gum. Often, a “tear stain” infection pattern is observed on the fruit. Severe fruit infections cause premature drop. Twig cankers are potential sources of inoculum and weaken branch resistance to winds. Yield loss up to 85% has been reported at grove scale for susceptible cultivars (1). Suspected leaf lesions of bacterial canker were collected in July 2010 from mango trees in four, six, and three localities of the Koulikoro, Sikasso, and Bougouni provinces of Mali, respectively (i.e., the major mango-growing areas in this country). Nonpigmented Xanthomonas-like colonies were isolated on KC semiselective medium (3). Twenty-two strains from Mali were identified as X. citri pv. mangiferaeindicae based on IS1595-ligation-mediated PCR (4) and they produced fingerprints fully identical to that of strains isolated from Ghana and Burkina Faso. Five Malian strains (LH409, LH410, LH414, LH415-3, and LH418) were compared by multilocus sequence analysis (MLSA) to the type strain of X. citri and the pathotype strain of several X. citri pathovars, including pvs. anacardii and mangiferaeindicae. This assay targeted the atpD, dnaK, efp, and gyrB genes, as described previously (2). Nucleotide sequences were 100% identical to those of the pathotype strain of X. citri pv. mangiferaeindicae whatever the gene assayed, but differed from any other assayed X. citri pathovar. Leaves of mango cv. Maison Rouge from the youngest vegetative flush were infiltrated (10 inoculation sites per leaf for three replicate leaves on different plants per bacterial strain) with the same five strains from Mali. Bacterial suspensions (~1 × 105 CFU/ml) were prepared in 10 mM Tris buffer (pH 7.2) from 16-h-old cultures on YPGA (7 g of yeast, 7 g of peptone, 7 g of glucose, and 18 g of agar/liter, pH 7.2). The negative control treatment consisted of three leaves infiltrated with sterile Tris buffer (10 sites per leaf). Plants were incubated in a growth chamber at 30 ± 1°C by day and 26 ± 1°C by night (12-h/12-h day/night cycle) at 80 ± 5% relative humidity. All leaves inoculated with the Malian strains showed typical symptoms of bacterial canker a week after inoculation. No lesions were recorded from the negative controls. One month after inoculation, mean X. citri pv. mangiferaeindicae population sizes ranging from 5 × 106 to 1 × 107 CFU/lesion were recovered from leaf lesions, typical of a compatible interaction (1). To our knowledge, this is the first report of the disease in Mali. Investigations from local growers suggest that the disease may have been present for some years in Mali but likely less than a decade. A high disease incidence and severity were observed, suggesting the suitability of environmental conditions in this region for the development of mango bacterial canker. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (4) O. Pruvost et al. Phytopathology 101:887, 2011.

scholarly journals First Report of Xanthomonas citri pv. mangiferaeindicae Causing Mango Bacterial Canker on Mangifera indica in Ivory Coast

Plant Disease ◽  
2014 ◽  
Vol 98 (12) ◽  
pp. 1740-1740 ◽  
Author(s):  
O. Pruvost ◽  
C. Boyer ◽  
P. Grygiel ◽  
K. Boyer ◽  
C. Verniere ◽  
...  
Keyword(s):  
Ivory Coast ◽  
Disease Incidence ◽  
Mangifera Indica ◽  
Negative Control ◽  
Tris Buffer ◽  
Control Treatment ◽  
Bacterial Canker ◽  
Xanthomonas Citri ◽  
First Report ◽  
Wide Range

Xanthomonas citri pv. mangiferaeindicae causing bacterial canker (or black spot) is a major mango (Mangifera indica L.) pathogen in tropical and subtropical areas (3). The bacterium infects a wide range of mango cultivars, and induces raised, angular, black leaf lesions, sometimes with a yellow chlorotic halo. Fruit symptoms first appear as small water-soaked spots on the lenticels turning into star-shaped, erumpent lesions, which exude an infectious gum, yielding tear-stain patterns. Severe infections cause severe defoliation and/or premature fruit drop. Twig cankers are potential sources of inoculum and weaken branch resistance to winds. Drastic yield losses have been reported at grove scale for susceptible cultivars (3). Mango leaves showing typical angular, black, raised leaf lesions were first observed and collected in April 2014 from trees cv. Kent in five localities of the Korhogo province of Ivory Coast (i.e., the major commercial mango-growing area in this country). Non-pigmented Xanthomonas-like colonies were isolated on KC semi-selective medium (4). Five strains (LL60-1, LL61-1, LL62-1, LL63-1, and LL64-1), one from each locality, were compared by multilocus sequence analysis (MLSA) to the type strain of X. citri and the pathotype strain of several X. citri pathovars, including pvs. anacardii and mangiferaeindicae. This assay targeted the atpD, dnaK, efp, and gyrB genes, as described previously (2). Nucleotide sequences were 100% identical to those of the pathotype strain of X. citri pv. mangiferaeindicae whatever the gene assayed, but differed from any other assayed X. citri pathovar. Leaves of mango cv. Maison Rouge from the youngest vegetative flush were infiltrated (10 inoculation sites/leaf for three replicate leaves on different plants/bacterial strain) as detailed previously (1) with the same five strains. Bacterial suspensions (~1 × 105 cfu/ml) were prepared in 10 mM Tris buffer (pH 7.2) from 16-h-old cultures on YPGA (7 g yeast, 7 g peptone, 7 g glucose, and 18 g agar/liter, pH 7.2). The negative control treatment consisted of three leaves infiltrated with sterile Tris buffer (10 sites/leaf). Plants were incubated in a growth chamber at 30 ± 1°C by day and 26 ± 1°C by night (12-h day/night cycle) at 80 ± 5% RH. All leaves inoculated with the strains from Ivory Coast showed typical symptoms of bacterial canker a week after inoculation. No lesions were recorded from the negative controls. The pathogen was recovered at high population densities (>1 × 106 cfu/lesion) from leaf lesions, typical of a compatible interaction (1) and isolated colonies were identified as the target by atpD sequencing (2). Koch's postulates have therefore been fully verified. This is the first report of the disease in Ivory Coast, a country which has been an internationally significant mango exporter (up to 15,000 tons per year) over the last two decades. A high disease incidence and severity were observed, outlining the need for implementing integrated pest management in mango groves and the production of disease-free nursery stock. This report further expands the distribution of the pathogen in West Africa after its first description from Ghana in 2011 (5) and subsequently in other neighboring countries. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) L. Gagnevin and O. Pruvost. Plant Dis. 85:928, 2001. (4) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (5) O. Pruvost et al. Plant Dis. 95:774, 2011.

scholarly journals First Report in Ghana of Xanthomonas citri pv. mangiferaeindicae Causing Mango Bacterial Canker on Mangifera indica

Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 774-774 ◽  
Author(s):  
O. Pruvost ◽  
C. Boyer ◽  
K. Vital ◽  
C. Verniere ◽  
L. Gagnevin ◽  
...  
Keyword(s):  
Mangifera Indica ◽  
Black Spot ◽  
Severe Infection ◽  
Negative Control ◽  
Tris Buffer ◽  
Bacterial Canker ◽  
Xanthomonas Citri ◽  
First Report ◽  
Infection Pattern ◽  
Wide Range

Bacterial canker of mango (or bacterial black spot), caused by Xanthomonas citri pv. mangiferaeindicae, is an economically important disease in tropical and subtropical producing areas (1). X. citri pv. mangiferaeindicae can cause severe infection in a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Several months after infection, leaf lesions dry and turn light brown or ash gray. Severe leaf infection may result in abscission. Fruit symptoms appear as small water-soaked spots on the lenticels. These spots later become star shaped, erumpent, and exude an infectious gum. Often, a “tear stain” infection pattern is observed on the fruit. Severe fruit infections will cause premature fruit drop. Twig cankers are potential sources of inoculum and weaken resistance of branches to wind damage. Leaf lesions with suspected bacterial canker were collected in January 2010 from mango trees cv. Keitt in several blocks at the Integrated Tamale Fruit Company, Ghana. Non-pigmented Xanthomonas-like bacterial colonies were isolated on Kasugamycin-Cephalexin semiselective agar medium (3). On the basis of IS1595-Ligation Mediated-PCR data, 16 strains from Ghana produced identical fingerprints and were identified as X. citri pv. mangiferaeindicae (4). The haplotype corresponding to the Ghanaian strains had not been previously reported. On the basis of multidimensional scaling (4), this haplotype clustered together with a group of strains from multiple origins and the analysis was not informative as an aid for tracing back the outbreak. Five Ghanaian strains (LH2-3, LH2-6, LH2-8, LH2-11, and LH2-15) were compared by multilocus sequence analysis to the type strain of X. citri and the pathotype strain of several X. citri pathovars, including pvs. anacardii and mangiferaeindicae. This assay targeted the atpD, dnaK, efp, and gyrB genes as described previously (2). Nucleotide sequences were 100% identical to those of the pathotype strain of X. citri pv. mangiferaeindicae whatever the gene assayed, but differed from any other assayed X. citri pathovar. Mango cv. Maison Rouge leaves from the youngest vegetative flush were infiltrated (10 inoculation sites per leaf, three replicate plants) using inoculum of each of the same five Ghanaian strains made from suspensions in Tris buffer containing ~1 × 105 CFU/ml. Negative control treatments consisted of leaves infiltrated with sterile Tris buffer. Typical symptoms of bacterial canker were observed for all assayed strains a week after inoculation. No lesions were recorded from the negative control. One month after inoculation, mean X. citri pv. mangiferaeindicae population sizes ranging from 4 × 107 to 1 × 108 CFU/lesion were recovered from leaf lesions, typical of a compatible interaction (1). High disease prevalence was observed in Ghana, indicating the suitability of environmental conditions in this region for the development of mango bacterial canker. The budwood for these blocks was imported from Burkina Faso in 2002 and symptoms were observed in these blocks shortly after establishment. To our knowledge, this is the first report of mango bacterial canker in Western Africa. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (4) O. Pruvost et al. Phytopathology. Online publication. DOI:10.1094/PHYTO-11-10-0304, 2011.

scholarly journals First Report in Burkina Faso of Xanthomonas citri pv. mangiferaeindicae Causing Bacterial Canker on Mangifera indica

Plant Disease ◽  
2011 ◽  
Vol 95 (10) ◽  
pp. 1312-1312 ◽  
Author(s):  
O. Pruvost ◽  
C. Boyer ◽  
K. Vital ◽  
C. Verniere ◽  
L. Gagnevin ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Mangifera Indica ◽  
Severe Infection ◽  
Negative Control ◽  
Tris Buffer ◽  
Control Treatment ◽  
Bacterial Canker ◽  
Xanthomonas Citri ◽  
Wide Range ◽  
Severe Infections

Bacterial canker of mango (or bacterial black spot) caused by Xanthomonas citri pv. mangiferaeindicae, is an economically important disease in tropical and subtropical areas (1). X. citri pv. mangiferaeindicae can cause severe infection on a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Fruit symptoms are black, star shaped, erumpent, and exude an infectious gum. A survey was conducted in Burkina Faso in May 2010 because budwood putatively associated with an outbreak of bacterial canker in Ghana had originated from Burkina Faso (3). Leaves and twigs with suspected bacterial canker lesions were collected from mango trees of the cvs. Amélie, Brooks, and Kent and from seedlings at five localities in Comoe and Houet provinces. Severe infections were observed on the sampled trees in Burkina Faso and leaf symptoms were typical of bacterial canker. Leaves were surface sterilized for 15 to 30 s with 70% ethanol, and nonpigmented, Xanthomonas-like bacterial colonies were isolated on KC semiselective agar medium (1). On the basis of an IS1595-ligation mediated PCR assay, 18 strains from Burkina Faso produced identical fingerprints and were identified as X. citri pv. mangiferaeindicae (4). The haplotype for strains from Burkina Faso was identical to that reported from Ghana (3). Three strains from Burkina Faso (LH127-2, LH130-1, and LH131-1) were compared by multilocus sequence analysis (MLSA) with the type strain of X. citri and the pathotype strain of several X. citri pathovars, including pvs. anacardii and mangiferaeindicae, targeting the atpD, dnaK, efp, and gyrB genes (2). Nucleotide sequences were 100% identical to those of the pathotype strain of X. citri pv. mangiferaeindicae, regardless of the gene assayed, but differed from any other X. citri pathovar assayed. Leaves of mango cv. Maison Rouge, taken from the youngest vegetative flush, were infiltrated (10 inoculation sites per leaf for three replicate leaves on different plants per bacterial strain) with the same three strains from Burkina Faso. Bacterial suspensions (approximately 1 × 105 CFU/ml) were prepared in 10 mM Tris buffer (pH 7.2) from 16-h-old solid cultures on YPG agar (7 g of yeast, 7 g of peptone, 7 g of glucose, and 18 g of agar per liter, pH 7.2). The negative control treatment consisted of three leaves infiltrated with sterile Tris buffer (10 sites per leaf). Plants were incubated in a growth chamber at 30 ± 1°C by day and 26 ± 1°C by night (12-h/12-h day/night cycle) at 80 ± 5% relative humidity. Typical symptoms of bacterial canker were observed for all assayed strains 1 week after inoculation; no symptoms were observed from negative control leaves. One month after inoculation, mean X. citri pv. mangiferaeindicae populations ranging from 2 × 107 to 8 × 107 CFU/leaf lesion were recovered, which was typical of a compatible interaction (1). The origin of inoculum associated with the bacterial canker outbreak in Burkina Faso is unknown. This report documents severe infections in Burkina Faso (including premature fruit drop due to severe fruit infections) and confirms the presence of bacterial canker in western Africa. A more extensive survey for the disease should be conducted in this region. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) O. Pruvost et al. Plant Dis. 95:774, 2011. (4) O. Pruvost et al. Phytopathology 101:887, 2011.

scholarly journals First Report of Xanthomonas citri pv. mangiferaeindicae Causing Mango Bacterial Canker on Mangifera indica L. in Benin

Plant Disease ◽  
2015 ◽  
Vol 99 (12) ◽  
pp. 1854-1854 ◽  
Author(s):  
C. Zombré ◽  
P. Sankara ◽  
S. L. Ouédraogo ◽  
I. Wonni ◽  
O. Pruvost ◽  
...  
Keyword(s):  
Mangifera Indica ◽  
Bacterial Canker ◽  
Xanthomonas Citri ◽  
First Report

scholarly journals First Report of Xanthomonas citri pv. mangiferaeindicae Causing Mango Bacterial Canker on Mangifera indica in Togo

Plant Disease ◽  
2017 ◽  
Vol 101 (3) ◽  
pp. 503-503
Author(s):  
C. Zombré ◽  
I. Wonni ◽  
S. L. Ouédraogo ◽  
K. E. Kpemoua ◽  
K. Assignon ◽  
...  
Keyword(s):  
Mangifera Indica ◽  
Bacterial Canker ◽  
Xanthomonas Citri ◽  
First Report

scholarly journals First Report in Hawai'i of Xanthomonas citri pv. mangiferaeindicae Causing Bacterial Black Spot on Mangifera indica

Plant Disease ◽  
2013 ◽  
Vol 97 (9) ◽  
pp. 1244-1244 ◽  
Author(s):  
J. Yasuhara-Bell ◽  
A. S. de Silva ◽  
A. M. Alvarez ◽  
R. Shimabuku ◽  
M. Ko
Keyword(s):  
Mangifera Indica ◽  
Infected Plant ◽  
Black Spot ◽  
The United States ◽  
Negative Control ◽  
Sterile Water ◽  
Xanthomonas Citri ◽  
Mango Fruit ◽  
First Report ◽  
16S Rdna Pcr

Bacterial black spot of mango (Mangifera indica) caused by Xanthomonas citri pv. mangiferaeindicae (Xcm), is an economically important disease in tropical and subtropical areas (3). Xcm can infect a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Fruit symptoms appear as small, water-soaked spots on the lenticels that become star-shaped, erumpent, and exude an infectious gum (3). The bacterium can also cause latent infections (2). Immature mango fruit with black spots on the epidermis were collected in August 2012 from mango trees of the cvs. Raposa and Pirie at a residence in Pukalani, Hawai'i, on the island of Maui. Similar symptoms were seen on a tree of the mango cv. Common (also known as ‘Spanish’ or ‘Lahaina’) at a nearby golf course. Mango fruit with black lesions, and leaves showing black lesions with yellow halos, were collected in August 2012 from mango trees of the cv. Haden at a residence in Kaimuki, Hawai'i, on the island of O'ahu. Xanthomonas-like bacterial colonies were isolated on TZC agar. Suspect colonies were non-pigmented on YDC agar. A fruit strain of the bacterium from Maui (A6081A) and a strain from each of a fruit (A6081B) and a leaf (A6082) from O'ahu were each gram-negative, oxidative, positive for both starch and esculin hydrolysis, and negative for nitrate reduction, resulting in presumptive identification as a Xanthomonas sp. The three strains were further characterized by Microlog (Biolog, Inc. Hayward, CA), which showed the closest match with X. campestris. In addition, 16S rDNA PCR assays showed the closest match (99% similarity) with X. citri strains, and RIF marker analysis of dnaA (4) grouped the three strains with Xcm strain LMG 941 (Accession No. CAHO01000002.1). Hypersensitivity responses typical of xanthomonads were observed when these strains were infiltrated into tobacco leaves, whereas no response was observed using sterile water. Leaves of 3-week-old mango seedlings were infiltrated using 10 μl (~108 CFU/ml) of each strain suspended in sterilized water (six to eight inoculations per leaf, four leaves per plant, and three replicate plants per strain). The negative control treatments consisted of inoculation with sterile water, as well as an incompatible pathogen, X. hortorum pv. vitians (A6076), isolated from lettuce. Typical symptoms of bacterial black spot were observed for all strains assayed approximately 2 weeks after inoculation. No lesions were observed on the negative control plants. Koch's postulates were satisfied following reisolation and identification of the Xanthomonas strains from the infected plant tissues, using the biochemical and PCR methods described above. Results for strains from the two islands confirmed published descriptions of the pathogen, indicating that the pathogen causing symptoms on these mango trees is Xcm (1). Cultures and infected plant samples were sent to USDA APHIS and CPHST NPGLB facilities where this identification was confirmed. To our knowledge, this is the first report of bacterial black spot of mango in Hawai'i or anywhere in the United States. It is unknown whether this disease is a new occurrence or has not been reported previously. The origin of the primary inoculum is unknown. References: (1) B. Manicom and F. Wallis. Int. J. Syst. Bacteriol. 34:77, 1984. (2) O. Pruvost et al. Microbial Ecol. 58:928. (3) O. Pruvost et al. Plant Dis. 95:774, 2011. (4) K. Schneider et al. PLoS 6:e18496, 2011.

scholarly journals First Report of Xanthomonas citri pv. citri Causing Asiatic Citrus Canker in Burkina Faso

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1653-1653 ◽  
Author(s):  
C. C. Juhasz ◽  
A. Leduc ◽  
C. Boyer ◽  
F. Guérin ◽  
C. Vernière ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Sweet Orange ◽  
Citrus Canker ◽  
Negative Control ◽  
Citrus Species ◽  
Xanthomonas Citri ◽  
First Report ◽  
Mexican Lime ◽  
Volkamer Lemon ◽  
Wide Range

Citrus canker, caused by Xanthomonas citri pv. citri, is a bacterial disease of economic importance in tropical and sub-tropical citrus-producing areas (EPPO-PQR online database). X. citri pv. citri causes severe infection in a wide range of citrus species, and induces erumpent, callus-like lesions with water-soaked margins leading to premature fruit drop and twig dieback. It has consequently been subjected to eradication efforts and international regulations. It was first described on the African continent in South Africa at the beginning of the 20th century, from which it was eventually eradicated. Since 2006, several outbreaks caused by phylogenetically diverse strains of X. citri pv. citri have been reported from several African countries (Ethiopia, Mali, Senegal, and Somalia). In July 2011, citrus canker in Burkina Faso was suspected in the area adjacent to the Sikassso Province of Mali where X. citri pv. citri has been confirmed. In November and December 2012, leaves of clementine (Citrus clementina), lemon (C. limon), Volkamer lemon (C. volkameriana), sweet orange (C. sinensis), tangelo (C. paradisi× C. reticulata), and mandarin (C. reticulata) were collected from orchards with trees showing symptoms of citrus canker in the Comoé, Houet, and Kénédougou provinces of Burkina Faso. Isolations performed using KC semi-selective medium (4) recovered 45 Xanthomonas-like strains. All Xanthomonas-like strains were tentatively identified as X. citri pv. citri by PCR (4/7 primers) using IAPAR 306 and sterile distilled water as the positive and negative controls, respectively (3). Among these, two strains (LK4-4 and LK4-5) produced a ‘fuscans’-like brown diffusible pigment, a phenotype never reported previously for X. citri pv. citri. MultiLocus Sequence Analysis targeting six housekeeping genes (atpD, dnaK, efp, gltA, gyrB, and lepA) (1,2) fully identified seven strains from Burkina Faso (LJ301-1, LJ303-1, LK1-1, LK2-6, LK4-3, LK4-4, and LK4-5) as X. citri pv. citri (and not to any other Xanthomonas pathovars pathogenic to citrus or host range-restricted pathotypes of pathovar citri), and more specifically as sequence type ST2 which is composed mostly of pathotype A strains of X. citri pv. citri (2). The same seven strains were inoculated to at least four leaves of each of grapefruit cv. Henderson, Mexican lime SRA 140 (C. aurantifolia), Tahiti lime SRA 58 (C. latifolia), and sweet orange cv. Washington Navel, using a detached leaf assay (2). All strains developed typical erumpent, callus-like tissue at wound sites on all citrus species inoculated. No lesions developed on the negative control (sterile 10 mM tris buffer). Koch's postulate was fulfilled after reisolation of Xanthomonas-like yellow colonies from symptoms on Mexican lime produced by the seven strains. Boiled bacterial suspensions were assayed by PCR with 4/7 primers (3) and produced the expected 468-bp amplicon in contrast with the PCR negative control. To our knowledge, this is the first report of X. citri pv. citri in Burkina Faso. Citrus canker-free nurseries and grove sanitation should be implemented for reducing the prevalence of Asiatic canker in Burkina Faso and a thorough survey of citrus nurseries and groves in the region should be conducted. References: (1) N. F. Almeida et al. Phytopathology 100:208, 2010. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) J. S. Hartung et al. Phytopathology 86:95, 1996. (4) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005.

scholarly journals First Report of Xanthomonas citri pv. citri-A* Causing Citrus Canker on Lime in Ethiopia

Plant Disease ◽  
2009 ◽  
Vol 93 (2) ◽  
pp. 203-203 ◽  
Author(s):  
E. Derso ◽  
C. Vernière ◽  
O. Pruvost
Keyword(s):  
Host Range ◽  
Rift Valley ◽  
Disease Incidence ◽  
Citrus Canker ◽  
Aflp Analysis ◽  
Xanthomonas Citri ◽  
First Report ◽  
Mexican Lime ◽  
Wide Range ◽  
Citrus Production

Asiatic citrus canker caused by Xanthomonas citri pv. citri hinders national citrus markets in tropical and subtropical areas and international trade. The bacterium induces erumpent, callus-like lesions causing defoliation, premature fruit drop, and twig dieback. Because of the damage caused by infection and reduced marketability of fruit, several countries have undergone eradication. Strains with different host ranges have been described. Pathotype A strains are the most widespread and produce canker in a wide range of citrus species. Pathotype A* strains with a host range restricted to Mexican lime (Citrus aurantifolia), Tahiti lime (C. latifolia), and alemow (C. macrophylla), but not infecting the susceptible species grapefruit (C. paradisi), were described in different areas of Asia (4). Reemergence of X. citri pv. citri pathotype A was recently described in Africa as affecting citrus production in Mali and Somalia. Canker-like infected citrus trees with symptoms on leaves, fruits, and stems were first observed in 2004 in Ethiopia in the Rift Valley Region. After a survey conducted in 2008, the disease was recorded in different areas of the Rift Valley located in the lowlands (altitude <1300 m, daily mean temperatures 24 to 29°C) and confirmed to only affect Mexican lime orchards with disease incidence as much as 80%. Ten canker-like infected leaves were collected during this survey from eight different orchards distributed along the infected area. Isolations were performed using KC semiselective medium (3), and Xanthomonas-like isolates were further characterized. PCR was used to check the identity of these isolates by using X. citri pv. citri strain CFBP 2525 from New Zealand as the positive control and distilled water as the template for the negative control. The DNA fragment typical of X. citri pv. citri was obtained from all the bacterial isolates using the diagnostic primer pair 4/7 (2). Amplified fragment length polymorphism (AFLP) analysis of the 80 Ethiopian isolates and additional reference isolates from X. citri pv. citri-A, -A*, and pv. aurantifolii using SacI/MspI and four primer pairs (unlabeled MspI + 1 [A, C, T, or G] primers and 5′-labeled-SacI + C primer for the selective amplification step) (1) grouped all the Ethiopian isolates in a cluster that was comprised of only X. citri pv. citri pathotype A* strains. On the basis of the AFLP, Ethiopian isolates were only distantly related to X. citri pv. aurantifolii. When inoculated to Mexican lime and Duncan grapefruit by a detached leaf assay (4), all of the Ethiopian strains produced canker on lime only. This confirms the larger geographical distribution of pathotype A*, and to our knowledge, is the first report of its presence on the African continent. This could allow studying the epidemiology of pathotype A* strains in a unique situation where they do not compete with pathotype A strains. The molecular characterization of Ethiopian strains suggests that this introduction event is not related to the recent introduction of citrus canker in neighboring Somalia where X. citri pv. citri pathotype A was identified. Ethiopia will have to prevent the introduction of this wide host range pathotype to avoid further negative impacts on citrus production. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) J. S. Hartung et al. Phytopathology 86:95, 1996. (3) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (4) C. Vernière et al. Eur. J. Plant Pathol. 104:477, 1998.

scholarly journals First Report in Myanmar of Xanthomonas axonopodis pv. mangiferaeindicae Causing Mango Bacterial Canker on Mangifera indica

Plant Disease ◽  
2007 ◽  
Vol 91 (12) ◽  
pp. 1686-1686
Author(s):  
N. Ah-You ◽  
L. Gagnevin ◽  
O. Pruvost ◽  
N. T. Myint ◽  
G. I. Johnson
Keyword(s):  
Mangifera Indica ◽  
Black Spot ◽  
Severe Infection ◽  
Polymorphism Analysis ◽  
Bacterial Canker ◽  
Xanthomonas Axonopodis ◽  
Small Water ◽  
Infection Pattern ◽  
Strain Collection ◽  
Wide Range

Bacterial canker of mango (or bacterial black spot) caused by Xanthomonas axonopodis pv. mangiferaeindicae (1) is a disease of economic importance in tropical and subtropical producing areas. X. axonopodis pv. mangiferaeindicae can cause severe infection in a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Several months after infection, leaf lesions dry and turn light brown or ash gray. Severe leaf infection may result in abscission. Fruit symptoms appear as small, water-soaked spots on the lenticels. These spots later become star shaped, erumpent, and exude an infectious gum. Often, a “tear stain” infection pattern is observed on the fruit. Severe fruit infections will cause premature fruit drop. Twig cankers are potential sources of inoculum and weaken branch resistance to winds (2). Suspected leaf lesions of bacterial canker were collected from mango nursery stock cv. Yin Kwe at a nursery in Yangon, Myanmar during March 2007. Nonpigmented Xanthomonas-like bacterial colonies were isolated on KC and NCTM3 semiselective agar media (4). Amplified fragment length polymorphism analysis was performed on three isolates from Myanmar and additional reference isolates of xanthomonads originating from Anacardiaceae (X. axonopodis pv. anacardii, X. axonopodis pv. mangiferaeindicae, X. axonopodis pv. spondiae, and X. translucens strains from pistachio) using SacI/MspI and four primer pairs (unlabeled MspI + 1 [A, C, T, or G] primers and 5′-labeled - SacI + C primer for the selective amplification step) (1). On the basis of multidimensional scaling (1), the Myanmar isolates were identified as X. axonopodis pv. mangiferaeindicae and were most closely related to group B strains that were isolated from mango in India and Eastern Asia (2). Mango cv. Maison Rouge leaves, inoculated as previously reported (1) with the Myanmar isolates, showed typical symptoms of bacterial canker 1 week after inoculation. One month after inoculation, mean X. axonopodis pv. mangiferaeindicae population sizes ranging from 5 × 106 to 8 × 106 CFU per lesion were recovered from leaf lesions, typical of a compatible interaction (1). Mangifera indica L. probably evolved in the area that includes northwestern Myanmar (3) and to our knowledge, this is the first confirmed detection of X. axonopodis pv. mangiferaeindicae from Myanmar. Further surveys and strain collection will be necessary to evaluate its geographic distribution and prevalence in the country. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) L. Gagnevin and O. Pruvost. Plant Dis. 85:928, 2001. (3) S. K. Mukherjee. Page 1 in: The Mango, Botany, Production and Uses. R. E. Litz, ed. CAB International, Wallingford, UK, 1997. (4) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005.

scholarly journals First Report of Sequence Type 1, Pathotype A Xanthomonas citri pv. citri from Lime and Lemon Fruit Originating from Bangladesh

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 836-836 ◽  
Author(s):  
C. Vernière ◽  
K. Vital ◽  
C. Boyer ◽  
O. Pruvost ◽  
B. A. Carter
Keyword(s):  
Indian Subcontinent ◽  
Acid Methyl Ester ◽  
Negative Control ◽  
Aflp Analysis ◽  
The European Union ◽  
Xanthomonas Citri ◽  
Long Distance ◽  
Bootstrap Analysis ◽  
First Report ◽  
Wide Range

Asiatic canker caused by Xanthomonas citri pv. citri, a quarantine pest in several countries (including the European Union), strongly impacts both national citrus markets in tropical and subtropical areas and international trade. This bacterium induces erumpent, callus-like lesions often with a water-soaked margin in a wide range of citrus species causing premature fruit drop and twig dieback. Long distance dispersal is mainly through infected propagative material and the role of fruit is still debated. During inspection of imported limes (C. aurantifolia) and lemons (C. limon) from Bangladesh from 2006 to 2009, canker-like infected fruits were intercepted by the UK plant health service. Typical corky lesions were surface sterilized and comminuted in 0.1% peptone solution. Suspensions were plated onto nutrient dextrose (ND) and yeast dextrose chalk (YDC) plates for bacterial isolation. After incubation for 3 to 7 days at 25°C, typical Xanthomonas-like yellow colonies were purified for identification. Identification of 18 isolates as Xanthomonas was carried out initially by fatty acid methyl ester (FAME) analysis. Identification at the species level (X. citri) was completed by sequencing of the gyrase B gene (4). PCR (3) was used to confirm the identity of these isolates using X. citri pv. citri CFBP 2525 as the positive control and distilled water as the negative control. The expected DNA fragment was only obtained from all of the bacterial isolates using primer pair 4/7 (3). Multilocus sequence analysis (MLSA) of four housekeeping genes (atpD, dnaK, efp, and gyrB) identified isolates from Bangladesh as two sequence types of X. citri pv. citri, ST1 (n = 5; GenBank Accession Nos. FJ376118, FJ376168, FJ376216, and FJ376251) and ST2 (n = 13; EU333904, EU333907, EU333910, and FJ376357), but not as any other xanthomonad pathogenic to citrus (2). Amplified fragment length polymorphism (AFLP) analysis of all X. citri pv. citri isolates from Bangladesh and additional reference isolates from pathotype A, A*, Aw and X. citri pv. aurantifolii (2) using Sac I/Msp I and four primer pairs (unlabelled MspI + 1 (A, C, T, or G) primers and 5′-labeled – SacI + C primer for the selective amplification step) confirmed identification as X. citri pv. citri. All five ST1 isolates grouped as a single cluster by AFLP, although not strongly supported by bootstrap analysis. Evolutionary genome divergences (EGD) computed from AFLP data ranged from 0.0000 to 0.0097 (median EGD 0.0055) suggested a relatively wide diversity within isolates originating from Bangladesh (median EGD from a worldwide pathotype A collection [n = 73] 0.0028) (2). When inoculated to Mexican lime SRA 140 and grapefruit cv. Duncan using a detached leaf assay (2), all the Bangladesh isolates produced typical extensive canker lesions on both species whereas the negative control (10 mM Tris buffer pH 7.2) did not, and Koch's postulates were fulfilled. To our knowledge, this is the first report of pathotype A assigned to ST1 by MLSA. All strains previously assigned to ST1 displayed a narrow host range (pathotype A*) (2). Our results further identify the Indian subcontinent as an area of relatively wide genetic diversity of X. citri pv. citri (1). References: (1) L. Bui Thi Ngoc et al. Appl. Environ. Microbiol. 75:1173, 2009. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) J. S. Hartung et al. Phytopathology 86:95, 1996. (4) N. Parkinson et al. Int. J. Syst. Evol. Microbiol. 57:2881, 2007.

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