First Report of Alternaria alternata Causing Postharvest Black Spot of Fresh Date Palm Fruit in Spain

Commercial production of date palm fruit (Phoenix dactylifera L.) for fresh consumption has increased in the grove of Elx (Alacant Province, southeast Spain) after the successful development of tissue culture technologies and induced ripening and cold storage protocols. In a survey of losses after harvest, disease symptoms consisting of superficial, small, and firm black spots irregularly distributed throughout the fruit skin were observed in commercially handled and cold-stored fruit. At room temperature, superficial lesions expanded and produced dark mycelium. The potential causal agent was transferred to potato dextrose agar (PDA), incubated at 25°C in darkness, and subcultured on PDA. The identification was performed at the Spanish Type Culture Collection (CECT, University of Valencia, Spain) using colony morphology on PDA and malt extract agar at 26 or 37°C. At 26°C, the fungus rapidly produced cottony white mycelium that turned olivaceous and dark brown to black. Conidiophores were simple, straight or bent, with plain walls. Conidia were brown, obpyriform to ellipsoid (average 22 to 39 × 8 to 15 μm; n = 50), with both transversal and longitudinal septa, often observed in branched chains with more than 5 conidia. Growth occurred at 37°C. The identification of Alternaria alternata (Fr.:Fr.) Keissler was confirmed by the amplification and subsequent sequencing with the primers NL1 and NL4 of the region D1/D2 in the 5′ end of the 28S rRNA gene of the isolate IVIA DAA-4 (GenBank Accession No. JX987100). A BLAST search showed 100% identity with A. alternata strain DAOM 216376 (JN938894). Selected healthy ‘Medjool’ dates were surface disinfected by dipping them for 2 min in a 0.5% sodium hypochlorite solution and thoroughly rinsed with fresh water. To fulfill Koch's postulates, 20 μl of a spore suspension at 1 × 105 spores per ml prepared from 7-day-old colonies grown on PDA were placed in fresh skin wounds made in disinfected fruit using a sterile stainless steel rod with a probe tip 1 mm wide and 2 mm in length (one wound per fruit; three humid chambers with nine fruits each). Wounded but not inoculated fruit were used as controls (one humid chamber with nine fruit). While disease symptoms were observed on all fruit inoculated with A. alternata (average black spots of 3, 6, and 12 mm after 4, 7, and 10 days of incubation at 20°C), no decay was observed on any of the control fruit. Reisolation of the fungus was performed from 10 infected dates and it was positive in all cases. A. alternata has been reported to cause date palm fruit disease in Israel (1) and Egypt (2), whereas Alternaria spp. have been cited in California (3) and Iran (4). To our knowledge, this is the first report of A. alternata causing date palm fruit rot in Spain. References: (1) R. Barkai-Golan et al. Hassadeh 69:1446, 1989. (2) H. M. El-Deeb et al. Acta Hort. 736:421, 2007. (3) H. S. Fawcett and L. J. Klotz. University of California Bulletin 522, 1932. (4) F. Karampourland and H. Pejman. Acta Hort. 736:431, 2007.

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First Report of Penicillium expansum Causing Postharvest Blue Mold of Fresh Date Palm Fruit (Phoenix dactylifera) in Spain

Plant Disease ◽

10.1094/pdis-11-12-1097-pdn ◽

2013 ◽

Vol 97 (6) ◽

pp. 846-846 ◽

Cited By ~ 4

Author(s):

L. Palou ◽

C. Montesinos-Herrero ◽

V. Taberner ◽

J. Vilella-Esplá

Keyword(s):

Date Palm ◽

Phoenix Dactylifera ◽

Penicillium Expansum ◽

Blue Mold ◽

Palm Fruit ◽

Centraalbureau Voor ◽

Disease Symptoms ◽

First Report ◽

Extract Agar ◽

Query Coverage

A survey of postharvest losses of commercially handled and cold-stored fruit of fresh date palm (Phoenix dactylifera L.), cvs. Medjool and Hayani, was conducted in the 2009 and 2010 seasons in the grove of Elx (Alacant Province, Southeast Spain). Disease symptoms consisting of circular, light brown, soft spots located in any part of the fruit skin were observed in 2 to 5% of the fruit. At room temperature, the lesions expanded rapidly and blue mold symptoms were apparent. The potential causal agent (isolate IVIA NiAA-2) was transferred to PDA and incubated at 25°C. The identification was performed at the Spanish Type Culture Collection (CECT, University of Valencia, Spain) based on colony morphology of the isolate grown on Czapeck yeast extract agar (CYA) and malt extract agar (MEA) at 26°C. Colonies were circular (average diameter of 40 mm at 7 days), radially sulcate, with dense velvety white mycelium, and very abundant, bluish green conidia. The underside of the plates showed light brown and pale green colonies on CYA and MEA, respectively. On CYA, but not on MEA, a light yellow exudate was produced and a brownish pigment diffused into the medium. At 5 and 37°C on CYA, white microcolonies and no colonies were observed, respectively. Conidia were ellipsoidal to subglobose, smooth and thin walled, measuring 3.0 to 3.5 × 2.5 to 3.0 μm (n = 50) (4). Based on these morphological characteristics, the isolate IVIA NiAA-2 was tentatively identified as Penicillium expansum L. To confirm the identity, we amplified and sequenced the rDNA internal transcribed spacer (ITS) region with primers ITS1 and ITS4 (GenBank Accession No. KC169942). A BLAST search showed 99% identity and 100% query coverage with P. expansum strain NRRL 6069 (DQ339562) (2). Selected healthy dates cv. Medjool were surface disinfected by dipping in 0.5% sodium hypochlorite for 2 min followed by thorough rinsing in deionized water. Pathogenicity was tested by pipetting 20 μl of a spore suspension (1 × 106 spores per ml), prepared from 7-day PDA cultures, onto fresh skin wounds, which were made on disinfected fruit using a sterile, stainless steel rod with a probe tip 1 mm in width × 2 mm in length (one wound on each of nine dates, incubated in one humid chamber). Disinfected, wounded, and non-inoculated dates were used as controls. The procedure was repeated three times. Disease symptoms were observed on all inoculated fruit (average lesion size of 6, 15, and 22 mm after 4, 7, and 10 days of incubation at 20°C, respectively) and P. expansum was consistently reisolated, thereby fulfilling Koch's postulates. No decay was observed on any of the non-inoculated fruit. Unidentified species of Penicillium have been reported to cause date palm fruit rot (1,3). To our knowledge, this is the first report of P. expansum causing postharvest decay of date palm fruit in Spain. References: (1) M. Djerbi. Diseases of the Date Palm. FAO Regional Project, Rome, 1983. (2) M. A. Dombrink-Kurtzman. Antonie Van Leeuwenhoek 91:179, 2007. (3) S. Ibrahim and M. A. Rahma. Bayero J. Pure Appl. Sci. 2:127, 2009. (4) R. A. Samson et al. Introduction to Food-Borne Fungi. Centraalbureau voor Schimmelcultures, Baarn, the Netherlands, 1995.

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First Report of Ditylenchus dipsaci on Garlic in Minnesota

Plant Disease ◽

10.1094/pdis-06-12-0532-pdn ◽

2012 ◽

Vol 96 (11) ◽

pp. 1707-1707 ◽

Cited By ~ 4

Author(s):

D. S. Mollov ◽

S. A. Subbotin ◽

Carl Rosen

Keyword(s):

The Body ◽

Parasitic Nematodes ◽

Rrna Gene ◽

28S Rrna ◽

Gene Sequences ◽

Surrounding Water ◽

Pharyngeal Bulb ◽

First Report ◽

Plant Parts ◽

Ditylenchus Dipsaci

In the summer of 2011, two independent garlic samples from Morrison and Dakota counties and in 2012 one garlic sample from Carver county in Minnesota were submitted by commercial growers to the University of Minnesota Plant Disease Clinic for disease analyses. Symptoms of the above-ground plant parts were stunting and chlorosis. Symptoms of bulbs were necrosis, underdevelopment, and distortion. Upon microscopic examination, phytonematodes exuded into the surrounding water droplet. Nematodes were present in the protective leaves, abscission zone, and cloves in all submitted bulbs (n = 18) for analyses. Morphometric examination of females, males, and juveniles determined that they were Ditylenchus dipsaci. Nematodes extracted from garlic cloves were fixed in TAF (97 ml formalin [40%], 2 ml triethanolamine, and 91 ml dH2O). Morphological observations and measurements were made under an Olympus BX51 microscope equipped with a Nomarski differential interference contrast. Female (n = 6) measurements were: L = 1.411 to 1.636 mm, a = 38 to 44, b = 5.8 to 8.0, c = 14 to 17, stylet = 11.5 to 12.3 μm, V = 79 to 81%, and tail = 95 to 105 μm. The body was almost straight, when heat relaxed, lip region flattened, median bulb oval, and isthmus elongate and slender. The basal pharyngeal bulb overlapped the intestine. The post-vulval uterine branch was about half of vulva-anus distance. The tail was conoid with a pointed terminus. Male (n = 9) measurements were: L = 1.372 to 1.558 mm, a = 40 to 50, b = 6.5 to 7.0, c = 14 to 16, stylet = 11.5 to 12.3 μm, spicules = 22 to 27 μm, and gubernaculum = 9 to 10 μm. The bursa was leptoderan and spicules were curved with simple gubernaculum. Morphology and morphometrics of females and males of D. dipsaci from Minnesota generally fit the descriptions provided for the type and other populations by Hopper (1) and other authors. Several specimens were also taken for molecular identification. DNA extraction, PCR, and sequencing protocols were as described by Subbotin et al. (2). The TW81 and AB28 primers were used for amplification of ITS-rRNA region and the D2A and D3B primers were used for amplification of the D2-D3 expansion segments of 28S rRNA gene. Comparison of the ITS and D2-D3 of 28 rRNA gene sequences showed 100 and 99% identity with corresponding gene sequences of D. dipsaci published in the GenBank (2). The sequences were submitted in the GenBank under accession numbers JX123258 and X123259. This nematode problem has not been known to occur in either of these locations previously. The most likely source of introduction of D. dipsaci are imported garlic seed bulbs. To our knowledge, this is the first report of D. dipsaci affecting garlic or any other crops in Minnesota. The garlic produced in these locations was considered unmarketable and complete loss to the farmers. The presence of D. dipsaci could have a significant economic impact in the emerging multi-million dollar garlic industry in Minnesota. References: (1) D. J. Hooper. Ditylenchus dipsaci. CIH Descriptions of Plant-Parasitic Nematodes Set 1, No. 14, 1972. (2) S. A. Subbotin et al. Phytopathology 95:1308, 2005.

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First Report of Clover Proliferation Phytoplasma in Strawberry

Plant Disease ◽

10.1094/pdis.1999.83.10.967c ◽

1999 ◽

Vol 83 (10) ◽

pp. 967-967 ◽

Cited By ~ 4

Author(s):

R. Jomantiene ◽

J. L. Maas ◽

E. L. Dally ◽

R. E. Davis ◽

J. D. Postman

Keyword(s):

Dna Sequences ◽

Rrna Gene ◽

Universal Primer ◽

Disease Symptoms ◽

First Report ◽

Chain Reactions ◽

Polymerase Chain Reactions ◽

Fragaria Virginiana ◽

Phytoplasma Infection ◽

Group 2

In 1996, diseased plants of Fragaria virginiana Duchesne were collected from a native population in Quebec, Canada, and sent to the National Clonal Germplasm Repository in Corvallis, OR, where grafting onto disease-free plants of F. chiloensis (L.) Duchesne (4) was performed. Plants of both species were sent to Beltsville, MD, for identification of a phytoplasma possibly associated with the disease symptoms of dwarfing and multibranching crowns. A phytoplasma was found in both species and characterized as the strawberry “multicipita” (SM) phytoplasma, which is representative of subgroup 16SrVI-B, a new subgroup of the clover proliferation (CP) group (2). In 1999, we observed commercial strawberry (Fragaria × ananassa Duchesne) plants collected in California and Maryland that were stunted and chlorotic or exhibited these symptoms in addition to small, distorted leaves. Infected F. × ananassa plants, as well as diseased F. virginiana and grafted F. chiloensis plants previously infected by the SM phytoplasma, were assessed for phytoplasma infection by nested polymerase chain reactions primed by phytoplasma universal primer pairs R16mF2/R1 and F2n/R2 (1) or P1/P7 (3) and F2n/R2 for amplification of phytoplasma 16S rDNA (16S rRNA gene) sequences. Phytoplasma-characteristic 1.2-kbp DNA sequences were amplified from all diseased plants. No DNA sequences were amplified from healthy plants. Restriction fragment length polymorphism patterns of rDNA digested with AluI, KpnI, HhaI, HaeIII, HinfI, HpaII, MseI, RsaI, and Sau3A1 endonucleases indicated that all plants were infected by a phytoplasma that belonged to subgroup 16SrVI-A (CP phytoplasma subgroup) and that diseased F. virginiana and grafted F. chiloensis plants were infected by both SM and CP. This is the first report of the CP phytoplasma, subgroup 16SrVI-A, infecting strawberry. This report also indicates that the occurrence of the CP phytoplasma in strawberry may be widespread in North America and that F. chiloensis, F. virginiana, and F. × ananassa plants are susceptible to infection by the CP phytoplasma. References: (1) D. E. Gunderson and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (2) R. Jomantiene et al. HortScience 33:1069, 1998. (3) R. Jomantiene et al. Int. J. Syst. Bacteriol. 48:269, 1998. (4) J. D. Postman et al. Acta Hortic. 471:25, 1998.

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First Report of Sphaeropsis Rot of Apple Caused by Sphaeropsis pyriputrescens in New York

Plant Disease ◽

10.1094/pdis-03-13-0320-pdn ◽

2013 ◽

Vol 97 (9) ◽

pp. 1257-1257 ◽

Cited By ~ 4

Author(s):

Y. K. Kim ◽

R. Caiazzo ◽

P. Sikdar ◽

C. L. Xiao

Keyword(s):

New York ◽

New York State ◽

Apple Fruit ◽

Fruit Rot ◽

Economic Losses ◽

Sodium Hypochlorite Solution ◽

First Report ◽

Control Fruit ◽

Representative Isolate ◽

Sphaeropsis Rot

In March 2012, decayed ‘Empire’ apple fruit (Malus × domestica Borkh.) were sampled from apples grown in Albion (Orleans County) in New York State and stored in bins for 6 months under controlled atmosphere at a commercial packinghouse. At the packinghouse following storage prior to be packed, the fruit were completely rotten, spongy to firm, and light brown without pycnidia. All fruit rots originated from either stem-end or calyx-end infections but no wound infections were observed. The incidence of fruit with these symptoms in the total decay was relatively low (0.1%). To isolate the causal agent, small fragments of fruit flesh from 12 decayed fruit were cut and placed on potato dextrose agar (PDA) acidified with 0.1% lactic acid. The plates were incubated at 20°C for 4 days and sub-cultured on PDA to obtain a pure culture. The colonies initially appeared with dense hyaline mycelium and later turned light yellow to yellow, and black pycnidia formed after about 2 weeks of incubation under a 24-h fluorescent light at 20°C. Conidia were light brown to brown, clavate to subglobose to irregular, and 15 × 8 μm on average. The fungus was identified as Sphaeropsis pyriputrescens Xiao & J.D. Rogers based on the morphology of the fungus (3). The identity of a representative isolate was further confirmed by analysis of nucleotide sequences of the internal transcribed spacer (ITS) regions amplified using the primers ITS1/ITS4. A BLAST search in GenBank showed that the sequence had 99% homology to an S. pyriputrescens sequence (Accession No. GQ374241). One representative isolate was tested for pathogenicity on apple fruit. Organic ‘Red Delicious’ apple fruit were surface-disinfected in 0.6% sodium hypochlorite solution for 5 min, rinsed twice with deionized water, and air-dried. Each fruit was wounded with a sterilized finish-nail head (3 mm in depth and 4 mm in diameter) and inoculated by placing a 4-mm-diameter plug from the leading edge of a 4-day-old PDA culture on the wound. Control fruit were treated with sterile PDA plugs. The inoculation site was covered with two layers of moist cheesecloth to avoid dehydration. There were four 10-fruit replicates for each treatment, and fruit were placed in plastic crispers and stored at 4°C for 4 weeks. The experiments were conducted twice. Sphaeropsis rot developed on all inoculated fruit, while no decays appeared on the control fruit. Koch's postulates were fulfilled by reisolating the fungus from the decayed fruit. Sphaeropsis rot is a recently reported postharvest fruit rot disease of apple and pear (1,3). The disease was first observed on ‘d'Anjou’ pears, and later more serious economic losses were observed in apples in Washington State (1). The disease has also since been reported in British Columbia, Canada (2). To the best of our knowledge, this is the first report of the occurrence of Sphaeropsis rot caused by S. pyriputrescens on apple in New York or in any region outside of the Pacific Northwest in North America. References: (1) Y. K. Kim and C. L. Xiao. Plant Dis. 92:940, 2008. (2) P. L. Sholberg et al. Plant Dis. 93:843, 2009. (3) C. L. Xiao et al. Plant Dis. 88:223, 2004.

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First Report of Alternaria alternata Causing Postharvest Fruit Rot of Lychee in Pakistan

Plant Disease ◽

10.1094/pdis-10-16-1452-pdn ◽

2017 ◽

Vol 101 (6) ◽

pp. 1041 ◽

Cited By ~ 5

Author(s):

M. W. Alam ◽

A. Rehman ◽

M. L. Gleason ◽

A. S. Khan ◽

M. Amin ◽

...

Keyword(s):

Alternaria Alternata ◽

Fruit Rot ◽

First Report

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First Report of Alternaria alternata causing fruit Rot on Tetradium ruticarpum in China

Plant Disease ◽

10.1094/pdis-08-20-1853-pdn ◽

2020 ◽

Author(s):

Miaolian Xiang ◽

Shucheng Li ◽

Fan Wu ◽

Xianyang Zhao ◽

Yinbao Wang ◽

...

Keyword(s):

Relative Humidity ◽

Alternaria Alternata ◽

Sequence Data ◽

Elongation Factor ◽

Fruit Rot ◽

Effective Control ◽

Molecular Characteristics ◽

Sterile Water ◽

First Report ◽

Initial Symptoms

Tetradium ruticarpum, previously and commonly known as Evodia rutaecarpa, is a tree that produces a fruit which is one of the most important traditional Chinese medicine herbs in China (Zhao et al. 2015). In July 2019, an investigation of diseases of T. ruticarpum was conducted in the farmland of Ruichang County (29.68° N, 115.65° E), Jiujiang City, China. An unknown fruit rot disease was observed and the incidence rate was estimated to be 60% to 70% within a 5,000 m2 area. The early symptoms appeared as small circular to irregular dark brown or black spots on the fruit, which gradually coalesced to a light brown-to-black discoloration and caused fruit rot. To identify the causal agent of the disease, 10 diseased fruits were collected and surface disinfected with 2% sodium hypochlorite for 2 min, 70% ethanol for 30 s, rinsed in sterile water and dried on filter paper. Tissues from non-symptomatic tissue as well as from the margin between healthy and affected edge were incubated on potato dextrose agar (PDA) at 25±1°C (12 h light/dark) with 90% relative humidity for 5 days. The colonies were brown to black with abundant whitish margins. Conidiophores were brown and measured 20.40 – 43.10×1.30 – 4.20 μm (25.47 × 2.35 µm on average, n=50). Conidia produced in single or branched chains, were obclavate or ovoid, approximately 9.90 – 32.80×6.50 – 14.50 μm (28.75×12.57 µm on average, n=50) with 2 to 5 transverse septa and 0 to 3 longitudinal septa. The colonies were consistent with Alternaria alternata (Simmons 2007). For molecular identification, the f partial internal transcribed spacer (ITS) regions, Glyceraldehyde-3-phosphate dehydrogenase (gapdh) genes, translation elongation factor 1-alpha (TEF) and Alternaria major allergen (Alt a1) gene of the isolate were amplified using primers ITS1/ITS4 (White et al. 1990), GDF/GDR (Templeton et al. 1992), EF1-728F/EF1-986R (Carbone and Kohn 1999) and Alt-for/Alt-rev (Hong et al. 2005). Sequence data showed 100% homology to A. alternata (GenBank accessions No.MN625176.1 (570/570 bp), MK683866.1 (618/618 bp), MK637432.1 (281/281 bp), KT315515.1 (488/488 bp)), respectively and the sequence data were deposited into GenBank with accession numbers MN897753 (ITS), MT041998 (gapdh), MT041999 (TEF), and MT042000 (Alt a1). Based on both morphological and molecular characteristics, the pathogen was identified as A. alternata. To confirm pathogenicity, 10 μl of a spore suspension (1.0 × 106 conidia/ml) obtained from 5-day-old PDA cultures of the strain were inoculated on 20 wounded (using sterile needle) and 20 nonwounded healthy T. ruticarpum fruits previously disinfected in 75% ethanol. Control fruits including 20 wounded fruits and 20 nonwounded fruits were inoculated with sterilized water. All fruits were incubated at 25±1°C (12 h light/dark) with 90% relative humidity. Four days later, all the wounded and non-wounded fruits showed the initial symptoms of black rot which was similar to that observed in the field, while the wounded and nonwounded fruits treated with sterile water remained healthy. The same pathogen was again isolated from the inoculated fruits. The pathogenicity experiment was repeated three times with the same results. As far as we know, this is the first report of A. alternata causing fruits rot on T. ruticarpum in China, and the identification of the pathogen will provide useful information for developing effective control strategies.

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First Report of Phaeoacremonium krajdenii Causing Petri Disease of Grapevine in Spain

Plant Disease ◽

10.1094/pdis-11-10-0808 ◽

2011 ◽

Vol 95 (5) ◽

pp. 615-615 ◽

Cited By ~ 3

Author(s):

D. Gramaje ◽

M. I. Aguilar ◽

J. Armengol

Keyword(s):

Tap Water ◽

Vitis Vinifera L ◽

Sodium Hypochlorite Solution ◽

Malt Extract ◽

First Report ◽

Worldwide Distribution ◽

Black Spots ◽

Pathogenicity Tests ◽

Weak Growth ◽

Human Infections

In September 2009, symptoms of grapevine (Vitis vinifera L.) decline were observed on 3-year-old grapevines in a vineyard in Roquetas de Mar (Almeria Province, southern Spain). Affected vines were weak with reduced foliage and chlorotic leaves. Black spots and dark streaking of the xylem vessels could be seen in cross- or longitudinal sections of the rootstock trunk. Symptomatic plants were collected and sections (10 cm long) were cut from the basal end of the rootstocks, washed under running tap water, surface disinfested for 1 min in a 1.5% sodium hypochlorite solution, and washed twice with sterile distilled water. The sections were split longitudinally and small pieces of discolored tissues were plated onto malt extract agar (MEA) supplemented with 0.5 g liter–1 of streptomycin sulfate. Dishes were incubated at 25 to 26°C in the dark for 14 to 21 days, and all colonies were transferred to potato dextrose agar (PDA). A Phaeoacremonium sp. was consistently isolated from necrotic tissues. Single conidial isolates were obtained and grown on PDA and MEA in the dark at 25°C for 2 to 3 weeks until colonies produced spores (2). Colonies were grayish brown on PDA and dark brown on MEA. Conidiophores were short and unbranched and 11.5 to 46 (25.5) μm long. Phialides were often polyphialidic. Conidia were hyaline, oblong-ellipsoidal or allantoid, 2.5 to 5 (4.2) μm long, and 1 to 1.7 (1.2) μm wide. On the basis of these characters, the isolates were identified as Phaeoacremonium krajdenii L. Mostert, Summerb. & Crous (1,2). DNA sequencing of a fragment of the beta-tubulin gene of the isolate (Pkr-1) using primers T1 and Bt2b (GenBank Accession No. HM637892) matched P. krajdenii GenBank Accession No. AY579330. Pathogenicity tests were conducted using isolate Pkr-1. Ten 1-year-old callused and rooted cuttings of 110 R rootstock grown in pots with sterile peat were wounded at the uppermost internode with an 8-mm cork borer. A 5-mm mycelium PDA plug from a 2-week-old culture was placed in the wound before being wrapped with Parafilm. Ten control plants were inoculated with 5-mm noncolonized PDA plugs. Plants were maintained in a greenhouse at 25 to 30°C. Within 3 months, shoots on all Phaeoacremonium-inoculated cuttings had weak growth with small leaves and short internodes and there were black streaks in the xylem vessels. The vascular necroses that developed on the inoculated plants were 5.5 ± 1.2 cm long, significantly greater than those on the control plants (P < 0.01). Control plants did not show any symptoms. The fungus was reisolated from discolored tissue of all inoculated cuttings, completing Koch's postulates. P. krajdenii has a worldwide distribution, although these reports are from human infections (1). P. krajdenii was first reported as a pathogen of grapevines in South Africa (1). To our knowledge, this is the first report of P. krajdenii causing young grapevine decline in Spain or any country in Europe. References: (1) L. Mostert et al. J. Clin. Microbiol. 43:1752, 2005. (2) L. Mostert et al. Stud. Mycol. 54:1, 2006.

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First Report of Alternaria alternata Causing Postharvest Fruit Rot of Syzygium cumini (Jamun) in Pakistan

Plant Disease ◽

10.1094/pdis-04-19-0858-pdn ◽

2019 ◽

Vol 103 (10) ◽

pp. 2693-2693 ◽

Cited By ~ 1

Author(s):

T. Ahmad ◽

Y. Liu ◽

A. Moosa ◽

A. Farzand ◽

Y. Zhao ◽

...

Keyword(s):

Alternaria Alternata ◽

Fruit Rot ◽

Syzygium Cumini ◽

First Report

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First Report of Alternaria alternata Causing Fruit Rot of Grapes in Pakistan

Plant Disease ◽

10.1094/pdis-01-18-0096-pdn ◽

2018 ◽

Vol 102 (8) ◽

pp. 1659-1659 ◽

Cited By ~ 1

Author(s):

S. Ghuffar ◽

G. Irshad ◽

M. Shahid ◽

F. Naz ◽

A. Riaz ◽

...

Keyword(s):

Alternaria Alternata ◽

Fruit Rot ◽

First Report

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First Report of Boll Rot of Cotton Caused by Pantoea agglomerans in China

Plant Disease ◽

10.1094/pdis-92-9-1364b ◽

2008 ◽

Vol 92 (9) ◽

pp. 1364-1364 ◽

Cited By ~ 10

Author(s):

Y. Z. Ren ◽

Y. Q. Liu ◽

S. L. Ding ◽

G. Y. Li ◽

H. Zhang

Keyword(s):

16S Rdna ◽

The United States ◽

Cell Suspensions ◽

Pantoea Agglomerans ◽

Universal Primers ◽

Rrna Gene ◽

Disease Symptoms ◽

First Report ◽

Boll Rot ◽

Cotton Bolls

Since the summer of 2006, bacterial boll rot of cotton has been observed on fruits of ‘Xinluzao 31’ (Xinluzao 6 × Acala) in Xinjiang Province. It resulted in as much as 20% yield loss in several fields. Symptoms do not appear on the outer carpel. In the infected cotton bolls, fibers do not mature completely and seed tissue exhibits brown necrotic coloration. Lint and seeds from 24 surface-disinfested cotton bolls were triturated and plated onto King's medium B (KB). Plates were incubated at 28°C for 48 h. Forty eight strains with yellow pigmentation on KB were characterized. All were nonfluorescent on KB, gram negative, facultatively anaerobic, unable to produce indole from tryptophan, able to reduce nitrate to nitrite, and produce acid from glucose, cellobiose, lactose, melibiose, and melonate. In addition, 16S rDNA in seven strains was amplified with universal primers (1). The PCR products were cloned into pGEM-T easy vector and sequenced. A BLAST search of the seven sequences against the GenBank nucleotide library indicated 100% identity with the 16S rDNA sequence of Enterobacter agglomerans strain A80. Then an additional primer pair, pagF and pagR (3), was used for more specific amplification of Pantoea agglomerans 16S rDNA, which resulted in single highly specific fragments of approximately 1 kb. On the basis of morphological, physiological, biochemical characteristics, and 16S rRNA gene sequence analysis, we identified the bacterium to be P. agglomerans. To confirm pathogenicity, cell suspensions (1 × 108 CFU/ml) of eight representative strains were used to inoculate cotton at peak bolling stage in the field. Cell suspensions, or water as the control, were applied to stigma scars, wall sutures, and scratch wounds on bracts, calyxes, and bolls. Alternatively, a needle was used to puncture through a drop of suspension placed on the boll wall suture and bracts. At least 20 bolls or flowers were inoculated with each bacterial strain per inoculation method. Infection occurred only when bacterial injections breached the endocarp of the boll either through the carpel wall or a suture between carpel sections. Disease symptoms developed 1 week postinoculation. The inoculated organism was reisolated from the diseased tissues. P. agglomerans is generally regarded to be a soil saprophyte or leaf epiphyte, but strains can opportunistically infect plants triggering gall formations or human wounds causing septic arthritis. The disease symptoms and pathogen characteristics observed in this study are identical to those reported in the United States (2). To our knowledge, this is the first report of P. agglomerans causing boll rot of cotton in China. References: (1) S. Manulisi and I. Barash. Mol. Plant Pathol. 4:307, 2003. (2) E. G. Medrano et al. J. Appl. Microbiol. 103:436, 2007. (3) S. Vorwerk et al. Agric. For. Entomol. 9:57, 2007.

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