First Report of Rhizome Rot on Ginger (Zingiber officinale) Caused by Enterobacter cloacae in Shandong Province, China

Ginger (Zingiber officinale Roscoe) is an important commercial crop that is planted in 60,000 to 70,000 ha every year in Shandong Province, China. In 2010, rotted rhizomes of cultivar Laiwu Big Ginger were reported on 20 ha in Anqiu, Shandong Province, and yield losses of up to 70% were reported. The aboveground symptoms were the water-conducting portion of symptomatic rhizomes was discolored brown and had a black dry rot of the cortex tissues (3). Thirty symptomatic rhizomes were sampled from six fields in six farms. Komada's method (1) was used to isolate the pathogen. Ten pieces from each rhizome were washed with sterile distilled water and plated on Komada selective medium at 25°C. White fungal colonies turned orchid after 7 days of incubation. Two types of asexual spores were associated with the colonies: microconidia and macroconidia. The microconidia were the most abundantly produced spores and were oval, elliptical or kidney shaped, and produced on aerial mycelia. Macroconidia had three to five cells and gradually pointed or curved edges, varied in size from 3 to 5 × 19 to 36 μm. The rDNA of the internal transcribed spacer regions 1 and 2 and the 5.8S gene in five isolates were amplified using primers ITS1 and ITS4, and the nucleotide sequence was the same as isolate no. 3, which was deposited in GenBank (Accession No. KC594035). A BLAST search showed 99% identity with the strain Z9 of Fusarium oxysporum (EF611088). Pathogenicity tests of five isolates were carried out in a greenhouse and the pathogenicity test of isolate no. 3 was selected for the method description. Ten 1-month-old ginger plants (cv. Laiwu Big Ginger) were grown in plastic pots (diameter 20 cm) with sandy soil and inoculated. Ten plants were used as untreated controls. Isolate no. 3 was grown on casein hydrolysate medium (4) for 72 h and the spores were harvested in sterile distilled water. Aqueous spore suspensions of isolate no. 3 were adjusted with deionized water to 1 × 108 CFU/ml as the inoculum. The prepared inoculum was injected with a syringe into the soil around the rhizome of ginger plants. Inoculated plants were placed in the greenhouse at 24 to 26°C and assessed for rhizome rot on the 14th day after inoculation. Disease severity was recorded based on a scale in which – = no symptoms; 1 = small lesions on seedlings, no rot; 2 = seedling rot; and 3 = plant dead. Similar rhizome rot symptoms were observed after inoculation. The inoculated isolate was re-isolated from diseased rhizomes, confirming its pathogenicity. To our knowledge, this is the first report of rhizome rot of ginger caused by F. oxysporum in China. Rhizome rot of ginger caused by Fusarium spp. is well known in Asian countries such as India (2). References: (1) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. (2) V. Shanmugam et al. Biol Control. 66:1, 2013. (3) E. E. Trujillo. Diseases of Ginger (Zingiber officinale) in Hawaii, Circular 62, Hawaii Agricultural Experiment Station, University of Hawaii, December, 1964. (4) G. E. Wessman. Appl. Microbiol. 13:426, 1965.

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Bacillus pumilus, a Novel Ginger Rhizome Rot Pathogen in China

Plant Disease ◽

10.1094/pdis-12-12-1178-re ◽

2013 ◽

Vol 97 (10) ◽

pp. 1308-1315 ◽

Cited By ~ 12

Author(s):

Qin Peng ◽

Yihui Yuan ◽

Meiying Gao

Keyword(s):

Molecular Biology ◽

Bacillus Pumilus ◽

Shandong Province ◽

Gram Positive ◽

Disease Symptoms ◽

Starch Grains ◽

First Report ◽

Ginger Rhizome ◽

Parenchyma Cells ◽

Rhizome Rot

Ginger rhizome rot is a major factor limiting the yield and marketability of ginger in Shandong Province, China. In order to identify the pathogen causing ginger rhizome rot, evaluate its pathogenicity, and explore its pathogenesis, diseased ginger rhizomes and surrounding soils were collected. A gram-positive, spore-forming, rod-shaped bacterium, designated GR8, was frequently isolated from the ginger rhizome samples. The bacterium was identified as Bacillus pumilus based on physio-biochemical and molecular biology characteristics. Pathogenicity studies with GR8 showed that it could cause disease of the tested rhizomes slices and the entire rhizome when wounded but no disease occurred when the rhizome was not wounded. Preliminary pathogenicity studies demonstrated that cell-free cultures of GR8 could not cause any disease symptoms, whereas the bacterial suspensions caused severe symptoms. The pathology studies revealed that infection of GR8 could cause starch grains to shrink from normal size, and destroy the parenchyma cells by invading and propagating in them. This is the first report of B. pumilus causing ginger rhizome rot.

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First Report of Rhizome Rot Caused by Pectobacterium brasiliense on Ginger in China

Plant Disease ◽

10.1094/pdis-10-21-2324-pdn ◽

2022 ◽

Author(s):

Jinhui Wang ◽

Yuxiang Lu ◽

Wanxin Han ◽

Lijun Fu ◽

Xiaoqing Han ◽

...

Keyword(s):

16S Rdna ◽

Disease Incidence ◽

Housekeeping Genes ◽

Zingiber Officinale ◽

Soft Rot ◽

Management Options ◽

Universal Primer ◽

First Report ◽

Wide Range ◽

Rhizome Rot

In August 2020, ginger (Zingiber officinale) rhizomes (cv. Mianjiang) showing soft rot symptoms were observed in a field in Tayang Village, Fengrun District, Tangshan, Hebei Province (North China). The disease incidence in that field (15 ha in size) was more than 20%. Symptomatic rhizomes (brown and water-soaked) were surface-sterilized in 75% ethanol for 60 sec and then three successive rinses with sterile distilled water. Rhizomes were cut into pieces ca. 0.5 cm in length, and then were soaked in 500 µl 0.9% saline for 20 min. Aliquots (20 μl) of three tenfold dilutions of the tissue specimen soaking solution were plated onto the lysogeny broth (LB) medium. And LB plates were incubated at 28°C for 24 h. Five single colonies were picked from each LB plate and restreaked three times for purity. Endophytic bacteria were also isolated from asymptomatic rhizomes as control. The bacterial gDNA was extracted using the EasyPure Bacteria Genomic DNA Kit (TransGen Biotech, Beijing, China). The 16S rDNA region was amplified by PCR using the universal primer pair 27F/1492R (Weisburg et al. 1991) and sequenced. The results of BLASTN against NCBI nr of the 16S rDNA amplicons suggested that the most isolates (8/10) obtained from the rotten rhizomes belonged to the genus Pectobacterium, and few isolates (2/10) were Enterobacter spp.. Only Enterobacter spp. were isolated from asymptomatic rhizomes. Since all Pectobacterium isolates showed identical 16S rDNA sequence, thus, only two isolates were selected for further analysis. Pectobacterium isolates TS20HJ1 and TS20HJ2 (MZ853520, MZ853521) represent isolates from two plant individuals. To determine the species of the rhizome rot Pectobacterium isolates, multi-locus sequence analysis (MLSA) was performed with five housekeeping genes acnA, icdA, mdh, proA and rpoS (MZ994717-MZ994726) (Ma et al. 2007; Waleron et al. 2008), and a phylogenetic tree was reconstructed using RAxML v8.2.12 (github.com/stamatak/standard-RAxML). No sequence variation was observed at any MLSA locus between the two isolates. The result of phylogenetic analysis showed that the ginger rhizome isolates clustered with P. brasiliense type strain IBSBF1692T (Duarte et al. 2004; Nabhan et al. 2012). Ginger seedlings (cv. Mianjiang) were inoculated with the isolate TS20HJ1 by injecting 10 µl of bacterial suspensions (108 CFU·mL-1) into the rhizomes, or injected with 10 µl of 0.9% saline solution as control. The seedlings were grown at 28°C and 50% relative humidity. Ten days after inoculation, only the bacteria-inoculated rhizomes showed diseased symptoms resembling to those observed in the field. Bacterial colonies were obtained from the infected rhizomes and were identified with MLSA gene sequencing, fulfilling Koch’s postulates. P. brasiliense causes soft rot of a wide range of economically important crops (Oulghazi et al. 2021). To our knowledge, this is the first report of P. brasiliense causing rhizome rot of ginger in China. The rhizome rot caused 20-25% yield loss on average in Tangshan region in 2020, which poses a significant threat to the local ginger farming. Further research on epidemiology and disease management options is needed.

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First report of Phytophthora rot of ginger (Zingiber officinale) caused by Phytophthora citrophthora in Japan.

Japanese Journal of Phytopathology ◽

10.3186/jjphytopath.77.299 ◽

2011 ◽

Vol 77 (4) ◽

pp. 299-303

Author(s):

M. YAMAZAKI ◽

H. MATSUOKA ◽

K. YANO ◽

Y. MORITA ◽

S. UEMATSU ◽

...

Keyword(s):

Zingiber Officinale ◽

Phytophthora Citrophthora ◽

First Report ◽

Phytophthora Rot

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Draft Genome Sequence of Hydrocarbon-DegradingEnterobacter cloacaeStrain S1:CND1, Isolated from Crude Oil-Contaminated Soil from the Noonmati Oil Refinery, Guwahati, Assam, India

Genome Announcements ◽

10.1128/genomea.00367-16 ◽

2016 ◽

Vol 4 (3) ◽

Author(s):

Arghya Mukherjee ◽

Bobby Chettri ◽

James S. Langpoklakpam ◽

Arvind K. Singh ◽

Dhrubajyoti Chattopadhyay

Keyword(s):

Crude Oil ◽

Genome Sequence ◽

Contaminated Soil ◽

Draft Genome ◽

Enterobacter Cloacae ◽

Oil Refinery ◽

Draft Genome Sequence ◽

Coding Sequences ◽

First Report

We report here the 4.57-Mb draft genome sequence of hydrocarbon-degradingEnterobacter cloacaestrain S1:CND1 isolated from oil-contaminated soil in Guwahati, India. S1:CND1 contains 4,205 coding sequences and has a G+C content of 57.45%. This is the first report of the genome sequence of anE. cloacaeadapted to an oil-contaminated environment.

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First Report of a Bulb Decay of Onion by Enterobacter cloacae in Colorado

Plant Disease ◽

10.1094/pdis.2000.84.7.808b ◽

2000 ◽

Vol 84 (7) ◽

pp. 808-808

Author(s):

H. F. Schwartz ◽

K. Otto

Keyword(s):

Similarity Index ◽

Enterobacter Cloacae ◽

High Temperature Stress ◽

Dry Rot ◽

Representative Strain ◽

First Report ◽

Plastic Bags ◽

Biolog Analysis ◽

Scattered Fields ◽

Physiological Tests

Sweet Spanish onion cultivars (Allium cepa L.) in northern Colorado displayed symptoms of postharvest bulb rot during September to November of 1999. This disease appears identical to that reported from infected onions in California in 1988 and is presumably associated with high temperature stress (1). Mature, firm bulbs harvested from scattered fields in Weld County exhibited a brownish discoloration and breakdown of inner scales. Gram negative, rod-shaped, cream-colored bacteria were consistently recovered from infected bulb tissue on nutrient agar. Physiological tests showed that the bacteria utilized glucose in an oxidative and fermentative manner and were catalase positive and oxidase negative. A representative strain was identified by Microbe Inotech Laboratories (St. Louis, MO) as Enterobacter cloacae (Jordan) Hormaeche & Edwards (2) using Biolog analysis, with a similarity index of 0.81. To confirm pathogenicity, a 0.5- to 1.0-ml suspension of bacteria (108 CFU/ml sdw) was injected into firm onion bulbs (7.5 to 10.0 cm diameter). After incubation for 14 days at 22°C in closed plastic bags in the dark, bulbs were cut in half and evaluated. Tan to brown discoloration and initial dry rot, similar to that observed postharvest, was observed in inoculated bulbs. The pathogen was reisolated from six of eight bulbs inoculated with the representative strain. No discoloration or disease developed on eight control bulbs injected with water. To our knowledge, this is the first report of E. cloacae from onion grown in Colorado. References: (1) A. L. Bishop and R. M. Davis. Plant Dis. 74:692, 1990. (2) Hormaeche and Edwards. Int. J. System. Bacteriol. 30:293, 1960.

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First Report of Shoot Canker on Chestnut Caused by Diaporthe nobilis in Shandong Province of China

Plant Disease ◽

10.1094/pdis-02-18-0274-pdn ◽

2018 ◽

Vol 102 (11) ◽

pp. 2376 ◽

Cited By ~ 1

Author(s):

Q. Zhang ◽

H. Liu ◽

C. Yu ◽

C. Wang

Keyword(s):

Shandong Province ◽

First Report

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First Report of Phytopythium helicoides Causing Rhizome Rot of Asian Lotus in China

Plant Disease ◽

10.1094/pdis-07-15-0833-pdn ◽

2016 ◽

Vol 100 (2) ◽

pp. 532 ◽

Cited By ~ 7

Author(s):

X. Yin ◽

X. Z. Li ◽

J. J. Yin ◽

X. Wu

Keyword(s):

First Report ◽

Rhizome Rot

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Rhizome Rot of Zingiber officinale Rosc. and Z. mioga Rosc. by Pythium Species

Annual Report of The Kansai Plant Protection Society ◽

10.4165/kapps1958.9.0_49 ◽

1967 ◽

Vol 9 (0) ◽

pp. 49-55

Author(s):

Kiichi KATSURA ◽

Yoshiharu TANIOKA

Keyword(s):

Zingiber Officinale ◽

Pythium Species ◽

Rhizome Rot

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First Report in China of Soft Rot of Ginger Caused by Pythium aphanidermatum

Plant Disease ◽

10.1094/pdis-01-14-0094-pdn ◽

2014 ◽

Vol 98 (7) ◽

pp. 1011-1011 ◽

Cited By ~ 4

Author(s):

Y. Li ◽

L. G. Mao ◽

D. D. Yan ◽

X. M. Liu ◽

T. T. Ma ◽

...

Keyword(s):

Aerial Mycelium ◽

Zingiber Officinale ◽

Average Diameter ◽

Soft Rot ◽

Pythium Aphanidermatum ◽

Selective Medium ◽

Rrna Gene ◽

Distilled Water ◽

First Report ◽

Pythium Soft Rot

Ginger (Zingiber officinale Roscoe) is an important commercial crop planted on more than 13,000 ha annually in Anqiu city, Shandong Province, China. From 2010 to 2011, the incidence of Pythium soft rot disease on cv. Laiwu Big Ginger reached 40 to 75% in Anqiu and yield losses of up to 60% were observed. The disease symptoms included brown spots on ginger rhizomes followed by soft rot, stems and leaves above ground becoming withered and yellow, and water soaking on the collar region. The soft rot did not produce offensive odors, which is different from bacterial rots (2). Forty symptomatic rhizomes were sampled from eight farms. Martin's method (1) was used to isolate the pathogen. Ten pieces from each rhizome were washed with sterile distilled water for 30 s and plated on Martin's selective medium at 26°C in a chamber without light. Colonies grew with cottony aerial mycelium. Main hyphae were 5.7 to 9.6 μm wide. Globose sporangia consisting of terminal complexes of swollen hyphal branches were 11.4 to 18.3 μm wide. The average diameter of zoospores was 9.2 μm. The oogonia were globose and smooth, with a diameter of 21 to 33 μm. The sequences of the rRNA gene internal transcribed spacer (ITS) regions 1 and 2 and the 5.8S gene of five isolates were amplified using primers ITS1 and ITS4 (4), and the nucleotide sequence was the same as isolate No. 2, which was deposited in GenBank (Accession No. KC594034). A BLAST search showed 99% identity with Pythium aphanidermatum strain 11-R-8 (Accession No. JQ898455.1). Pathogenicity tests of five isolates were carried out in a greenhouse. Sixty plants (cv. Laiwu Big Ginger) were grown for 30 days in plastic pots (diameter 20 cm) in sandy soil (pH 5.48) and inoculated. Ten plants were used as untreated controls. Five isolates were grown on Martin's liquid medium for 72 h and the spores were harvested in sterile distilled water. Aqueous spore suspensions of the five isolates were adjusted with deionized water to 1 × 108 CFU/ml and injected with a syringe into the soil around the rhizome of the plants. Plants were then placed in the greenhouse at 24 to 26°C and assessed for rhizome rot on the 14th day after inoculation. The inoculated isolates were recovered from the diseased rhizomes, confirming their pathogenicity. To our knowledge, this is the first report of ginger Pythium soft rot caused by P. aphanidermatum in China. Ginger Pythium soft rot caused by P. myriotylum is reported in Taiwan (3). References: (1) F. N. Martin. Page 39 in: The Genus Pythium. American Phytopathological Society, St. Paul, MN, 1992. (2) E. E. Trujillo. Diseases of Ginger (Zingiber officinale) in Hawaii, Circular 62, Hawaii Agricultural Experiment Station, University of Hawaii, December 1964. (3) P. H. Wang. Lett. Appl. Microbiol. 36:116, 2003. (4) T. J. White. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

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