First report of myrothecium rhizome spot of ginger (Zingiber officinale) caused by Myrothecium verrucaria in Japan.

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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First Report of Ginger Rhizome Rot Caused by Fusarium oxysporum in China

Plant Disease ◽

10.1094/pdis-07-13-0729-pdn ◽

2014 ◽

Vol 98 (2) ◽

pp. 282-282 ◽

Cited By ~ 6

Author(s):

Y. Li ◽

L. D. Chi ◽

L. G. Mao ◽

D. D. Yan ◽

Z. F. Wu ◽

...

Keyword(s):

Fusarium Oxysporum ◽

Casein Hydrolysate ◽

Zingiber Officinale ◽

Selective Medium ◽

Shandong Province ◽

Pathogenicity Test ◽

Distilled Water ◽

Dry Rot ◽

First Report ◽

Rhizome Rot

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

Plant Disease ◽

10.1094/pdis-05-20-1108-pdn ◽

2021 ◽

Vol 105 (1) ◽

pp. 210

Author(s):

Jing Liu ◽

Zongchao Zhao ◽

Caixia Wang

Keyword(s):

Enterobacter Cloacae ◽

Zingiber Officinale ◽

Shandong Province ◽

First Report ◽

Rhizome Rot

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First Report of Myrothecium verrucaria Causing Leaf Spot of Maize in Pakistan

Plant Disease ◽

10.1094/pdis-09-16-1375-pdn ◽

2017 ◽

Vol 101 (4) ◽

pp. 633 ◽

Cited By ~ 3

Author(s):

M. Saira ◽

A. Rehman ◽

M. L. Gleason ◽

M. W. Alam ◽

S. Muhammad ◽

...

Keyword(s):

Leaf Spot ◽

First Report ◽

Myrothecium Verrucaria

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First Report of Myrothecium verrucaria from Muskmelon Seeds

Plant Disease ◽

10.1094/pdis.1999.83.6.589c ◽

1999 ◽

Vol 83 (6) ◽

pp. 589-589 ◽

Cited By ~ 6

Author(s):

A. Belisario ◽

E. Forti ◽

L. Corazza ◽

H. A. van Kesteren

Keyword(s):

Root Rot ◽

Cucumis Melo ◽

Potato Dextrose Agar ◽

Main Root ◽

Differential Host ◽

First Report ◽

Myrothecium Verrucaria ◽

Petri Dishes ◽

Melon Seeds ◽

Cucumis Melo L

Myrothecium verrucaria (Albertini & Schwein.) Ditmar:Fr. was isolated from muskmelon (Cucumis melo L.) seeds of Charentais-T, a culti var used as a differential host with no resistance to Fusarium oxysporum f. sp. melonis races. A white floccose mycelial mat developed on melon seeds during incubation on moist blotters. Mycelia were mass transferred from melon seeds onto potato dextrose agar (PDA) medium. At 25°C in the dark, a mycelial mat with characteristic annelations of greenish-black sporodochia, without setae, was produced. Conidia (2 to 3 × 6 to 10 μm) were lemon shaped, with a typical conical mucous appendage at one end, which was visible with Loeffer's flagella stain (1). Based on these characteristics, the fungus was identified as M. verrucaria. For pathogenicity studies, surface sterilized seeds of C. melo cv. Charentais-T were coated with M. verrucaria conidia by gently rubbing the seeds on sporodochia produced on 15-day-old cultures on PDA. Once coated, seeds were plated onto water agar and on sterile moist blotters in 9-cm-diameter petri dishes. Plates were incubated at 28°C in the dark. Five seeds per plate and three plates per experiment were used. Experiments were replicated three times. Control seeds were plated without coating. After 7 days, on water agar, 90% of melon seeds failed to germinate while the remaining 10% produced young seedlings that died from root rot and necrotic lesions on the hypocotyl. After 12 days on moist blotters, 100% of the melon seedlings died, showing necrotic lesions on the hypocotyl and on the main root. The pathogen was reisolated from symptomatic melon seedlings. All control seeds germinated and grew into healthy seedlings. M. verrucaria, known to be a seed-borne pathogen, has been isolated from soil and plants worldwide (2). This is the first report of M. verrucaria pathogen on muskmelon. This fungus is not a serious concern when seeds are dressed with fungicides. References: (1) K. V. A. Thompson and S. C. Simmens. Nature. 193:196, 1962. (2) S.-M. Yang and S. C. Jong. Plant Dis. 79:994, 1995.

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First Report of Meloidogyne enterolobii on Ginger (Zingiber officinale) in China

Plant Disease ◽

10.1094/pdis-09-17-1477-pdn ◽

2018 ◽

Vol 102 (3) ◽

pp. 684-684

Author(s):

S. Xiao ◽

X. Y. Hou ◽

M. Cheng ◽

M. X. Deng ◽

X. Cheng ◽

...

Keyword(s):

Zingiber Officinale ◽

First Report ◽

Meloidogyne Enterolobii

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First Report of Aspergillus niger as a Plant Pathogen on Zingiber officinale from India

Plant Disease ◽

10.1094/pdis-92-9-1368c ◽

2008 ◽

Vol 92 (9) ◽

pp. 1368-1368 ◽

Cited By ~ 3

Author(s):

N. V. Pawar ◽

V. B. Patil ◽

S. S. Kamble ◽

G. B. Dixit

Keyword(s):

Aspergillus Niger ◽

16S Rrna ◽

Zingiber Officinale ◽

Leaf Spot Disease ◽

Dense Layer ◽

Distilled Water ◽

Conidial Suspension ◽

Major Area ◽

First Report ◽

Molecular Approaches

Zingiber officinale Rosc., belonging to the Zingiberaceae family, is medicinally important. It is commonly known as ginger and has been extensively cultivated for many centuries for use as a spice and traditional medicine in India. During a survey in September of 2007, leaves of Z. officinale showed a necrotic leaf spot disease on a plant growing in Kolhapur, India. Symptoms of the disease appeared as small (10 to 15 mm), rectangular to irregular, yellow spots on the leaves that covered a major area of the leaf when severe. The infection caused defoliation. Symptomatic leaves were collected and isolations from infected leaves were made on Czapek's Dox agar supplemented with streptomycin sulfate (30 mg/l). Plates were incubated at 28 to 30°C for 6 to 7 days. The fungal colonies were colorless to pale on the reverse side and covered with a dense layer of dark brown-to-black conidial heads. Conidia were globose to subglobose (3.5 to 5.0 μm in diameter), dark brown to black, and rough walled. 16S rRNA of isolates was amplified and sequenced (EMBL Accession No. AM941157) and compared with sequences of known Aspergillus species obtained from GenBank. The closest matches (99% identity) were with A. niger. On the basis of morphological and molecular approaches, the pathogen was confirmed as A. niger. Of five isolates, AN-5 was used for pathogenicity study. Koch's postulates were satisfied after reisolating the fungus from leaves inoculated with a conidial suspension that showed symptoms (6 days after inoculation) similar to the lesions observed on the leaves collected from Z. officinale. The tests were repeated three times in the greenhouse. Healthy, potted Z. officinale plants were grown in isolation after artificial inoculation with a suspension of spores (10,000 conidia per ml), which was prepared in 100 ml of sterile distilled water and then sprayed on the abaxial and adaxial surface of leaves. Noninoculated plants served as controls. These results confirmed the pathogenicity of A. niger on Z. officinale. To our knowledge, this is the first report of A. niger causing a disease on ginger (1). Reference: (1) G. N. Dake. J. Spices Aromatic Crops. 4:40, 1995.

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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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