Black spot disease of alstroemeria caused by <Emphasis Type="Italic">Alternaria alstroemeriae</Emphasis> in Japan

A black spot disease on cultivated alstroemeria was found in Nagano Prefecture, Japan, in January 2008. The causal fungus isolated from the diseased plants was morphologically identified as Alternaria alstroemeriae E.G. Simmons & C.F. Hill. An inoculation test with the isolated fungus demonstrated that the disease is caused by this species. This is the first report of black spot on alstroemeria (kokuhan-byo, in Japanese) caused by A. alstroemeriae in Japan.     

Corynespora blight of sweet pepper (<Emphasis Type="Italic">Capsicum annuum</Emphasis>) caused by <Emphasis Type="Italic">Corynespora cassiicola</Emphasis> (Berk. &; Curt.) Wei

In 2004, Corynesopra cassiicola was isolated from dark brown spots on leaves and fruits and from black blights on stems of sweet pepper plants in Kochi Prefecture, Japan. The isolated fungus was then used to inoculate sweet pepper plants and subsequently reisolated from the plants with dark brown spots and black blights, showing that C. cassiicola is a new pathogen causing Corynespora blight on sweet pepper plants. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases as accession numbers AB366649 (TS-C11), AB366650 (TS-C21), AB366651 (TI-C32) and AB366652 (TI-C51)     

Anthracnose of salt-wort (<Emphasis Type="Italic">Salsola komarovii</Emphasis>) caused by <Emphasis Type="Italic">Colletotrichum truncatum</Emphasis>

In July 2006, black rot was observed on the leaves of 4-leaf-stage seedlings of salt-wort (Salsola komarovii) in Yamagata Prefecture, Japan. We isolated two single-conidial isolates from the diseased leaves. Although colony appearance of the isolates was different from that of each other, both isolates were identified as Colletotrichum truncatum by morphology and molecular similarity. After inoculation of healthy salt-wort plants with the isolates, the isolates were reisolated from symptomatic plants. We thus propose a new disease, anthracnose of salt-wort.     

Successful Back-inoculation Confirms the Role of Black Currant Reversion Associated Virus as the Causal Agent of Reversion Disease

Reversion is the most wide-spread and serious virus-like disease infecting black currant but the causal agent of the disease has not been described. Recently, we have isolated a new nepovirus from reversion-infected black currant and by using immunocapture-RT-PCR detection, we have shown that the virus is consistently associated with reversion disease (Lemmetty et al., Phytopathology 87: 404–413, 1997). These data suggested that the virus, tentatively called black currant reversion associated virus (BRAV), could be the causal agent of reversion disease. Here we report that the isolated virus was successfully inoculated back to healthy black currant plants by slash inoculation of in vitro propagated young recipient plants. Vein pattern symptoms identical or very similar to the reported early symptoms of reversion disease were produced in the virus-infected plants. Using immunocapture-RT-PCR, the virus was again detected from symptomatic but not from inoculated symptomless plants or from the mock-inoculated or uninoculated controls. Production of the acute reversion symptoms demonstrates that BRAV is the causal agent of reversion disease, and we therefore propose that the virus be named black currant reversion virus, abbreviated BRV.     

First report of <Emphasis Type="Italic">Impatiens necrotic spot virus</Emphasis> infecting chrysanthemum (<Emphasis Type="Italic">Chrysanthemum morifolium</Emphasis>) in Japan

In 2009, chlorotic mottle and necrosis were observed on chrysanthemums (cv. Jimba) in Aomori Prefecture, Japan. A virus was isolated from the chrysanthemum plants by serial local-lesion transfer. The symptoms exhibited by the test plants, the particle morphology, the features of the protein and the potential for transmission by thrips were similar to those for Impatiens necrotic spot virus (INSV). The partial nucleotide sequences of the nucleocapsid protein gene and the 3′-untranslated sequence of the S RNA shared 99% identity with that of an INSV isolate. This report is the first of INSV infection of chrysanthemums in Japan.     

Cycas necrotic stunt virus isolated from gladiolus plants in Japan

An undescribed spherical virus ca. 30 nm in diameter was isolated from gladiolus (Gladiolus spp.) plants in Japan. The virus had a moderate host range within eight families. Purified virus preparations contained two large RNA components and one coat protein with mobility similar to Cycas necrotic stunt virus (CNSV) from cycas (Cycas revolute). The virus was serologically closely related to CNSV. Its nucleotide sequence of the coat protein gene had 89% common identity with that of CNSV. These results indicated that the virus isolated from gladiolus is a new strain of CNSV. The nucleotide sequence data reported are available in the DDBJ/EMBL/Gen Bank databases under the accession number AB237656.     

First report of a <Emphasis Type="Italic">Grapevine Algerian latent virus</Emphasis> disease on statice plants (<Emphasis Type="Italic">Limonium sinuatum</Emphasis>) in Japan

A viral disease was found in Nagano Prefecture, Japan, on statice (Limonium sinuatum) with chlorotic leaf spot, necrotic stunt, and dwarfing. Spherical virus particles 30 nm in diameter were isolated from infected plants and statice seedlings and caused identical symptoms 4 weeks after mechanical inoculation. Nucleotide and deduced amino acid sequences of the coat protein showed 98% and 98.7% identities with those of Grapevine Algerian latent virus (GALV) nipplefruit strain. This is the first report in Japan of a viral disease on statice caused by GALV. The nucleotide sequence data reported here are available in the DDBJ/EMBL/GenBank databases under accession AB461854.     

Biology of Southern rice black‐streaked dwarf virus: a novel fijivirus emerging in East Asia

Southern rice black‐streaked dwarf virus (SRBSDV) was first reported in southern China in 2001 and causes a striking disease on rice and maize that leads to serious yield losses in several East Asian countries, such as China, Vietnam and Japan. A large research effort has been directed to understanding the virus and controlling the disease. Its geographic distribution, disease cycle via its insect vector, genome organization, relationship with host plants, and epidemiology are summarized in this review and the important role played by the vector, the white‐backed planthopper (Sogatella furcifera), is emphasized. Countermeasures to control the disease that have been developed and applied include molecular detection for precise forecasting, chemical, physical, and ecological pest management. There is widespread insecticide resistance in the vector population but it is hoped that current efforts to develop rice cultivars resistant to the virus will eventually provide effective and cost‐effective control.     

Blue mold of tomato caused by <Emphasis Type="Italic">Penicillium oxalicum</Emphasis> in Japan

In 2006, stem rot and blue-green crusty lesions were found on the stems of tomato plants in Chiba Prefecture, Japan. Penicillium oxalicum was isolated repeatedly from the diseased plants. The causal fungus reproduced natural symptoms after artificial inoculation of tomato plants and was re-isolated from symptomatic plant tissue. P. oxalicum is a new pathogen that causes blue mold on tomato plants in Japan.     

Characterization of Erwinia sp. causing black rot of papaya (Carica papaya) first recorded in Okinawa Main Island,Japan

Since 2002, papaya black rot has been spreading over several islands of Okinawa Prefecture, Japan. To devise a prevention strategy for the disease, microbiological research on the pathogen was conducted. Twelve strains were isolated from papaya infected with black rot showing symptoms such as water-soaked lesions on stems and petioles, black spots on fruits, and rotted leaves turning yellow with necrotic spots. Through Koch's postulates, we confirmed that the isolated strains caused papaya black rot. Bacteriological assays showed that the strains have characteristics different from the type strains of Erwinia mallotivora, E. papayae, and E. psidii. Moreover, 16S rDNA sequence similarity searches showed that the isolated strains had less than 98.6% similarity with type strains. Additionally, phylogenetic analysis of 16S rDNA sequences suggested that the isolated strains were possibly a novel species belonging to the genus Erwinia, as the strains formed an independent cluster and had low sequence similarity with the type strains. Earlier studies indicated that papaya black rot is caused by E. cypripedii. Therefore, we propose to add the Erwinia sp. isolated in this study to the list of papaya black rot pathogens.     

New Leaf Spot Disease of Cymbidium Species Caused by Fusarium subglutinans and Fusarium proliferatum

Fusarium species were consistently isolated from yellow, swollen spots with reddishbrown centers and small black spots on leaves of Cymbidium plants in the greenhouse. Fusarium subglutinans caused the yellow spots and Fusarium proliferatum caused either the yellow or the black spots. We propose the name “yellow spot” for the new disease. To denote differences in their pathogenicity to orchid plants, we designate the population causing yellow spot as race Y and that causing black spot as race B of F. proliferatum. Received 29 October 1999/ Accepted in revised form 10 March 2000     

Black band of Jew’s marrow caused by <Emphasis Type="Italic">Lasiodiplodia theobromae</Emphasis>

Stem rot and wilt of Jew’s marrow (nalta jute, Corchorus olitorius) were found on Is. Okinawa, Okinawa Prefecture, Japan, in March 2000. An anamorphic fungus, Lasiodiplodia theobromae was isolated repeatedly from the diseased plants and demonstrated to cause the disease. We coined the Japanese name “kurogare-byô” of Jew’s marrow for the present disease because it was new to Japan, although it had already been reported in India and Bangladesh as black band of the plant.     

Myrothecium leaf spot of mulberry caused by Myrothecium verrucaria

A fungus that formed white colonies with greenish black spore masses was isolated from diseased mulberry leaves in Gunma Prefecture, Japan, in 1995, 1999, and 2000. It was pathogenic to mulberry. The fungus was identified with Myrothecium verrucaria. It has been added to the list of pathogens that cause Myrothecium leaf spot of mulberry and is identified for the first time as a plant pathogen in Japan.     

Black leaf spot and circular leaf spot of <Emphasis Type="Italic">Farfugium japonicum</Emphasis> (L.) Kitamura caused by <Emphasis Type="Italic">Phoma</Emphasis> spp.

In May 1998 and 1999, two types of leaf spot (black type and brown type) caused by Phoma spp. were found on Farfugium japonicum in Tokyo and in Gunma Prefecture, Japan. The fungus isolated from black-type lesions caused only black-type lesions, and the fungus from brown-type lesions caused only brown-type lesions. We propose to name these diseases black leaf spot of F. japonicum (kokuhan-byo in Japanese) for the disease with black lesions and circular leaf spot of F. japonicum (rinmon-byo in Japanese) for the disease with brown lesions. This is the first report on leaf diseases of F. japonicum caused by Phoma spp.     

Evolutionary Characterization of Two Lily Isolates of Cucumber mosaic virus Isolated in Japan and Korea

We analyzed the evolutionary histories of two lily strains of Cucumber mosaic virus (CMV) isolated in Japan and Korea (HL- and Ly2-CMVs). They share common biological characteristics in that their host ranges are very restricted perhaps from a unique adaptation to lily plants. Although HL and Ly2 were isolated independently from different lily species in separate countries, their RNA3 sequences had a very high sequence similarity (97%). The evolutionary relationships between the two isolates were characterized by comparing their phylogenetic trees for the 3a and CP genes. The two lily CMVs always formed a distinct cluster within subgroup IB in 3a, but within IA in CP. Together, the phylogenetic tree topology and the sequence identity between the two lily CMVs suggest that they evolved from a common progenitor. Received 5 November 2001/ Accepted in revised form 11 January 2002     

<Emphasis Type="Italic">Turnip yellow mosaic virus</Emphasis> isolated from Chinese cabbage in Japan

A virus that caused a distinct yellow mosaic was isolated in Okayama, Japan from Chinese cabbage (Brassica rapa L., Pekinensis group). The virus, with spherical particles ca. 28 nm in diameter, was mechanically transmissible only to cruciferous species. From the host range, characteristic morphology of virus particles, serology and sequence analysis of coat protein gene, the causal virus was identified as Turnip yellow mosaic virus (TYMV). Seed transmission of TYMV at 0–2.2% in Chinese cabbage was confirmed. This report is the first of TYMV from Chinese cabbage and in Japan. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases as accessions AB358971 and AB358972.     

Characterization of Grapevine Algerian latent virus isolated from nipplefruit (Solanum mammosum) in Japan

Alfalfa mosaic virus (AMV), Cucumber mosaic virus (CMV), Potato virus Y (PVY), Tomato bushy stunt virus nipplefruit strain (TBSV-Nf), and an unknown spherical virus were isolated from nipplefruit (Solanum mammosum) cultivated in Chiba Prefecture, Japan. The spherical virus was identified as Grapevine Algerian latent virus nipplefruit strain (GALV-Nf) from the genus Tombusvirus, based on its physical properties, serological relationships, and analysis of genomic RNA. The genomic RNA of GALV-Nf is 4731 nucleotides long and encodes five open reading frames as well as those of other tombusviruses. Nipplefruit infected with GALV-Nf had severe stunting, leaf deformation, and clear mosaic symptoms. This is the first report of an isolation of GALV in Japan. An erratum to this article is available at .     

Cucumber mosaic virus isolated from Aconitum spp. in Japan

Viruses were isolated from leaves of plants of Aconitum species with symptoms such as mottling and yellowing in Hokkaido and Gunma prefectures in Japan. These viruses were identified as Cucumber mosaic virus (subgroup II) based on particle morphology, host range, aphid transmission, and serology.