Addition of <Emphasis Type="Italic">Pestalotiopsis </Emphasis>spp. to leaf spot pathogens of Japanese persimmon

 In June 1996, a leaf spot disease widely occurred in Japanese persimmon (Diospyros kaki) orchards in Tottori Prefecture, Japan. The main diagnostic symptom was ring spot on the leaves and calyxes of young fruits; in severe cases, lesions developed on more than half of the area of the leaf, resulting in early defoliation. Based on morphological and pathological studies of the isolated fungi, it was shown that Pestalotiopsis longiseta, P. glandicola, P. acaciae, and P. crassiuscula were responsible for the diseases. These fungi, except P. longiseta, were found to be new pathogens of the disease. Received: May 20, 2002 / Accepted: July 25, 2002     

Induced systemic resistance of Chinese cabbage to bacterial leaf spot and <Emphasis Type="Italic">Alternaria </Emphasis>leaf spot by the root endophytic fungus, <Emphasis Type="Italic">Heteroconium chaetospira</Emphasis>

 The root endophytic fungus Heteroconium chaetospira isolate OGR-3 was tested for its ability to induce systemic resistance in Chinese cabbage against bacterial leaf spot caused by Pseudomonas syringae pv. maculicola and Alternaria leaf spot caused by Alternaria brassicae of the foliar diseases. Chinese cabbage seedlings planted in soil infested with an isolate of H. chaetospira were incubated in a growth chamber for 32 days. The first to fourth true leaves of the seedlings were challenge-inoculated with P. syringae pv. maculicola or A. brassicae. Chinese cabbage planted in soil infested with H. chaetospira showed significant decreases in the number of lesions of bacterial leaf spot or Alternaria leaf spot when compared to the control plants not treated with H. chaetospira. The results indicated that colonization of roots by H. chaetospira could induce systemic resistance in Chinese cabbage and reduce the incidence of bacterial leaf spot and Alternaria leaf spot. Received: April 24, 2002 / Accepted: August 9, 2002     

The occurrence of coral spot of Japanese persimmon caused by <Emphasis Type="Italic">Nectria cinnabarina</Emphasis> (Tode: Fries) Fries

A twig canker disease of Japanese persimmon with characteristic coral spots was found in Tottori Prefecture, Japan. The causal fungus was identified as Nectria cinnabarina, which causes coral spot disease on many host plants. This is the first report of the disease caused by N. cinnabarina on Japanese persimmon in Japan.     

Race 3, a new race of<Emphasis Type="Italic"> Fusarium oxysporum</Emphasis> f. sp. <Emphasis Type="Italic">lactucae </Emphasis>determined by a differential system with commercial cultivars

 Pathogenic variation among 26 Japanese isolates of Fusarium oxysporum f. sp. lactucae (FOL) was tested using 21 lettuce cultivars to select commercial lettuce cultivars as race differential indicators. Cultivar Costa Rica No. 4 was resistant to race 1 but susceptible to race 2, consistent with the conventional standard differential line VP1010. Cultivar Banchu Red Fire was susceptible to race 1 but resistant to race 2, which showed an opposite type of reaction as another differential line VP1013. Cultivar Patriot was susceptible to both races. The resistance reactions of the three cultivars under field conditions were identical with that observed in the seedlings. Thus cv. Costa Rica No. 4 and cv. Banchu Red Fire can be used as differential hosts to identify pathogenic races of FOL. This differential system showed that all FOL isolates obtained from diseased butterhead lettuce in Fukuoka, Japan were new races (i.e., pathogenic to three cultivars). We propose that the new race be designated race 3. Isolates of FOL, the pathogen of Fusarium wilt in lettuce, obtained from California showed the same reaction as that of race 1. Furthermore, the Japanese isolate SB1-1 (race 1) and California isolate HL-2 belonged to the same vegetative compatibility group. Our results suggest that both of the fungi are the same forma specialis. Received: March 25, 2002 / Accepted: August 26, 2002     

Aloe ring spot,a new disease of aloe caused by <Emphasis Type="Italic">Haematonectria haematococca</Emphasis> (Berk. &; Broome) Samuels &; Nirenberg (anamorph: <Emphasis Type="Italic">Fusarium</Emphasis> sp.)

A ring spot disease of Aloe vera was found on leaves of potted seedlings of Aloe vera in Hachijojima and Chichijima Islands, Tokyo. From tissue of ring spot lesions, a fungus producing Fusarium-type conidia was consistently isolated. After 1 month, reddish perithecia of nectriaceous fungus had formed on the colonies of this isolate on PDA. These nectriaceous and Fusarium fungi were identified as Haematonectria haematococca and Fusarium sp., respectively. From a single ascospore isolation, the former was confirmed to be the teleomorph of the Fusarium sp. Typical ring spot lesions were reproduced by artificial inoculations using single ascospore and single conidium isolates. Inoculations of five species of genus Aloe revealed that they were highly susceptible except for A. arborescens. This is the first report of a disease on Aloe caused by H. haematococca (anamorph: Fusarium sp.) in Japan, and it was named aloe ring spot.     

Alternaria Leaf Spot on Mealycup Sage (<Emphasis Type="Italic">Salvia farinacea </Emphasis>Benth.) Caused by <Emphasis Type="Italic">Alternaria alternata </Emphasis>(Fr.) Keissler

In June 1995, a disease causing round to irregular-shaped, water-soaked, brown to blackish brown spots on mealycup sage (Salvia farinacea Benth.) was found in Atsugi-shi, Kanagawa Prefecture, Japan. The symptoms were seen only on leaves, not on neither flower petals or stems. The disease was also found in Setagaya-ku, Tokyo, Memambetsu-cho, Hokkaido and Shimoda-shi and Matsuzaki-cho, Shizuoka. An Alternaria sp. was frequently isolated from these diseased plants. The isolates were severely pathogenic to mealycup sage and caused lesions on the inoculated leaves. The isolates were also weakly pathogenic on scarlet sage (S. splendens Sellow ex Roem. and Schult.) but not on any other Labiatae plants tested. Based on morphological characteristics, such as size of conidia, chain number, and the short beak on conidia, the causal fungus was identified as Alternaria alternata (Fr.) Keissler. This report is the first on a mealycup sage disease caused by A. alternata. Because the symptom was restricted to the leaf, the common name of Alternaria leaf spot was proposed. Received 30 August 2002/ Accepted in revised form 18 November 2002     

New race of <Emphasis Type="Italic">Phytophthora vignae</Emphasis> f. sp. <Emphasis Type="Italic">adzukicola</Emphasis>, the causal agent of Phytophthora stem rot of the adzuki bean

 A new race of Phytophthora vignae f. sp. adzukicola, designated race 4, is reported from central and western Hokkaido, Japan. The isolates obtained from diseased plants of a new cultivar, cv. Syumari, which is resistant to races 1, 2, and 3, were determined to be a new race by the pathogenic reaction on a set of differential adzuki bean cultivars (cv. Erimo-shozu, cv. Kotobuki-shozu, cv. Noto-shozu, cv. Urasa-shimane, and cv. Syumari). Received: March 7, 2002 / Accepted: August 13, 2002     

Fruit spot of sweet lime (<Emphasis Type="Italic">Citrus limetta</Emphasis>) caused by <Emphasis Type="Italic">Septoria</Emphasis> sp. in Peru

In 2002, a severe fruit spot of sweet lime (Citrus limetta) was observed in Piura and Lambayeque provinces in northern Peru. Affected fruits showed large oval and sunken lesions, often surrounded by chlorotic haloes. Septoria sp. was isolated from affected fruits. Sweet lime isolates showed larger pycnidia and pycnidiospores than those of Septoria spp. previously described on citrus. In addition, phylogenetic analysis of the ITS sequences clearly separated the sweet lime isolates from S. citri and S. citricola. Isolates were pathogenic to detached sweet lime fruits and the fungus was isolated from lesions on inoculated fruits.     

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.     

Cloning and characterization of pea apyrases: involvement of <Emphasis Type="Italic">PsAPY1 </Emphasis>in response to signal molecules from the pea pathogen <Emphasis Type="Italic">Mycosphaerella pinodes</Emphasis>

 Two nucleoside triphosphatase (NTPase) cDNA clones were isolated from a cDNA library of Pisum sativum L., cv. Midoriusui. The genes encoding the cDNAs were designated PsAPY1 and PsAPY2. PsAPY1 included the N-terminal amino acid sequence of an NTPase bound to pea cell wall. The phylogenic analysis indicated that PsAPY1 belongs to an NTPase subfamily responsive to environmental stimuli and that PsAPY2 belongs to a discrete subfamily, the physiological role of which is almost unknown. The adenosine triphosphatase activity of recombinant PsAPY1 was regulated by an elicitor and a suppressor from the pea pathogen Mycosphaerella pinodes. Based on these findings, we discuss the role of NTPases in response to biological stresses. Received: May 27, 2002 / Accepted: July 31, 2002     

Molecular Characterization of <Emphasis Type="Italic">Bean yellow mosaic virus </Emphasis>from Vegetatively Propagated Dwarf <Emphasis Type="Italic">Gentiana </Emphasis>Plants

The causative virus (isolate No. 4) of gentian (Gentiana spp.) mosaic, which had been identified previously as Clover yellow vein virus (C1YVV) on the basis of host range and serological reactions, was re-identified as Bean yellow mosaic virus (BYMV) on the basis of the nucleotide sequences of the gene for the coat protein (CP) and the 3′-noncoding region, as well as the predicted amino acid sequence of CP. Received 16 April 2002/ Accepted in revised form 19 June 2002     

<Emphasis Type="Italic">Helicobasidium mompa</Emphasis> isolates from sweet potato in continuous monoculture fields

 Isolates of the violet root rot fungus Helicobasidium mompa were collected from herbaceous and tree plants. Their host preference was studied by inoculation experiments using carrots, sweet potatoes, and apple stocks. It was found that sweet potato isolates from Kyushu produced infection cushions on carrots and sweet potatoes but not on apple stocks. Other isolates did not show host preference. Sweet potato isolates were also characterized by ready hyphal mass (sclerotium) production. They were thought to have adapted to the habitat with high disturbance by annual tillage. Received: July 15, 2002 / Accepted: September 26, 2002     

Fruit rot of Strawberry pear (pitaya) caused by <Emphasis Type="Italic">Bipolaris cactivora</Emphasis>

Strawberry pear (pitahaya, pitaya) [Hylocereus undatus (Haw.) Britt. and Rose] postharvest fruit rot was found at an agricultural products store in Itoman city, Okinawa Prefecture in 2006. The symptoms included depressed, water-soaked lesions with olive to black powdery spots coalescing into a soft rot. The causal fungus was identified as Bipolaris cactivora (Petrak) Alcorn. This is the first report of strawberry pear fruit rot caused by B. cactivora.     

Suppression of Fusarium wilt of spinach with hypovirulent binucleate <Emphasis Type="Italic">Rhizoctonia</Emphasis>

 Four isolates of hypovirulent binucleate Rhizoctonia (HBNR) were evaluated for their ability to control Fusarium wilt of spinach (FWS) caused by Fusarium oxysporum f. sp. spinaciae (FOS). Fourteen-day-old spinach seedlings grown in paper pots with HBNR-amended soil (1% w/w ground barley grain inoculum) were transferred to artificially pathogen-infested soil. Treatments with HBNR isolates significantly (P = 0.05) reduced disease and discoloration severity by 56%–100% and 52%–100%, respectively. The numbers of colony-forming units of FOS per gram fresh weight in petioles or roots were reduced significantly (P = 0.01) in the plants treated with HBNR. HBNR isolates were well reisolated from the roots inside paper pots where they were inoculated, whereas inconsistent colonization of HBNR was recorded from the roots outside paper pots where only pathogen was inoculated. Root extracts from HBNR-treated and pathogen-challenged plants significantly inhibited germination and germling length of FOS. The fresh weight of spinach leaves in the HBNR-treated plants increased significantly (P = 0.01), as much as 53%–63%, over the untreated and pathogen-challenged plants. This is the first report of biocontrol of FWS by HBNR. Received: July 18, 2002 / Accepted: October 22, 2002 Acknowledgments We are grateful to Dr. Komada for providing nonpathogenic Fusarium F13. The senior author (A.M.) thanks the Ministry of Education, Culture, Sports, Science, and Technology (Monbukagakusho) Japan, for financial assistance.     

First report of leaf blight disease of <Emphasis Type="Italic">Gloriosa superba</Emphasis> L. caused by <Emphasis Type="Italic">Alternaria alternata</Emphasis> (Fr.) Keissler in India

Leaf blight disease was found on Gloriosa superba L. (Liliaceae), an endangered, herbaceous, perennial, climbing lily that produces colchicine, in West Bengal, India in 2004. Small brownish spots on leaves developed into concentric rings, which eventually darkened and coalesced to blight the entire leaf. The causal fungus was morphologically identified as Alternaria alternata (Fr.) Keissler. This is the first record of A. alternata on G. superba.     

A novel pathosystem to study the interactions between <Emphasis Type="Italic">Lotus japonicus</Emphasis> and <Emphasis Type="Italic">Fusarium solani</Emphasis>

A wilt disease of the model legume Lotus japonicus was observed in a greenhouse in Tokyo, Japan in May 2004. Roots of diseased plants were rotted and dark brown with lesions spreading to lower stems and leaves, resulting in rapid plant death. The causal agent was identified as Fusarium solani based on the morphology. Sequence analysis of rDNA supported the identification. Inoculation of roots of healthy plants with conidia reproduced characteristic disease symptoms, and F. solani was reisolated from lesions, satisfying Koch’s postulates. The isolate also caused chlorotic to necrotic lesions on leaves of healthy plants after wound-inoculation. Infection by F. solani of leaves of L. japonicus was confirmed histologically. Mycelia were observed in the intercellular spaces of parenchymatous tissues in the lesion area and the surrounding tissues. This is the first report of fungal disease on L. japonicus satisfying Koch’s postulates. We named it “Fusarium root rot of L. japonicus” as a new disease. The compatibility of L. japonicus and F. solani is expected to form a novel pathosystem for studying interactions between legumes and fungal pathogens. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB258993 and AB258994.     

Long-term storage and survival structure of three species of <Emphasis Type="Italic">Phytophthora </Emphasis>in water

 Cultures of Phytophthora cinnamomi, P. parasitica, and P. palmivora remained viable in water at room temperature for periods ranging from 6 to 23 years. The colonies that developed from the stored cultures were thin-walled and spherical, ranging from 19.2 to 30.0 μm in diameter. The survival structures are thought to be small chlamydospores produced in the absence of adequate nutrition and aeration. Received: October 7, 2002 / Accepted: January 8, 2003 Acknowledgment I thank Dr. Michael L. Parsons for assistance in preparing the photograph.