Didymella gigantis sp. nov. Causing Leaf Spot in Korean Angelica

During a disease survey in October 2019, leaf spot symptoms with a yellow halo were observed on Korean angelica (Anglica gigas) plants grown in fields in Pyeongchang, Gangwon Province, Korea. Incidence of diseased leaves of the plants in the investigated fields ranged from 10% to 60%. Morphological and cultural characteristics of two single-spore isolates from the leaf lesions indicated that they belonged to the genus Didymella. Molecular phylogenetic analyses using combined sequences of LSU, ITS, TUB2, and RPB2 regions showed distinct clustering of the isolates from other Didymella species. In addition, the morphological and cultural characteristics of the isolates were somewhat different from those of closely related Didymella spp. Therefore, the novelty of the isolates was proved based on the investigations. Pathogenicity of the novel Didymella species isolates was confirmed on leaves of Korean angelica plants via artificial inoculation. This study reveals that Didymella gigantis sp. nov.causes leaf spot in Korean angelica.

Didymella acutilobae sp. nov. Causing Leaf Spot and Stem Rot in Angelica acutiloba

During disease surveys of Angelica acutiloba plants in Korea, leaf spot symptoms were observed in a field in Andong in July 2019, and stem rot symptoms in vinyl greenhouses in Yangpyeong in April 2020. Incidence of leaf spot and stem rot of the plants ranged from 10 to 20% and 5 to 30%, respectively. Morphological and cultural characteristics of fungal iso lates from the leaf spot and stem rot symptoms fitted into those of the genus Phoma.Molecular phylogenetic analyses of two single-spore isolates from the symptoms using con catenated sequences of LSU, ITS, TUB2, and RPB2 genes authenticated an independent clus ter from other Didymella (anamorph: Phoma) species. Moreover, the isolates showed different morphological and cultural characteristics in comparison to closely related Didymella species. These discoveries confirmed the novelty of the isolates. Pathogenicity of the novel Didymella species isolates was substantiated on leaves and stems of A. acutiloba through artificial inocu lation. Thus, this study reveals that Didymella acutilobae sp. nov. causes leaf spot and stem rot in Angelica acutiloba.

Occurrence of Violet Root Rot on Membranous Milk Vetch Caused by Helicobasidium mompa in Korea

Severe violet root rot occurred in a field of membranous milk vetch in Bonghwa, Korea, in October 2010. Two fungal isolates from the diseased plants were identified as Helicobasidium mompa based on their morphological, cultural, and molecular characteristics. This is the first report that H. mompa causes violet root rot on membranous milk vetch in Korea.

Tectella patellaris from Korea

One rare and interesting species collected from Gyeryong-san, Chungnam Province is described and illustrated in detail. The species "Tectella patellaris (Fr.) Murr." and genus "Tectella Earle" is a first record for Korean fungal flora. Specimens cited here have been deposited in the Herbarium Conservation Center of National Academy of Agricultural Sciences.

Occurrence of Clubroot on Shepherd's-purse Caused by Plasmodiophora brassicae

Clubroot symptoms were frequently observed on roots of shepherd's-purse (Capsella bursa-pastoris) grown in a field in Nonsan, Chungnam province, Korea in March, 2009. Many resting spores were found in the cells of the root gall tissues collected from the field. The clubroot pathogen was identified as Plasmodiophora brassicae based on its morphological and pathological characteristics. This is the first report that P. brassicae causes clubroot of shepherd's-purse in Korea.

Identification of Calonectria colhounii Associated with Basal Stem Rot on Blueberry Seedlings Imported from the United States of America

Basal stem rot symptoms were found on blueberry seedlings imported from the United States of America in 2008. The fungus obtained from the diseased seedlings was identified as Calonectria colhounii based on morphological and molecular characteristics. The consignments of the blueberry seedlings infected with C. colhounii were destroyed to prevent introduction of the fungus to Korea.

Leaf Spot of Yam Caused by Pseudophloeosporella dioscoreae in Korea

Leaf spot symptoms were frequently observed on yam plants grown in the Yeoju area in Korea during a disease survey in 2008. A total of five isolates of Pseudophloeosporella sp. were obtained from the infected leaves of yam plants. All of the isolates were identified as Pseudophloeosporella dioscoreae based on their morphological and cultural characteristics. A phylogenetic tree derived from the internal transcribed spacer sequences of the fungal isolates showed that the fungus is distinctly separated from species in other related genera. P. dioscoreae isolates caused very tiny spots on leaves of yam plants two weeks after artificial inoculation which were similar to those observed in the field. This is the first report that Pseudophloeosporella dioscoreae causes leaf spot in yams in Korea.

Notes on Some New Species of Psathyrella

This study contains descriptions and illustrations of three new and noteworthy taxa of the genus Psathyrella from Korea. Among them, Psathyrella pervelatoid, P. koreana, and P. utriformcystis are new to science. All collections cited here are deposited in the Herbarium Conservation Center of National Academy of Agricultural Sciences.

Occurrence of Clubroot on Pak-Choi Caused by Plasmodiophora brassicae

Clubroot symptoms occurred severely on roots of Pak-Choi (Brassica campestris ssp. chinensis) grown in greenhouses in Gwangju city, Gyeonggi province, Korea in September, 2008. The incidence of the disease symptoms reached as high as 90% in three greenhouses investigated. The root galls collected from the greenhouses were sectioned using a scalpel and observed by light microscope. Many resting spores were found in the cells of the root gall tissues. Suspension of resting spores was prepared from the root galls and inoculated to roots of healthy Pak-Choi plants. Each of five resting spore suspensions caused clubroot symptoms on the roots, which were similar to those observed during the greenhouse survey. Resting spores of the pathogen were observed in the cells of the affected roots. The clubroot pathogen was identified as Plasmodiophora brassicae based on its morphological and pathological characteristics. This is the first report that Plasmodiophora brassicae causes clubroot of Pak-Choi.

New Record of the Genus Calyptella from Korea

Calyptella capula is reported for the first time in Korea. It was found in spring in Chungcheongbuk-do, central Korea, growing in a dead stalk of Sesamum indicum. A description and molecular phylogenetic analyses are reported.

Occurrence of Anthracnose on Highbush Blueberry Caused by Colletotrichum Species in Korea

A total of 82 isolates of Colletotrichum species were obtained from anthracnose symptoms of highbush blueberry trees grown in the Gochang area of Korea during a disease survey in 2008. Out of the isolates, 75 were identified as Colletotrichum gloeosporioides and the others as C. acutatum based on their morphological and cultural characteristics. Twenty six of C. gloeosporioides isolates produced their teleomorph Glomerella cingulata in PDA culture. Three isolates of each C. gloeosporioides and C. acutatum caused anthracnose symptoms on the leaves by artificial inoculation, which were similar to what was observed in the orchards. Previously in Korea, only C. gloeosporioides has been reported as causing anthracnose in blueberries. This is the first report that C. acutatum causes anthracnose in the highbush blueberry in Korea.

New Species of Agaricales

Clitocybe alboinfundibulliforme sp. nov. is widely distributed in Korea. Volvariella koreana sp. nov. is rarely distributed in Korea. These taxa were occasionally found together at the same place. Both of these species seem to be associated with each other. These two species are fully described and illustrated in this paper.

Mating Types and Optimum Culture Conditions for Sexual State Formation of Fusarium fujikuroi Isolates

Twenty-five isolates of Fusarium fujikuroi acquired from rice seeds and rice plants evidencing symptoms of Bakanae disease were evaluated to determine their mating types and characterize the formation of their sexual state. The mating types of the isolates were evaluated via multiplex PCR with the diagnostic primers of the mating-type (MAT) region: GFmat1a, GFmat1b, GFmat2c, and GFmat2d. Among the 25 isolates, 11 were identified as MAT-1 (male), and 14 as MAT-2 (female). Four MAT-1 isolates and three MAT-2 isolates were mated and cultured to evaluate the optimal culture conditions for the production of their sexual states. Among four tested media, 10% V8 juice agar proved optimal for the perithecial production of the isolates. The isolates also generated the largest numbers of perithecia when incubated at 23degrees C in alternating cycles of 12 hr fluorescent light and NUV fluorescent light and 12 hr darkness.

Occurrence of Fuligo gyrosa Causing Slime Mold of Oriental Melon

Recently, a severe slime mold infestation affected oriental melon plants in fields in Chilgok county, Gyeongbuk province, Korea. Specimens were collected from the fields and examined for identification. A species of Myxomycetes, Fuligo gyrosa, was identified based on its morphological characteristics. This is the first report that F. gyrosa causes slime mold of oriental melon.

Occurrence of Dumontinia tuberosa in Korea

Thirty-seven single spore isolates were obtained from specimens of ascomycetous fruiting bodies collected from Mt. Suri, Anyang in Korea. The fungal specimens and isolates were identified as Dumontinia tuberosa based on their morphological and cultural characteristics. This is the first record of this fungus occurring in Korea.

Occurrence of Anthracnose on Welsh Onion Caused by Colletotrichum circinans

Anthracnose occurred frequently on leaf sheaths of Welsh onions grown in Gangwha island, Korea in November, 2007. The disease incidence was as high as 30% in five fields investigated. A total of 20 single spore isolates of Colletotrichum species were obtained from the affected plants, and all the isolates were identified as Colletotrichum circinans based on their morphological and cultural characteristics. Three isolates of the fungus caused anthracnose symptoms on the leaf sheaths of Welsh onions by artificial inoculation, which were similar to those observed during the field survey. In this study, the mycological and pathological characteristics of C. circinans identified as causing anthracnose of Welsh onions are clarified.

In Vitro Antagonistic Characteristics of Bacilli Isolates against Trichoderma spp. and Three Species of Mushrooms

Twenty isolates of Bacillus species obtained from livestock manure composts and cotton-waste composts were tested for their antagonistic effects in vitro against three green mold pathogens of mushrooms (Trichoderma harzianum, T. koningii, and T. viridescens). However, there exists a possibility Bacillus species may have antagonistic effects against mushrooms themselves, and thus the same 20 isolates were tested in vitro against three species of mushrooms (Flammulina velutipes, Lentinus edodes, and Pleurotus ostreatus). Of the 20 Bacillus species isolates tested, two inhibited mycelial growth of T. harzianum, seven that of T. koningii, and eight that of T. viridescens. Importantly, the bacterial isolates M27 and RM29 strongly inhibited mycelial growth of all the Trichoderma spp. isolates tested. The isolate M27 was subsequently identified as the most effective in inhibiting mycelial growth of all the Trichoderma species. Interesting results of the effect Bacillus isolates had upon the mushroom species followed. It was found that most Bacillus isolates except 5T33 at least somewhat inhibited mycelial growth of the three mushroom species or some of the mushrooms. Furhermore, the antagonistic effects of the bacterial isolates against the three species of mushrooms varied depending on the mushroom species, suggesting a role for mushroom type in the mechanism of inhibition. The bacterial isolates M27 and RM29 were identified as having the most antagonistic activity, inhibiting mycelial growth of all the Trichoderma spp. as well as mycelial growth of the three species of mushrooms. These results suggest that the bacterial isolates and their antagonistic effects on green mold pathogens should be further studied for their practical use for biological control of green mold in the growing room of the mushrooms.

Occurrence of Anthracnose on Chinese Mallow Caused by Colletotrichum malvarum

Anthracnose symptoms were frequently observed on leaves, petioles, and stems of Chinese mallow grown in Namyangju, Korea, during a disease survey performed in November, 2007. The disease incidence was as high as 30% in the 12 greenhouses investigated. A total of 38 isolates of the Colletotrichum species were obtained from the anthracnose symptoms, and all the isolates were identified as Colletotrichum malvarum based on their morphological and culture characteristics. Three isolates of the fungus caused anthracnose symptoms on leaves and stems following artificial inoculation, which were similar to those observed during the greenhouse survey. In this study, mycological and pathological characteristics of C. malvarum identified as causing anthracnose of Chinese mallow were clarified.

Identification of Microdochium bolleyi Associated with Basal Rot of Creeping Bent Grass in Korea

Symptoms of basal rot occurred sporadically on creeping bent grasses growing at a golf course in Hampyeong, Korea in April 2007. Ten isolates of Microdochium sp. were obtained from leaves and crowns of the diseased bent grasses. All isolates were identified as Microdochium bolleyi based on morphological, cultural, and molecular characteristics. This is the first report on M. bolleyi associated with basal rot on creeping bent grass in Korea.

Occurrence of Anthracnose on Fruits of Asian Pear Tree Caused by Colletotrichum acutatum

Anthracnose symptoms often occurred on fruits of Asian pear trees grown in Anseong, Naju, Seonghwan and Pyeongtaek in Korea during the harvesting period from 2000 to 2005. A total of 28 isolates of Colletotrichum sp. were obtained from the anthracnose symptoms. All the isolates were identified as Colletotrichum acutatum based on their morphological and cultural characteristics. Four isolates of the fungus were tested for pathogenicity to fruits of Asian pear tree by artificial inoculation. All the isolates induced anthracnose symptoms on the fruits by wound inoculation but not by unwound inoculation. The anthracnose symptoms induced by artificial inoculation were similar to those observed in the orchard. This is the first report of anthracnose of Asian pear tree caused by Colletotrichum acutatum.