Report Of Anthracnose Research Articles

First report of anthracnose on Schima mertensiana caused by Colletotrichum sp. in Japan

In November 2015, leaf blight on Schima mertensiana was found in Chichijima, Bonin Islands, Tokyo, Japan. The causal fungus was isolated from the leaf symptoms and identified as Colletotrichum sp. based on morphological examination and molecular analysis using ITS, ACT, CHS-1, CAL, and TUB2 sequences. Leaf blight similar to the natural symptoms developed after leaves were inoculated with the isolate. This is the first report of leaf blight on S. mertensiana caused by Colletotrichum species in Japan, and anthracnose, “tanso-byo” in Japanese, is proposed as the disease name.

Anthracnose pathogen of the succulent plant Echeveria ‘Perle von Nürnberg’

Zhangzhou in Fujian province is the primary habitat for the succulent plant Echeveria ‘Perle von Nurnberg’ (Crassulaceae), which has seriously suffered from anthracnose disease in recent years. Plants with typical disease symptoms were collected from three planting bases in Zhangzhou, and pathogens were isolated for further identification. The pathogen was identified as Colletotrichum destructivum by morphological observation, rDNA-ITS, Actin, and TUB2 gene sequence analysis, and pathogenicity identification. This is the first ever report of anthracnose caused by C. destructivum on Echeveria ‘Perle von Nurnberg.’

First Report of Anthracnose Caused by Colletotrichum americae-borealis on Greenhouse-Grown Licorice in China

First Report of Anthracnose Caused by <i>Colletotrichum americae-borealis</i> on Greenhouse-Grown Licorice in China

First Report of Anthracnose of Peach (Prunus persica) Caused by Colletotrichum fructicola in Korea

First Report of Anthracnose of Peach (<i>Prunus persica</i>) Caused by <i>Colletotrichum fructicola</i> in Korea

First Report of Anthracnose of Clausena lansium Caused by Colletotrichum scovillei in China

First Report of Anthracnose of <i>Clausena lansium</i> Caused by <i>Colletotrichum scovillei</i> in China

First Report of Anthracnose on Machilus ichangensis Caused by Colletotrichum siamense in China

First Report of Anthracnose on <i>Machilus ichangensis</i> Caused by <i>Colletotrichum siamense</i> in China

First Report of Colletotrichum siamense Causing Anthracnose on Jasminum mesnyi in China

First Report of <i>Colletotrichum siamense</i> Causing Anthracnose on <i>Jasminum mesnyi</i> in China

First Report of Anthracnose Caused by Colletotrichum spinaciae on Vicia sativa in China

First Report of Anthracnose Caused by <i>Colletotrichum spinaciae</i> on <i>Vicia sativa</i> in China

First Report of Anthracnose Causing Both Crown and Fruit Rot of Strawberry by Colletotrichum siamense in North Carolina

First Report of Anthracnose Causing Both Crown and Fruit Rot of Strawberry by <i>Colletotrichum siamense</i> in North Carolina

First Report of Anthracnose on Pecan (Carya illinoensis) Caused by Colletotrichum nymphaeae in China

From 2015 to 2017, anthracnose symptoms on pecan were found in Zhejiang province. Field investigations conducted from July to November in 2017 found anthracnose symptoms on at least 50% leaves in a Jiande pecan orchard (N 29°25′17.7″, E 119°18′10.7″). More leaves located at the bottom were infected than in higher parts, and the top leaves hardly showed infection. At first, light yellow spots appeared and then enlarged and, finally, developed into characteristic anthracnose symptoms including irregular-shaped lesion with a chlorotic halo. From September to November, anthracnose symptoms were also observed on the fruits. Infected fruits became dark, rotten, mummified, and finally dropped with a rate of 30 to 50%. Spores were isolated from the fresh infected tissues following the methods of Velho et al. (2014) and were examined under a microscope. Vegetative mycelium was hyaline, smooth-walled, septate, and branched. Conidia were smooth-walled, aseptate, hyaline, guttulate, straight, fusiform to cylindric with one end round and one end round to acute, with a size of 10.1 to 15.8 µm long (mean = 12.3 µm, n = 60) and 3.4 to 4.9 µm wide (mean = 4.1 µm, n = 60). Appressoria were single, medium brown, smooth-walled, elliptical, clavate or irregular in outline, entire, undulate to lobate margin, with a size of 5.4 to 10.5 µm long (mean = 8.1 µm, n = 30) and 4.0 to 6.5 µm wide (mean = 5.2 µm, n = 30). Genomic DNA of 15 isolates was extracted, and six gene sequences (ITS, GAPDH, CHS-1, CAL, ACT, and TUB2) were amplified and sequenced as described in Fu et al. (2019) and were submitted to GenBank with accession numbers of MH231421 (ITS), MH793690 (GAPDH), MH793689 (CHS-1), MH793688 (CAL), MH891493 (ACT), and MH796660 (TUB2). BLAST analysis showed that all sequences shared high identity with Colletotrichum nymphaeae (100% with ITS, ACT, and TUB2, and 99% with the other three genes). Phylogenetic analysis showed that the isolates and C. nymphaeae were clustered in the same clade. Based on the results of morphological and molecular analyses, the isolates were identified as C. nymphaeae. Pathogenicity tests were carried out three times on living trees. Healthy leaves and fruits were surface cleaned with sterile soaked cotton, air-dried, and then wounded with a sterilized needle. An aliquot of 10 μl of spore suspension (1.0 × 10⁶ conidia/ml) of C. nymphaeae was dropped on each wound. Each treated leaf or fruit was enveloped by a plastic zipper bag with a sterile soaked cotton in it to keep moisture. Sterile distilled water drops served as controls. After 24 h, cotton pieces and plastic bags were removed. Lesions began to appear on the 7th day after inoculation. The symptoms of inoculated treatment developed and exhibited similarly to those observed in pecan orchards, and no symptom was observed on the control. C. nymphaeae was reisolated from the symptomatic pecan tissues and was reidentified with both morphological and molecular methods. According to Koch’s postulates, C. nymphaeae was confirmed as the cause of the disease. To our knowledge, this is the first report of anthracnose on pecan caused by C. nymphaeae in China.

First Report of Anthracnose of Camellia sasanqua Caused by Colletotrichum aenigma in China

First Report of Anthracnose of <i>Camellia sasanqua</i> Caused by <i>Colletotrichum aenigma</i> in China

First Report of Anthracnose of Mangifera indica Caused by Colletotrichum scovillei in China

First Report of Anthracnose of <i>Mangifera indica</i> Caused by <i>Colletotrichum scovillei</i> in China

First Report of Anthracnose Caused by Colletotrichum gossypii on Tomato in Hainan, China

First Report of Anthracnose Caused by <i>Colletotrichum gossypii</i> on Tomato in Hainan, China

First Report of Anthracnose Caused by Colletotrichum gloeosporioides on Mikania micrantha in Guangdong, China

Colletotrichum gloeosporioides is one of the most important pathogens in the world, capable of infecting at least 1,000 kinds of plants (Phoulivong et al. 2010). Mikania micrantha Kunth (Asteraceae), commonly known as mile-a-minute weed, is an extremely fast-growing, perennial creeping weed. Its native distribution is in Central and South America. It has been present in south China since the 1980s and has caused adverse impact on agricultural production in the established area (Li et al. 2013). In 2014, the incidence of anthracnose disease on M. micrantha reached 65 to 90% in Huizhou city, Guangdong, China, and plant mortality up to 45% was observed (Chen et al. 2006). The disease symptoms appeared as brown spots on the leaves and stems of M. micrantha; as the disease progressed, lesions turned dark brown. The location of the disease gradually expanded and even spread throughout the plant (Chen et al. 2006). Thirty symptomatic leaves were sampled from three regions: north of the city (Boluo, 114°28′ E, 23°18′ N), city center (Huidong, 114°72′ E, 22°98′ N), and south of the city (Huiyang, 114°43′ E, 22°80′ N) in Huizhou. Ten pieces from each leaf were surface sterilized with 70% ethanol for 30 s, and then they were rinsed in sterile distilled water and placed on potato dextrose agar (PDA) medium at 27°C in a dark chamber. Colonies grown on medium were round and carpetlike. Aerial hyphae grew more dense, and colonies became gray and black to dark green color. Conidia group showed visible pink and occasionally visible black dots scattered on the surface of the medium. Microscopic spores observed were cylindrical and colorless, 6 to 18 μm in length, and 3 to 5 μm wide. The identification of one representative isolate (H1) was determined by sequencing of the rDNA internal transcribed spacer regions 1 and 2 and the 5.8S using primers (White et al. 1990), and the sequence of each isolate was deposited in GenBank (accession no. KM501061). A BLAST search showed 100% identity with a C. gloeosporioides strain (accession no. KM357285.1). Isolate H1 was also confirmed as C. gloeosporioides with specific primers Colg 1 (5′-AACCCTTTGTGAACATACC-3′) and Colg 2 (5′-CCCTCCGGATCCCAG-3′) (Chen et al. 2006). The pathogenicity test of isolate H1 was carried out in a greenhouse. Ten plants were grown for 20 days in plastic pots (diameter 20 cm) in sandy soil (pH = 5.48) before inoculation. Isolate H1 was grown on PDA medium for 72 h, and the spores were harvested with sterile distilled water. Aqueous spore suspensions of isolate H1 were adjusted with deionized water to 1 × 10⁸ spores/ml and sprayed on the leaves of the plants. All the plants were then placed in the greenhouse at 25 ± 1°C and assessed for disease symptoms. The inoculated isolate caused symptoms identical to those observed in the field, and it was reisolated from the infected leaves and identified as previously described, and none of the untreated plants showed any signs of infection. To our knowledge, this is the first report of anthracnose caused by C. gloeosporioides on M. micrantha in China.

First Report of Anthracnose Caused by Colletotrichum capsici on Passion Fruit in Taiwan

First Report of Anthracnose Caused by <i>Colletotrichum capsici</i> on Passion Fruit in Taiwan

First Report of Anthracnose Caused by Colletotrichum fioriniae on Eggplant Fruits in Korea

First Report of Anthracnose Caused by <i>Colletotrichum fioriniae</i> on Eggplant Fruits in Korea

First Report of Anthracnose Caused by Colletotrichum tropicale on Sauropus androgynus in China

First Report of Anthracnose Caused by <i>Colletotrichum tropicale</i> on <i>Sauropus androgynus</i> in China

First Report of Anthracnose Caused by Colletotrichum truncatum on Basella alba in China

First Report of Anthracnose Caused by <i>Colletotrichum truncatum</i> on <i>Basella alba</i> in China

First Report of Anthracnose Caused by Colletotrichum brevisporum on Gac (Momordica cochinchinensis) in Thailand.

Gac (Momordica cochinchinensis Spreng) is known as “fruit from heaven” and could promote longevity, health, and vitality (Ishida et al. 2004). Gac fruit has been used as both food and medicine in Thailand. In October 2016, anthracnose-like symptoms were found only on leaves of gac plants in Chiang Mai, Thailand (18.79°N, 98.99°E). Approximately half of the plants in a 0.3-ha field of gac were symptomatic. Spots on leaves appeared as circular to irregular in shape, medium brown to blackish in color, and 0.5 to 1.5 cm in diameter. On necrotic lesions, small and black fruiting bodies developed in concentric rings. Abundant brown setae and hyaline, cylindrical, guttulate conidia were observed from necrotic leaves by microscope. To isolate the causal organism, fragments from the lesion margins were surface disinfested with 75% ethanol for 40 s and rinsed thoroughly with sterile distilled water. The fragments were then placed on potato dextrose agar (PDA) and incubated at 26°C in the dark. Six isolates with similar morphology were isolated from single spores. Colonies on PDA at 25°C for 7 days were cottony, grayish white to gray, dark brown at the center in reverse, with orange conidial mass. Conidia (n = 100) were hyaline, one-celled, smooth walled, cylindrical with round ends, guttulate, and 10.5 to 16.8 × 4 to 6 μm. Appressoria (n = 50) formed in culture were brown to dark brown, ovoid or slightly irregular, and 9 to 12 × 7 to 10 μm. The internal transcribed spacer (ITS), actin (ACT), and calmodulin (CAL) gene regions from all six isolates were amplified with primer pairs ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′)/ITS4 (5′-TCCTCCGCTTATTGATATGC-3′), ACT-512F (5′-ATGTGCAAGGCCGGTTTCGC-3′)/ACT-783R (5′-TACGAGTCCTTCTGGCCCAT-3′), and CAL-228F (5′-GAGTTCAAGGAGGCCTTCTCCC-3′)/CAL-2Rd (5′-TGRTCNGCCTCDCGGATCATCTC-3′), respectively (Cai et al. 2009). The resulting 558-bp ITS, 259-bp ACT, and 661-bp CAL sequences from all six isolates were 100% identical. Sequences of isolate MBG16102401 were deposited in GenBank (accession nos. MH063256 for ITS, MH063257 for ACT, and MH063258 for CAL), and BLAST searches showed 100% identity with those of Colletotrichum brevisporum sequences (accession nos. KY986893.1 for ITS, KU315567.1 for ACT, and KU319454.1 for CAL), respectively. The isolate MBG16102401 was deposited at the culture collection of the Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, for future reference. Based on morphological and molecular characteristics, the pathogen was identified as C. brevisporum (Noireung et al. 2012). In pathogenicity test, leaves of 15 potted gac plants (4 weeks old) were pinpricked with a sterile needle and inoculated by spraying onto the leaves with a conidial suspension (10⁶ conidia/ml). For the control, wounded leaves of 15 gac plants were sprayed with sterilized distilled water. Approximately, each gac plant has 8 to 10 leaves. These inoculated plants were kept in a greenhouse (temperature 25°C; relative humidity 90%). The inoculation experiments were replicated three times, and each replicate included five gac plants. Ten days later, inoculated plants developed typical anthracnose symptoms identical to those observed in the field, whereas the control plants remained healthy. C. brevisporum was successfully reisolated from symptomatic leaves to fulfill Koch’s postulates. To our knowledge, this is the first report of C. brevisporum as a pathogen on M. cochinchinensis in Thailand as well as in the world (Farr and Rossman 2018). The identification of the pathogen is important for providing management recommendations to growers, which have a significant economic impact on gac fruit production in Thailand.

First Report of Colletotrichum siamense Causing Anthracnose on Partridge tea (Mallotus oblongifolius) in China

Partridge tea (Mallotus oblongifolius [Miq.] Mull.Arg.) is an important medicinal plant in Hainan province of China used in tea making. During April 2017, circular necrotic lesions were observed on partridge tea plants with a disease incidence of 25% in an experimental station of Hainan University (110.19° E, 20.03° N) in Haikou, Hainan province, China. The lesions began as small circular spots, which later developed into larger spots (diameter of 1.2 to 2.9 mm) with a grayish white center and a dark brown banding pattern on the edges. To identify the pathogen, 10 symptomatic leaves from five plants were collected. Diseased tissue (2 × 2 mm) was cut from the margins of lesions, surface disinfected with 70% ethanol for 5 s, and rinsed four to five times with sterile distilled water. The excised sections were transferred to potato dextrose agar (PDA) plates and incubated at 28°C for 3 to 4 days in the dark. A total of six isolates of Colletotrichum sp. were obtained from diseased tissue, and three strains were randomly selected (Z1, Z4, and Z6) for further analysis. The colonies appeared white to gray on the upper surface of PDA medium at 28°C. Conidia were cylindrical to subcylindrical, rarely clavate, hyaline, and guttulate with 3.96 to 4.21 µm (width) and 12.30 to 18.90 µm (length). These morphological characteristics were compatible with those of species from the Colletotrichum gloeosporioides complex (Weir et al. 2012). For accurate identification, fungal DNA of the three isolates was extracted. Fragments of internal transcribed spacer (ITS) and genomic regions including chitin synthase (CHS-1), actin (ACT), glutamine synthetase (GS), the Apn2–Mat1–2 intergenic spacer, and the mating type (Mat1–2) gene (ApMAT) were amplified and sequenced. These nucleotide sequences were deposited in GenBank (A70814043, ITS; A7110043, CHS-1; A7110049, ACT; A7110052, GS; and A7110046, ApMAT). A BLAST search of the amplified sequences of ITS resulted in 99% similarity with those of C. siamense strain CCL8. ACT sequences resulted in 100% similarity with those of C. siamense strain ICK. CHS-1 sequences showed 99% similarity with those of C. siamense strain WC-OILPALM4. GS gene sequences showed 99% similarity with those of C. siamense strain LQ22, and the ApMAT sequences showed 100% similarity with those of C. siamense strain PAS. Phylogenetic analysis based on the ITS, ACT, CHS-1, GS, and ApMAT amplified sequences was undertaken using MEGA6 software. This analysis clustered the three isolates with the C. siamense strain CBS130417 with high bootstrap support (99%). Therefore, based on their morphological characteristics and sequence similarity data, these isolates were identified as C. siamense. Pathogenicity was confirmed by spraying 10 45-day-old partridge tea plants with a 1 × 10⁶ CFU/ml monosporic suspension. Three strains (Z1, Z4, and Z6) were used to pathogenicity test in a growth greenhouse. Three control plants were treated with sterile water only. After 6 days at 25°C and 85% relative humidity, sunken necrotic spots similar to those observed in the field developed on the inoculated plants. The control plants remained symptomless. C. siamense was successfully reisolated from lesions. C. siamense has been reported on many crops in China (Cheng et al. 2013; Liu et al. 2017; Niu et al. 2016). To our knowledge, this is the first report of anthracnose caused by C. siamense on partridge tea in China.