First Report of Anthracnose Disease on Jatropha curcas Caused by Colletotrichum gloeosporioides in Korea

In the summers of 2010 and 2011, an anthracnose disease was observed on the Jatropha curcas L. grown at the research field of Gyeongsangnam‐do Agricultural Research and Extension Services, South Korea. The symptoms included the appearance of dark brown spots on the leaf and fruit and the mummification of the fruit. The causal fungus formed grey to dark grey colony on potato dextrose agar. Conidia were single celled, ovoid or oblong, and 8–15 × 3–5 μm in size while seta was dark brown, cone‐shaped and 25–46 × 2–6 μm in size. The optimum temperature for growth was approximately 30°C. On the basis of mycological characteristics, pathogenicity test and molecular identification using internal transcribed spacer rDNA sequence, the fungus was identified as Colletotrichum gloeosporioides. To our knowledge, this is the first report of an anthracnose caused by C. gloeosporioides on J. curcas plant in Korea.     

Anthracnose Caused by Colletotrichum horii on Sweet Persimmon in Korea: Dissemination of Conidia and Disease Development

Anthracnose disease caused by Colletotrichum horii (C. gloeosporioides), results in considerable economic damage to sweet persimmon in southern Korea yearly. This study deals with the life cycle of the pathogen in terms of seasonal fluctuations of spore dispersal and the development of disease based on field surveys, spore potential and fungal isolation. Anthracnose disease was observed first on twigs in the last week of May and reached an incidence of 1.2%. Subsequently, the disease increased rapidly and reached an incidence of 86% by the end of July. Infection of fruits started in mid‐June (2.8%) and increased gradually to 64.4% by the end of July. In severely infected orchards, 46.2% of diseased fruits were dropped. The pathogen began releasing conidia in the first week of May and continued until the end of September. The maximum release of spores was observed in mid‐July. To determine the optimal use of chemicals for control of anthracnose, the following spray programme was evaluated. Spraying two or three times resulted in 89.4 and 93% control, respectively, whereas spraying more than four times led to 100% control. In comparison, the disease rate of unsprayed trees was 89.8%. To control anthracnose effectively, it is recommended to take steps to eliminate inoculum sources in sweet persimmon orchards before spraying chemicals.     

Antifungal effects of dimethyl trisulfide against Colletotrichum gloeosporioides infection on mango

Colletotrichum gloeosporioides, one of the main agents of mango anthracnose, causes latent infections in unripe mango and can lead to huge losses during fruit storage and transport. Dimethyl trisulfide (DMTS) is an antifungal agent produced by several microorganisms or plants, but its effects on the infection process of C. gloeosporioides have not been well characterized. A histological investigation demonstrated that DMTS exhibits strong inhibitory effects on the infection process of C. gloeosporioides in planta by inhibiting the germination of conidia and formation of appressoria, damaging cytoplasm to cause cells to vacuolate and contributing to deformation of appressoria prior to penetration. This is the first study to demonstrate antifungal activity of DMTS against C. gloeosporioides on mango by suppression of the infection process, thus providing a novel postharvest biorational control for mango anthracnose.     

First Report of Dragon Fruit (Hylocereus undatus) Anthracnose Caused by Colletotrichum truncatum in China

Anthracnose disease was detected from dragon fruit (Hylocereus undatus) at a market of Yuanjiang County, Yunnan Province, China. The results of pathogenicity test, morphology studies and sequence analyses based on ITS and β‐tubulin loci indicated that the disease was caused by Colletotrichum truncatum. The pathogen produced elliptic, yellow spots with chlorotic halos on the surface of the fruit, and the lesion become depressed gradually. Grey to black acervuli appeared on the lesion surface in concentric circles later. This is the first report of dragon fruit anthracnose caused by this pathogen in China.     

First Report of Frosty Mildew on Salix koreensis Caused by Mycopappus alni in Korea

A frosty mildew was observed on leaves of Salix koreensis in two localities of Korea during 2011 and 2012. The main signs and symptoms were expressed as conical white to cream coloured tufts of the causal fungus on the brown lesions, followed by premature defoliation. Based on morphological observations, cultural characteristics and phylogenetic analyses of rDNA‐ITS, the fungus was identified as Mycopappus alni, which has been known to be associated with frosty mildews on Alnus spp., Betula spp., Crataegus chlorosarca and Pyrus pyrifolia. Pathogenicity test was conducted twice with the same results, fulfilling Koch's postulates. This is the first case of Salix–Mycopappus association as well as the first report of frosty mildew on S. koreensis.     

Immunoassay‐based Techniques for Early and Specific Detection of Latent Postharvest Anthracnose in Mango

The postharvest anthracnose pathogen Colletotrichum gloeosporioides inciting latent or quiescent infection of mango was detected in early stages using immunoassay methods. Twenty‐five pathotypes isolated from different agroclimatic zones of Tamil Nadu, Karnataka and Pondicherry, India, revealed the variation in protein profile analysis (SDS‐PAGE). The polyclonal antibodies (PCA) were raised against the unfractioned mycelial protein (UMP) and a 40‐kDa polypeptide present in all pathotypes. Standardization of antigen and antiserum dilutions revealed that an antigen dilution of 1 : 200 (protein concentration of 20 μg/ml) and antiserum dilution of 1 : 100 (protein concentration of 40 μg/ml raised against UMP) and 1 : 200 (protein concentration of 20 μg/ml raised against 40 kDa polypeptide) was found to be optimum for the detection of anthracnose pathogen. Both antisera detected the C. gloeosporioides antigen in enzyme‐linked immunosorbent assays (ELISAs), dot immunobinding assays (DIBAs) and Western blots. The specificity in reaction was compared by isolating other Colletotrichum spp. from various hosts viz., C. lindemuthianum (beans), C. falcatum (sugarcane), C. musae (banana), C. capsici (chillies) and Botryodiplodia theobromae (mango). The antisera generated against UMP revealed the cross‐reaction with other host isolates and mango stem end rot pathogen (B. theobromae). The PCA raised against 40‐kDa polypeptide exhibited the specific reaction with C. gloeosporioides isolates in all the immunoassay techniques. By utilizing both PCA, the presence of latent infection was observed in healthy‐looking leaves, flowers and fruits in orchard conditions. The fruit tissues recorded high absorbance values followed by flowers and leaves in all the detection methods. The ELISA technique was also useful in assessing the pathogen inoculum at various biocontrol formulations sprayed mango trees under field conditions. The fluorescent pseudomonad strains mixture (KFP1 + FP7) amended with chitin sprayed at 30‐day intervals revealed the significant reduction in pathogen load than other formulations and unsprayed control.     

Characterization and Pathogenicity of Colletotrichum truncatum Causing Stem Anthracnose of Red‐Fleshed Dragon Fruit (Hylocereus polyrhizus) in Malaysia

During August 2010 and January 2011, 10 isolates of Colletotrichum were recovered from stem anthracnose lesions of Hylocereus polyrhizus in the states of Kedah and Penang, Malaysia. Based on the morphological characteristics of colony colour and appearance, and shapes of conidia as well as sequences of internal transcribed spacer regions (ITS), β‐tubulin, actin (ACT) and glyceraldehyde 3‐phosphate dehydrogenase (GAPDH), the fungus was identified as Colletotrichum truncatum. Pathogenicity test showed that C. truncatum isolates were pathogenic to the artificially inoculated H. polyrhizus stem. This is the first report of C. truncatum causing anthracnose on H. polyrhizus stems in Malaysia.     

Significance of Microsclerotia in the Epidemiology of Black Pepper Anthracnose and an Approach for Disease Management in Nurseries

Anthracnose incited by Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. is a wide spread and economically important disease of black pepper. In the present study, role of microsclerotia (MS) in the trans‐seasonal perpetuation of C. gloeosporioides was investigated. Microscopical examination of the runner shoots exhibiting necrotic lesions revealed the presence of dark, melanized structures which resembled MS. The excised necrotic regions when subjected to high humidity produced acervulus with setae. Under in vitro conditions, C. gloeosporioides produced MS predominantly on the aerial surface as inseparable congregations, enmeshed in the mycelial mats in potato dextrose broth and as individual units 7–8 days after incubation on glass slides. Sequential events in the formation of MS included germination of conidia, formation of conidial anastomosis tubes, aggregation of hyphae, and the formation of melanized microsclerotial bodies. Three types of microsclerotial germination were observed under in vitro conditions viz., sporogenic, myceliogenic and both. PCR confirmation with CgInt species‐specific primer and ITS4 resulted in 450‐bp amplification. Since, runner shoots are predominantly used as propagating material in black pepper, an approach was devised to manage anthracnose under nursery conditions by treating the 2‐ to 3‐node cuttings (nursery planting material) with carbendazim (12%)—mancozeb (63%) @ 0.1% for 30 min. The results of the study suggests a new facet in the disease cycle of black pepper anthracnose, indicating that the pathogen survives as microsclerotia in planta and could act as a potential source of inoculum.     

First Report of Leaf Spot Disease in Angelica dahurica Caused by Phoma bellidis in China

Angelica dahurica is a perennial herb belonging to the Umbelliferae family that has been used as a valuable traditional Chinese medicine. In August 2013, leaf spot disease in A. dahurica was first observed at the Medicinal Herb Garden in Shenyang Agricultural University, Shenyang, Liaoning, China. Morphological assessment, evaluation of culture characteristics, internal transcribed spacer and beta‐tubulin sequence analysis and pathogenicity identified the causal agent as Phoma bellidis. To our knowledge, this is the first report of leaf spot disease in A. dahurica that was caused by P. bellidis.     

武汉梅花炭疽病病菌的多样性研究

炭疽病是梅花（Prunus mume）栽培中的重要病害,对梅花的栽培构成严重威胁。本研究从武汉发病的梅花叶片样品上分离、获得了170个炭疽病菌菌株,它们在形态特征、致病性、分子遗传水平等方面都表现出较大的差异。按菌落形态、色素分泌、拟菌核产生、分生孢子及孢子梗形态和大小等形态特征将梅树炭疽病菌分为7种类型,其中Ⅵ型和Ⅶ型菌株在PDA培养基上可以连续产生大量的有性后代。7种类型的菌株只能侵染梅花、樱树、梨树、苹果、桃树、杏树等蔷薇科园艺植物,并且存在着明显的致病力分化,但不侵染吉祥草、柑桔、大叶黄杨、豇豆、紫荆、高粱等供试的其它科植物。依据致病力可将梅树炭疽病菌分为强、中、弱3类。ITS序列表明它们均属于胶孢炭疽（Colletotrichum gloeosporioides）。对其中7种类型36个梅树炭疽病菌菌株的进行了RAPD聚类分析,在55%相似水平上,供试菌株可以分为3组,所聚类群与形态学类型和致病力分化所形成的强、中、弱3类没有明显的相关性。表明梅花炭疽病菌菌株间存在丰富的遗传多样性。     

First Report of Cercospora Leaf Spot of Burcucumber Caused by Cercospora citrullina in Korea

Burcucumbers (Sicyos angulatus) showing necrotic leaf spots were found in several locations in Korea during 2008–2012. The causal agent was a fungus that was identified as Cercospora citrullina, based on morphological characteristics as well as sequences of the ribosomal DNA internal transcribed spacer region. Although C. citrullina has been known to attack various cucurbitaceous plants, this is the first report of this fungus on S. angulatus.     

First Report of Dieback of Mango Caused by Fusarium decemcellulare in China

During 2009–2011, a dieback disease of mango (Mangifera indica) has recently emerged on mango trees in Panzhihua City, Sichuan province of China. The disease is characterized by large irregular brown‐coloured speckles on the petioles and twigs, vascular necrosis and dry leaves and complete twig mortality. Fusarium species were isolated repeatedly from the infected petioles and twigs. The species was identified as Fusarium decemcellulare Brick based on morphology and sequence analysis of Translation Elongation Factor‐1alpha (TEF‐1α) gene. Koch's postulates were fulfilled by pathogenicity tests on potted mango seedlings. To our knowledge, this is the first record of dieback on mango caused by F. decemcellulare in China.     

Differential Organ Distribution,Pathogenicity and Benomyl Sensitivity of Colletotrichum spp. from Blackberry Plants in Northern Colombia

Blackberry anthracnose, caused by Colletotrichum spp., is an important disease of cultivated blackberry in the world. In Colombia, it is the number one limiting factor for commercial production. This study was conducted to determine the species of Colletotrichum infecting blackberry plants as well as the organ distribution, pathogenicity and response to benomyl of the isolated strains. Sixty isolates from stems (n = 20), thorns (n = 20) and inflorescences (n = 20) were identified as Colletotrichum acutatum and Colletotrichum gloeosporioides by a species‐specific polymerase chain reaction (PCR). Both Colletotrichum species were found in the same plant but on different organs. Colletotrichum gloeosporioides species predominated in thorn lesions (n = 16) and C. acutatum in stems (n = 15) and inflorescence (n = 15). Pathogenicity assays on detached blackberry organs demonstrated differences between the two species with an average period of lesion development of 8.7 days for C. gloeosporioides and 10.3 days for C. acutatum. Wound inoculated organs had 90% disease development compared to 17.5% in non‐wounded. All C. acutatum isolates (n = 34) were benomyl tolerant, whereas C. gloeosporioides isolates (n = 26) were 30.7% sensitive and 69.2% moderately tolerant. Phylogenetic analysis with ITS sequences of a subset of 18 strains showed that strains classified as C. gloeosporioides had 100% identity to Colletotrichum kahawae, which belongs to the C. gloeosporioides species complex, whereas C. acutatum strains clustered into two different groups, with high similarity to the A2 and the A4 molecular groups. These data demonstrate for the first time the differential distribution of both species complexes in blackberry plant organs and further clarifies the taxonomy of the strains.     

Genetic Diversity and Pathogenic Variability of Colletotrichum truncatum Causing Anthracnose of Pepper in Malaysia

Colletotrichum truncatum was initially described from pepper and has been reported to infect 180 host genera in 55 plant families worldwide. Samples were collected from pepper plants showing typical anthracnose symptoms. Diseased samples after isolation were identified as C. truncatum based on morphological characters and ITS‐rDNA and β‐tubulin sequence data. Intersimple sequence repeat (ISSR) markers were used to estimate genetic diversity in C. truncatum from Malaysia. A set of 3 ISSR primers revealed a total 26 allele from the amplified products. Cluster analysis with UPGMA method clustered C. truncatum isolates into two main groups, which differed with a distance of 0.64. However, the genetic diversity of C. truncatum isolates showed correlation between genetic and geographical distribution, but it failed to reveal a relationship between clustering and pathogenic variability. Phylogenetic analyses discriminated the C. truncatum isolates from other reference Colletotrichum species derived from GenBank. Among the morphological characters, shape, colour of colony and growth rate in culture were partially correlated with the ISSR and phylogenetic grouping. Pathogenicity tests revealed that C. truncatum isolates were causal agents for pepper anthracnose. In the cross‐inoculation assays, C. truncatum isolates were able to produce anthracnose symptoms on tomato, eggplant, onion, lettuce and cabbage. A pathogenicity and cross‐inoculation studies indicated the potential of C. truncatum for virulence and dominancy on plant resistance.     

First Report of Choanephora Rot of Okra Caused by Choanephora cucurbitarum in Korea

In July and August 2013, blossom blight and soft rot of pods were observed on okra in experimental fields in Iksan and Jeju, Korea. Infection started in fading flower petals, spread to entire flowers and young pods, resulting in blighted blossoms and soft rot of pods. Severe infection caused early falling of blossoms and fruit drop, reducing plant vigour in the summer season. On the basis of the morphological characteristics and phylogenetic analyses of two molecular markers ITS rDNA and D1/D2 region of the LSU, the fungus was identified as Choanephora cucurbitarum. A pathogenicity test was carried out to fulfil Koch's postulates. To our knowledge, this is the first report of C. cucurbitarum on okra in Korea.     

First report of anthracnose caused by Colletotrichum gloeosporioides on Boehravia diffusa in India

Leaf spot symptoms were observed on the leaves of Boehravia diffusa L. plants from different regions of Bilaspur, Himachal Pradesh, India. The symptoms initially appeared as a small light-pale coloured, circular spots enlarge gradually and ultimately leading to drying of the leaves. The disease was found to be caused by a fungus. The fungus was cultured on potato dextrose agar medium and identified as Colletotrichum gloeosporioides. According to the literature, this is thefirst report of anthracnose disease of B. diffusa caused by C. gloeosporioides in India.     

New report of Colletotrichum gloeosporioides causing anthracnose of Pisonia alba in India

Anthracnose was observed on Pisonia alba plants as irregular, black, necrotic spots that often coalesce to form large necrotic area on leaves. A fungus, consistentlyisolated from symptomatic leaves was identified as C. gloeosporioides on the basis of morphological and cultural characteristics. The fungus produced white mycelia, which became dark grey with later formation of numerous salmon pink coloured spore masses. The conidia were hyaline, unicellular, aseptate and oval to cylindrical with rounded ends and were 10–20 μm long and 3–5 μm wide. Pathogenicity tests conducted on healthy detached leaves of Pisonia plants showed typical anthracnose symptoms afterfour to seven days. This is the first report of anthracnose of Pisonia alba.     

Quantification of Yield Losses Due to Anthracnose Stalk Rot on Corn in Brazilian Conditions

The anthracnose stalk rot of corn (ASR), caused by Colletotrichum graminicola, is a major disease of this crop and occurs in most Brazilian regions where corn is grown. Despite its widespread occurrence, there are no estimates of the effect of ASR on the yield of corn under the Brazilian conditions. In this study, we evaluated the effect of ASR on corn hybrids yield. Two experiments were conducted (first crop 2007/2008 and second crop, 2009) in areas with a history of occurrence of leaf anthracnose and ASR. Five hybrids were evaluated in the first and second crops: AG1051, BRS 1001, BRS 1010, BRS 1035, P30F80 and BRS 1010, 2B710, P30F80, DKB390, BRS 1035, respectively. At harvest, we evaluated the incidence of plants with anthracnose stalk rot (IPASR), and we selected pairs of healthy and diseased plants to quantify the effect of ASR in the ear weight (EW), grain weight (GW) and the weight of a sample containing 100 kernels (W100). The IPASR was higher in the hybrid BRS 1010 (21.87 and 45.28%, first and second crops, respectively). The EW, GW and W100 were lower in diseased plants in all hybrids. The mean weight loss in the first season was EW 29.03%, GW 27.83% and W100 17.08%, and the second season was EW 27.75%, GW 25.60% and W100 16.99%. The most affected hybrids with weight loss in the first crop were AG1051 (EW 34.31%, GW 33.05%, W100 19.96%) and BRS 1035 (EW 34.74%, GW 34.65%, W100 22.31%). In the second crop, were P30F80 (EW 30.72%, GW 30.92%, W100 19.24%), DKB390 (EW 30.61%, GW 29.81%) and 2B710 (W100 19.27%). Corn yield was strongly affected by ASR.     

Characterization of Colletotrichum orchidophilum,the agent of black spot disease of vanilla

Black spot symptoms were reported on vanilla plants in Reunion Island in 2011. They have repeatedly reduced annual pod production by 10% to 30%. The disease is characterized by dark spots that appear in slight depressions on flowers, pods, leaves and stems. The spots then develop into broad clearly depressed necrotic plaques. Morphological and molecular analyses, as well as pathogenicity tests, identified the fungus Colletotrichum orchidophilum (Ascomycota) as the causal agent of the disease. Inoculation tests in controlled conditions confirmed that the two C. orchidophilum strains isolated from fruit lesions are pathogenic on the leaves and fruits of Vanilla planifolia (accessions CR0001 and CR0020). However, these strains induced symptoms only when the epidermis of leaves and fruits had been punctured by a needle. In the absence of injury, no symptom appeared. Colletotrichum arxii and Fusarium proliferatum (Ascomycota) are fungal species that are also frequently isolated from black spot lesions. However, they are not pathogenic to vanilla. This is the first report of C. orchidophilum in Reunion Island. It is also the first demonstration of C. orchidophilum's pathogenicity to an orchid. Simple preventive control measures were proposed to reduce the incidence of black spot disease in vanilla plots.