Gloeosporioides Isolates Research Articles

Colletotrichum gloeosporioides, a new causal agent of citrus post-bloom fruit drop

Citrus post-bloom fruit drop (caused by Colletotrichum acutatum) frequently occurs in the southwestern region of Sao Paulo State, Brazil. A survey of Colletotrichum isolates associated with symptoms of post-bloom fruit drop in Sao Paulo State showed C. gloeosporioides in addition to C. acutatum. The objectives of this study were to confirm the identification of C. gloeosporioides isolated from symptomatic citrus flowers, to test the pathogenicity of C. gloeosporioides isolates, to compare the development of disease caused by C. gloeosporioides and C. acutatum, and to determine the frequency of C. gloeosporioides in a sample of isolates obtained from symptomatic flowers in different regions of Sao Paulo State. Through the use of species-specific primers by PCR, 17.3% of 139 isolates were C. gloeosporioides, and the remaining 82.7% were C. acutatum. The pathogenicity tests, carried out in 3-year old potted plants of sweet oranges indicated that both species caused typical symptoms of the disease including blossom blight and persistent calyces. Incubation periods (3.5 and 3.9 days, respectively, for C. acutatum and C. gloeosporioides) and fruit sets (6.7 and 8.5%, respectively for C. acutatum and C. gloeosporioides) were similar for both species. The incidences of blossom blight and persistent calyces were higher on plants inoculated with C. acutatum than in those inoculated with C. gloeosporioides. Conidial germination was similar for both species under different temperatures and wetness periods. Under optimal conditions, appressorium formation and melanisation were higher for C. gloeosporioides than for C. acutatum. These results indicated that Colletotrichum gloeosporioides is a new causal agent of post-bloom fruit drop.

Cross-infection Potential of <i>Colletotrichum gloeosporioides</i> Penz. Isolates Causing Anthracnose in Subtropical Fruit Crops

Anthracnose, caused by Colletotrichum gloeosporioides Penz. is considered the most important disease in fruit crops in the humid tropics that contributes significantly to preharvest and postharvest losses in mango, papaya, guava, custard apple, pomegranate and other subtropical fruit crops. The objective of this study was to test the ability of the pathogen C. gloeosporioides isolates from seven alternate fruit crops viz., mango, acid lime, custard apple, pomegranate, papaya, cashew and guava to cause disease by cross infection between fruit crops. Information on less infection would facilitate the design of an integrated approach for controlling the preharvest and postharvest losses due to anthracnose under mixed cropping systems especially in mango. Cross inoculation experiments demonstrated variation in the level of host preference and Percent Disease Index (PDI) among C. gloeosporioides isolates .The results revealed that among different fruit crops mango, cashew, pomegranate and custard apple were highly susceptible to the anthracnose disease. Isolate of C. gloeosporioides obtained from mango developed anthracnose symptoms on seedlings on all alternative fruit crops tested except on papaya, but it developed the symptoms on fruits of papaya. Mango isolate recorded maximum PDI of 86.7 on fruits of custard apple and minimum on acidlime fruits (12.8 PDI). The C. gloeosporioides isolates obtained from acid lime, custard apple, pomegranate, cashew and guava could infect the mango leaves and fruits except the papaya isolate which failed to infect the leaves, but produced infection on fruits of mango. Maximum PDI of 19.8 was recorded on mango leaves when inoculated with isolate from cashew, and a minimum PDI of zero and 3.4 was recorded when the leaves were inoculated with papaya and acid lime isolates respectively. Among different isolates of C. gloeosporioides , the cashew isolate was more virulent on mango leaves and fruits, followed by the custard apple and guava isolates. Key words: Colletotrichum gloeosporioides ; Cross inoculation; Fruit crops. DOI: 10.4038/tar.v22i2.2827 Tropical Agricultural Research Vol. 22 (2): 183-193 (2011)

Improved method to induce sporulation of Colletotrichum gloeosporioides, causal fungus of grape ripe rot

Colletotrichumgloeosporioides and C. acutatum are causal agents of grape ripe rot, but with available methods, sporulation of C.gloeosporioides on plate media has been unstable and inferior to that of C. acutatum. To facilitate studies on C. gloeosporioides, I developed an improved method to induce conidiation of this fungus. Isolates of C. gloeosporioides were pre-cultured in potato dextrose broth for 1 week, then pulverized in whole broth. The homogenate was then spread on diluted oatmeal agar (15–20% commercial oatmeal agar medium, 1.5% agar) plates. After the plates were cultured at 25°C under continuous light for another week, the C. gloeosporioides isolates sporulated stably on the plate medium.

First Report of Papaya Fruit Rot Caused by Colletotrichum magna in Brazil

Species of the genus Colletotrichum are commonly reported as pathogens of fruits in tropical regions. Papaya fruits (Carica papaya L.), cv. Golden, with typical lesions of anthracnose, chocolate spot, and/or stem-end rot were collected from 18 papaya-producing areas of northeast Brazil in 2007. One hundred and fifty-five isolates of Colletotrichum spp. were obtained from the fruit lesions and cultured on potato dextrose agar. Pathogenicity tests were conducted by placing a 20-μl drop of 105 conidia ml-1 suspension on a wounded area of two healthy fruits of cv Golden at the climacteric stage. Inoculated fruits were placed in a moist chamber at 26°C (±2) for 48 h. After this period, the plastic covers of the trays used to form the moist chamber were removed and the trays were kept at 26°C (±2) for 98 h when symptoms were assessed. The causal agents of fruit rot were recovered from inoculated fruits showing symptoms of anthracnose and chocolate spot. Conidia from fresh lesions were collected and measured. Conidia dimensions were 13.49 × 3.80 μm, length/width ratio = 3.55 μm. Conidia were predominantly cylindrical to bluntly rounded ends and slightly flattened. All isolates were morphologically similar to Colletotrichum gloeosporioides Penz (1). Molecular analyses of the isolates were carried out with taxon-specific primers for C. acutatum J.H Simmonds and C. gloeosporioides (3). Only one amplicon was detected for eight isolates with the C. gloeosporioides primer. All isolates were genotyped using inter-simple sequence repeat (ISSR) primers. Three groups of isolates were found, one containing the eight C. gloeosporioides isolates, a second group comprised of 141 isolates, and a third contained six isolates. The second and third groups were more similar to each other than to the first C. gloeosporioides group. Thirty two representative isolates of the three ISSR groups were sequenced for the internal transcribed spacer (ITS) and glutamine synthetase (GS) (GenBank Nos. HM163181 and HM015847) regions. With molecular phylogenetic analyses, two well-supported clades were formed, one with the C. gloeosporioides isolates and the other with sequences highly similar (99% similarity) to the two ITS sequences available in GenBank (DQ003310 and GU358453) and the GS region of G. magna Jenkins & Winstead (DQ792873). The latter was reported in the United States and Taiwan (2,4). Isolates of C. magna and C. gloeosporioides are morphologically similar and identification needs to be based on molecular analyses. To our knowledge, this is the first report of C. magna causing rot of papaya fruit in Brazil.

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Studies were performed to analyze the genetic characterization using RFLP-ITS and Intron (primer EI1) markers and the amplification of the cap20 pathogenicity gene by PCR in Colletotrichum gloeosporioides isolates of different hosts plant. The genetic variability was accessed using RFLP-ITS and Intron markers and grouping by UPGMA method. Primers to cap20 gene were constructed using selected sequences of the GenBank (National Center of Biotechnology Information, http://www.ncbi.nlm.nih.gov) with the Primer 3 program. The dendrograms analysis showed that the RFLP-ITS marker was more informative to separate the Colletotrichum sp, and that primer EI1 demonstrated greater genetic diversity. The amplification of the DNA of the Colletotrichum isolates to the cap20 gene with primers P1 and P2 indicated that this gene could present variations into C. gloeosporioides related with the host, and also that it was present in other Colletotrichum sp.

Phenotypic and genetic characterization of Colletotrichum isolates from Belgian strawberry fields

Colletotrichum isolates (457) were collected from strawberry plant tissues with and without typical anthracnose symptoms and from symptomless weeds in 19 Belgian strawberry fields. The isolates were characterized based on genetic, morphological and pathological features. Isolates were classified according to rDNA‐ITS sequencing: 97% of 211 representative isolates were C. acutatum, 2%C. gloeosporioides and 1%C. coccodes. The C. acutatum isolates belonged to the intraspecific groups A2 (33%), A3 (5%), A4 (50%), A5 (3%) and A7 (6%). Differences in spore morphology, growth rate and colony colour of a selection of 146 isolates confirmed the genetic grouping. Multiple Colletotrichum genotypes were detected in the same field. There was no association between the most common genotypes and geographic origin, presence or absence of symptoms, nor plant species or plant part. Representative Belgian Colletotrichum isolates were used in pathogenicity tests, together with European and American reference isolates. The C. acutatum A2 and the Belgian C. gloeosporioides isolates were the most aggressive on fruits, followed by C. acutatum A3, A4, A5, A7 and C. coccodes isolates. When inoculated into crowns, C. acutatum A2, A5 and American C. gloeosporioides isolates were the most aggressive, followed by C. acutatum A3 isolates. The A4 and A7 isolates and all European C. gloeosporioides isolates were non‐pathogenic on crowns. These data indicate that an unusually diverse Colletotrichum population is present in Belgium. The traditional differentiation between C. acutatum and C. gloeosporioides as causal agents of fruit and crown rot, respectively, proved not to be valid in Belgian strawberry fields.

First Report of Anthracnose Caused by Colletotrichum gloeosporioides in Pumpkin in Trinidad.

In Trinidad, pumpkin (Cucurbita pepo L. and C. moschata L.) is extensively grown for local and international export markets. In November 2008, symptoms of foliar chlorosis and necrosis were observed in 15 commercial pumpkin fields located in the main production areas of St. George East, Caroni, Victoria, and St. Patrick counties. Severely infected plants were unable to support fruit maturation, which resulted in yield loss. The pathogen was isolated from surface-sterilized tissues of symptomatic plants. Colonies on potato dextrose agar (PDA) were white to cream with gray spore masses in the center. Conidia were hyaline, cylindrical with rounded ends, aseptate, and measured 12.5 to 16.5 μm × 3.5 to 5.0 μm. PCR amplification was carried out with ITS4/5 universal primers (4) and species-specific primers, CgInt/ITS4 (1), using a positive control of Colletotrichum gloeosporioides (courtesy of D. Perez-Brito). Species-specific primers generated a single amplicon, ~450 bp long, which corresponded with the positive control. The ITS1 region (1) of pumpkin isolates (GenBank No. GU320190) was 100% identical to cognate sequences of C. gloeosporioides isolates (GenBank Nos. AY841136 and FJ624257). Phylogenetic analyses (MEGA 4 - Molecular Evolutionary Genetic Analysis Software version 4 for Windows) using the neighbor-joining (NJ) algorithm placed the pumpkin isolates in a well-supported cluster (>90% bootstrap value based on 1,000 replicates) with other C. gloeosporioides isolates. The tree was rooted with C. crassipes (GenBank No. AJ536230). The pathogen was similar to C. gloeosporioides (Penz.) Penz. & Sacc. (3). In pathogenicity tests, six plants (cv. Jamaican squash) for each of five isolates were spray inoculated to runoff with a conidial suspension (1.0 × 106 conidia/ml). Negative controls were sprayed with sterile distilled water. In repeated tests, plants were symptomatic of infection 7 days postinoculation. There were no symptoms on control plants. Koch's postulates were fulfilled with the reisolation of the pathogen from symptomatic leaf tissues. Anthracnose is a serious threat to cucurbit production; however, infection is not common in pumpkin and squash (2). To my knowledge, this is the first report of C. gloeosporioides causing widespread anthracnose infection in pumpkin in Trinidad.

Genetic characterization of mango anthracnose pathogen Colletotrichum gloeosporioides Penz. by random amplified polymorphic DNA analysis

Twenty-five isolates of Colletotrichum gloeosporioides causing mango anthracnose were collected from different agroclimatic zones of India. The isolates were evaluated for their pathogenic variability on mango seedlings and genetic characterization using random amplified polymorphic DNA (RAPD molecular techniques). The random primers OPA-1, 3, 5, 9, 11, 15, 16 and 18 were used and the twenty-five isolates were grouped into two. The amplified DNA fragments (amplicons) obtained was compared by agarose gel electrophoresis. Isolate specific RAPD fingerprints were obtained. Out of eight primers in RAPD, OPA-1, 3 and 18 were able to produce reproducible banding pattern. Each of these primers generated a short spectrum of amplicons, located between 661 and 2291-bp markers, indicative of genetic polymorphism. Dendogram revealed more than 75% level of similarity. 4.36% polymorphism was also found in individual isolates that was not statistically significant (P > 0.05) among the sample, it also indicates that all the isolates tested had approximately same genetic identity. The data suggest that RAPD may be of value by virtue of its rapidity, efficiency and reproducibility in generating genetic fingerprints of C. gloeosporioides isolates. Key words: Colletotrichum gloeosporioides, genetic identification, mango anthracnose.

Genetic polymorphism and virulence of Colletotrichum gloeosporioides isolated from strawberry (Fragaria × ananassa Duchesne)

To analyze genetic relationships among Colletotrichum gloeosporioides isolates; 34 isolates were collected from strawberries all over Japan, but primarily from Chiba Prefecture, and 20 were isolated from hosts other than strawberry. These isolates were assayed for virulence on strawberries and subjected to a fingerprint (FP) analysis by repetitive extragenic palindromic-PCR. Most of the isolates that were highly virulent to strawberries had relatively similar FPs even though they were isolated from various host plants (strawberry, cyclamen, nipplefruit and Japanese pear) in different regions. A cluster analysis revealed that the highly virulent and the weakly virulent isolates tended to form individual clusters, indicating that the highly virulent strains of C. gloeosporioides, which were genetically close to isolates with similar FPs and distinguishable from the weakly virulent strains, were responsible for strawberry anthracnose in Japan.

Differentiation of Colletotrichum gloeosporioides isolates by using total proteins and esterase electrophoretic patterns and extracellular enzymes production

Isolates of Colletotrichum gloeosporioides (ISO-1, ISO-2, ISO-3, ISO-4, ISO-5 and ISO-6), the causal agent of anthracnose disease on mango fruits, were characterized by electrophoretic patterns of total proteins and esterase in polyacrylamida gel, and also, by production of extracellular enzymes on specific solid substrate. The electrophoretic analysis showed variation in number, intensity of coloration and position of the bands in the gel at each studied system tested. In contrast to the monomorphic behavior to total proteins, high esterase polymorfism was observed indicating difference among isolates. All isolates showed the activity of extracellular enzymes such as amylase, lipase, and protease with some variation among them. The proteolitic activity seemed to be more accentuated than the two other enzymes studied.

Temperature requirement of different isolates of Colletotrichum gloeosporioides isolated from mango

2 Abstract: Anthracnose caused by Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. is one of the most important diseases of mango. During survey, the disease samples of fruits affected by anthracnose were collected from Arambakam, Dapoli, Hassan, Hessarghatta, Lucknow, Raichur, Tiruvur and Tumkur and isolations were made. Studies were conducted to find out the temperature requirement of different isolates by incubating them at 15, 20, 25 28 and 30°C. The study indicated that the temperature of 25°C was found to be good for the growth of Aramkabam, Lucknow and Tiruvur isolates. Maximum growth of Dapoli, Hessarghatta and Tumkur isolates were recorded at 28°C whereas 30°C supported good growth of Hassan and Raichur isolates, nine days after inoculation. As regards to sporulation, Dapoli, Hessarghatta and Raichur isolates were good at 28°C whereas, 25°C supported good sporulation of Lucknow and Tiruvur isolates. Hassan and Tumkur isolates showed moderate sporulation at 28°C and 25°C supported moderate sporulation of Arambakam.

A phenetic analysis of <i>Colletotrichum gloeosporioides</i> isolates from selected host plants

Colletotrichum gloeosporioides is a ubiquitous fungus which infects a wide variety of plants in tropical, sub-tropical and temperate regions. This fungus accounts for substantial economic losses through out the world via both preharvest and postharvest diseases. A phenetic analysis of C. gloeosporioides isolated from Capsicum frutescens, Carica papaya, Mangifera indica, Persea americana, Ficus religiosa and Hevea brasiliensis was carried out to identify sub-specific populations. A total of 40 isolates from these six host species were used. The overall similarity among different isolates of C. gloeosporioides was determined using culture, conidial and appressorial characteristics. According to the resulting phenogram, fungal isolates had divided into two distinct groups at the initial stage separating C. papaya isolates from the rest of the isolates. The subsequent branching has lead to separation of C. gloeosporioides isolates of different hosts into distinct groups. A high degree of similarity was observed among the isolates obtained from C. frutescens, H. brasiliensis and F. religiosa. Similarly, isolates of P. americana and M. indica appear to be morphologically more similar to each other. Further, the study confirms the cross infection potential of some C. gloeosporioides isolates and the presence of host specific populations Key Words: anthracnose; phenetic analysis; cross inoculation DOI: 10.4038/cjsbs.v38i2.1859 Cey. J. Sci. (Bio. Sci.) 38 (2): 57-66, 2009

Reaction of dwarf cashew clones to Colletotrichum gloeosporioides isolates in controlled environment

The cashew (Anacardium occidentale L.) crop is an important source of income for the population of the Brazilian Northeast, and anthracnose disease caused by Colletotrichum gloeosporioides leads to significant production loss. However, there is little information on either the host resistance or the variation in the aggressiveness of the pathogen under controlled environment. The reaction of commercial (CCP-06, CCP-09, CCP-76 and CCP-1001) and one non-commercial (CAP-14) dwarf cashew clones was assessed against 36 isolates of this fungus controlled environmental conditions. All the isolates, including those from hosts other than cashew, were able to cause lesions on leaves and stems of most clones, albeit to different degrees. Clone CCP-06 was the most susceptible, while clone CCP-1001 showed a level of resistance to a number of the isolates, including isolate 905, while isolates 910 and 912 were aggressive to all clones. Injury increased the susceptibility of the clones to all isolates, indicating that resistance also might be associated with structural barriers that hinder penetration. Ripened cashew apples (8-week-old), of commercial clones were susceptible to isolates 905 and 910. Immature pseudo-fruits (2-week-old), with exception of clone CCP-76 which was susceptible to both isolates showed resistance against these isolates, suggesting the presence of structural and chemical barriers. Developed nuts (8-week-old), however, were more resistant than immature nuts (2-week-old) to both isolates, probably due to their thicker exocarp cuticle and reduced number of stomatal pores.

Benomyl sensitivity assays and species-specific PCR reactions highlight association of two Colletotrichum gloeosporioides types and C. acutatum with rumple disease on Primofiori lemons

Rumple is a serious peel collapse of Primofiori lemons in the southeast of Spain with an unresolved aetiology. Symptoms typically occur on fruits at ripening under wet conditions as dark sunken lesions producing premature fruit drop and damaged fruits unacceptable for fresh commercialization. A total of 16 Colletotrichum spp. isolates established from rumple-affected lemons collected during the autumn of 2007 from two different orchards were characterized by molecular and phenotypic assays and compared with reference isolates. Species-specific PCR reactions using β-tubulin 2 nucleotide sequences showed Colletotrichum gloeosporioides to predominate (81.5%) with limited occurrence of C. acutatum (18.75%). Among the C. gloeosporioides isolates, five (38.5%) showed benomyl resistance and eight (61.5%) were highly sensitive to the fungicide. The limited occurrence of C. acutatum could be related to factors such as the presence of both species on the same fruit, unfavourable meteorological conditions and low disease incidence. This work reveals an association of C. gloeosporioides and C. acutatum isolates with rumple disease of lemons and expands the range of C. acutatum on citrus.

Sensitivity of Colletotrichum spp. Isolated from Grapes in Korea to Carbendazim and the Mixture of Carbendazim Plus Diethofencarb

Thirty-six isolates of Colletotrichum spp. were obtained from infected grapes in two different locations of Korea; 18 isolates from Cheonahn, where carbendazim (MBC) and the mixture of MBC and diethofencarb (NPC) had been applied to control grape ripe rot, and 18 isolates from Cheongju, where no fungicides had been used. Sequences analysis of the internal transcribed spacer (ITS) and the <TEX>$\beta$</TEX>-tubulin gene identified 34 of the 36 isolates as Colletotrichum gloeosporioides. The remaining two isolates from Cheongju were identified as C. acutatum. Of the 18 isolates from Cheonahn, 12 were resistant to both MBC and the mixture (MBC+NPC), and six were sensitive to them. All C. gloeosporioides isolates from Cheongju, but not the two C. acutatum isolates, were sensitive to these fungicides. Sequence analysis of the <TEX>$\beta$</TEX>-tubulin gene in all isolates revealed that C. gloeosporioides resistant to MBC and MBC+NPC had a tyrosine instead of phenylalanine at the amino acid position 200. The appearance of resistance to MBC and the mixture in C. gloeosporioides correlated with the history of fungicide application in Korea.

PelB gene in isolates of Colletotrichum gloeosporioides from several hosts

Colletotrichum gloeosporioides is an important pathogen for a great number of economically important crops. During the necrotrophic phase of infection by Colletotrichum spp, the degradative enzymes of plant cell walls, such as pectate lyase, clearly increase. A gene pelB that expresses a pectate lyase was identified in isolates of C. gloeosporioides in avocado pathogens. Various molecular studies have identified a kind of specialization of C. gloeosporioides isolates with specific hosts; however, there have been no studies of this gene in isolates from hosts other than avocado. The same is true for other species of Colletotrichum. We examined genetic variability in order to design primers that would amplify pelB gene fragments and compared the products of this amplification in C. gloeosporioides isolates from different hosts. Genetic variability was assessed using ISSR primers; the resultant data were grouped based on the UPGMA clustering method. Primers for the pelB gene were designed from selected GenBank sequences using the Primer 3 program at an annealing temperature of 60 degrees C and product amplification of nearly 600 bp. The ISSR primers were efficient in demonstrating the genetic variability of the Colletotrichum isolates and in distinguishing C. gloeosporioides, C. acutatum and C. sublineolum species. The gene pelB was found in C. gloeosporioides, C. acutatum and C. sublineolum. Amplified restriction fragments using MspI did not reveal differences in pelB gene structure in isolates from the three different host species that we investigated.

Pathogenic diversity of avocado and mango isolates ofColletotrichum gloeosporioidescausing anthracnose and pepper spot in Australia

Colletotrichum gloeosporioides is a major fungal pathogen of avocado and mango fruit in Australia and overseas. It causes anthracnose and stem-end rot in these crops but has also been identified as the causal pathogen of pepper spot of avocado and tear stain of mango. Research was initiated to determine the pathogenic diversity of pepper spot, with emphasis on avocado. Eighty C. gloeosporioides isolates obtained from avocado and mango fruit showing anthracnose and pepper spot symptoms were screened for pathogenicity, comparative aggressiveness and cross-infection potential by inoculating onto detached avocado and mango fruit, avocado leaf petioles and branches of young, grafted nursery trees, as well as avocado fruit and pedicels still attached to the tree. On detached, ripening avocado and mango fruit in the laboratory, it was found that pepper spot isolates were as capable as anthracnose isolates of causing anthracnose lesions. However, avocado isolates were significantly (P < 0.05) more aggressive than mango isolates on avocado fruit and mango isolates were significantly (P < 0.05) more aggressive than avocado isolates on mango fruit. In field inoculations, pepper spots were formed on developing avocado fruit and pedicels on the tree. Likewise, pepper spots developed on petioles and branches of nursery avocado trees, but not on their leaves. When all isolates were grouped according to symptom or host of origin, significant differences in lesion severity were demonstrated between isolates on avocado petioles in the glasshouse, with avocado pepper spot isolates being the most aggressive, followed by avocado anthracnose isolates then mango isolates from both anthracnose and pepper spot, respectively. On unripe avocado fruit in the field, the pattern was generally similar with the mango isolates being the least aggressive. There were more and less pathogenic strains present in the pathogen populations from both mango fruit and avocado fruit but neither were restricted to anthracnose or pepper spot groupings. Generally, a higher percentage of the most aggressive isolates was from avocado pepper spot. When isolates were grouped according to the orchard of origin, there were significant differences in aggressiveness to avocado both in the glasshouse and the field.

Identification of Colletotrichum species associated with anthracnose disease of coffee in Vietnam

Twenty-three isolates of Colletotrichum gloeosporioides, five isolates of C. acutatum, two isolates of C. capsici and six isolates of C. boninense associated with anthracnose disease on coffee (Coffea spp.) in Vietnam were identified based on morphology and DNA analysis. Phylogenetic analysis of DNA sequences from the internal transcribed spacer region of nuclear rDNA and a portion of mitochondrial small subunit rRNA were concordant and allowed good separation of the taxa. We found several Colletotrichum isolates of unknown species and their taxonomic position remains unresolved. The majority of Vietnamese isolates belonged to C. gloeosporioides and they grouped together with the coffee berry disease (CBD) fungus, C. kahawae. However, C. kahawae could be distinguished from the Vietnamese C. gloeosporioides isolates based on ammonium tartrate utilization, growth rate and pathogenicity. C. gloeosporioides isolates were more pathogenic on detached green berries than isolates of the other species, i.e. C. acutatum, C capsici and C. boninense. Some of the C. gloeosporioides isolates produced slightly sunken lesions on green berries resembling CBD symptoms but it did not destroy the bean. We did not find any evidence of the presence of C. kahawae in Vietnam.

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.

Specific detection of benzimidazole resistance in Colletotrichum gloeosporioides from fruit crops by PCR-RFLP

Anthracnose diseases, caused by Colletotrichum gloeosporioides, are a worldwide problem and are especially important in Taiwan owing to the severe economic damage they cause to tropical fruits that are grown for local consumption and export. Benzimidazoles are systemic fungicides widely used for controlling these diseases in Taiwan. Thirty-one isolates of C. gloeosporioides from mango and strawberry grown in Taiwan were examined for their sensitivity to benzimidazole fungicides. The responses of the isolates grown on benzimidazole-amended culture media were characterized as sensitive, moderately resistant, resistant or highly resistant. Analysis of point mutations in the beta-tubulin gene by DNA sequencing of PCR-amplified fragments revealed a substitution of GCG for GAG at codon 198 in resistant and highly resistant isolates and a substitution of TAC for TTC at codon 200 in moderately resistant isolates. A set of specific primers, TubGF1 and TubGR, was designed to amplify a portion of the beta-tubulin gene for the detection of benzimidazole-resistant C. gloeosporioides. Bsh1236I restriction maps of the amplified beta-tubulin gene showed that the resistant isolate sequence, but not the sensitive isolate sequence, was cut. The PCR restriction fragment length polymorphism (PCR-RFLP) was validated to detect benzimidazole-resistant and benzimidazole-sensitive C. gloeosporioides isolates recovered from avocado, banana, carambola, dragon fruit, grape, guava, jujube, lychee, papaya, passion fruit and wax apple. This method has the potential to become a valuable tool for monitoring the occurrence of benzimidazole-resistant C. gloeosporioides and for assessment of the need for alternative management practices.