Colletotrichum species causing anthracnose on avocado fruit in Mexico: Current status

Colletotrichum species cause anthracnose disease in tropical and subtropical fruit crops worldwide. Mexico is the main producer and exporter of avocado (Persea americana) globally and has yearly outbreaks of anthracnose on this crop. However, which specific Colletotrichum spp. cause these outbreaks in avocado-producing regions remain uncertain; thus, the objective of the present study was to identify the species responsible. A survey performed in six production regions of Mexico yielded 232 isolates, from which a subset of 104 strains was selected based on morphological characteristics and origin. This subset was sequenced and haplotypes were analysed in the gapdh partial gene. Finally, 31 strains were identified through multilocus phylogenetic analyses using the sequences of the internal transcribed spacer region and six loci. This study revealed the presence of two species previously reported in Mexico (C. karsti and C. godetiae), three novel records in Mexico (C. siamense, C. fioriniae, and C. cigarro), four novel records on avocado (C. chrysophilum, C. jiangxiense, C. tropicale, and C. nymphaeae), and two novel lineages (Colletotrichum sp. 1 and Colletotrichum sp. 2). C. siamense was the most prevalent, while the species reported for the first time on avocado, including the novel lineages, were the least prevalent. C. karsti was the most widespread (four regions), followed by C. siamense, C. jiangxiense, and C. chrysophilum (three regions). Pathogenicity tests showed that all species caused anthracnose on avocado fruit. These findings will be useful for improving the management of avocado anthracnose outbreaks in Mexico.     

Factors influencing biological traits and aggressiveness of Colletotrichum species associated with cashew anthracnose in Brazil

Anthracnose is the main fungal disease on cashew orchards in Brazil, occurring on both vegetative and reproductive organs of cultivated and noncultivated host plants. Understanding the effect of physical and chemical exogenous factors on the biological traits of Colletotrichum spp. and determining their host range are key to developing appropriate anthracnose control measures. The present study aimed to estimate the optimum temperatures for mycelial growth, sporulation, and conidial germination of seven Colletotrichum species (C. chrysophilum, C. fragariae, C. fructicola, C. gloeosporioides, C. queenslandicum, C. siamense, and C. tropicale) associated with cashew anthracnose in Brazil. Their aggressiveness on cashew leaves and six alternative host fruits, and their sensitivity to three fungicides were also investigated. The optimum temperatures for mycelial growth, sporulation, and conidial germination ranged from about 25 to about 33°C. All Colletotrichum species induced anthracnose symptoms on wounded cashew leaves, but none of them caused lesions on intact leaf surfaces. The Colletotrichum species, except for C. fragariae and C. fructicola, were pathogenic to wounded fruits of avocado, banana, guava, mango, and papaya, and some isolates also produced lesions on nonwounded fruit tissues. No symptoms were observed on passion fruits, regardless of the inoculation method. Mycelial growth, sporulation, conidial germination, and/or appressorial formation of the seven Colletotrichum species were inhibited by azoxystrobin, difenoconazole, and thiophanate-methyl to varying degrees. The present study will contribute to the development of forecasting models based on prevailing weather of cashew cropping zones and improve cashew anthracnose management in Brazil.     

Colletotrichum species associated with chili anthracnose in Australia

Phylogenetic relationships were determined for 45 Colletotrichum isolates causing anthracnose disease of chili in Queensland, Australia. Initial screening based on morphology, ITS and TUB2 genes resulted in a subset of 21 isolates being chosen for further taxonomic study. Isolates in the C. acutatum complex were analysed using partial sequences of six gene regions (ITS, GAPDH, ACT, CHS‐1, TUB2 and HIS3), and in the C. gloeosporioides complex were analysed using four gene regions (ITS, TUB2, ApMat and GS). Phylogenetic analysis delineated four Colletotrichum species including C. siamense, C. simmondsii, C. queenslandicum, C. truncatum and a new Colletotrichum species, described here as C. cairnsense sp. nov. This is the first reported association of C. queenslandicum, C. simmondsii and C. siamense with chili anthracnose in Australia; these species were previously associated with anthracnose on papaya and avocado. Furthermore, the dominant species causing anthracnose of chili in Southeast Asia, C. scovillei, was not detected in Australia. Inoculations on chili fruit confirmed the pathogenicity of C. cairnsense and the other four species in the development of chili anthracnose in Australia.     

Phylogenetic and morphological identification of Colletotrichum boninense: a novel causal agent of anthracnose in avocado

In recent years, anthracnose has become a significant disease affecting avocado fruit in the state of Michoacan, Mexico, where it significantly reduces fruit quality and commercial yield. Anthracnose has been assumed to involve Colletotrichum gloeosporioides and C. acutatum as causal agents. However, because of the increasing incidence of anthracnose, a more precise identification of the Colletotrichum spp. involved in this disease has become desirable. During the years 2004–2007, avocado fruits of different sizes exhibiting brown‐black and reddish spots on the pericarp and soft rot in the mesocarp, were gathered from orchards in nine counties. Fungal isolates were cultured on potato dextrose agar, and among these, 31 were selected for molecular, morphological and pathogenicity analyses. The molecular approaches used sequence typing of the internal transcribed spacer region and the partial nuclear large ribosomal subunit, allowing the unequivocal identification of C. gloeosporioides (71%), C. acutatum (16%) and C. boninense (13%). This last species has not been previously reported as being associated with anthracnose symptoms in avocado fruits anywhere in the world. Various morphological characteristics such as the size and shape of conidia were determined, as well as the conidial mass colour. Pathogenicity tests performed with all three species were conducted by inoculating healthy fruits. In each case, identical symptoms developed within 3 days of inoculation. Knowledge of the Colletotrichum populations in the Michoacan state, including the newly encountered avocado pathogen C. boninense, will facilitate further studies addressing the relationships between these Colletotrichum spp. and their avocado host.     

Multilocus identification and thiophanate-methyl sensitivity of Colletotrichum gloeosporioides species complex associated with fruit with symptoms and symptomless leaves of mango

Colletotrichum spp. are known causal agents of anthracnose in a broad host range, causing severe losses. Currently, the most effective way to reduce disease is by fungicide application, which could give rise to resistant populations. This study aimed to determine the Colletotrichum species present in conventional and organic mango orchards and to evaluate their pathogenicity and sensitivity to the benzimidazole fungicide thiophanate-methyl. Seventy-one isolates from fruit with symptoms and symptomless leaves were obtained. From these, 20 representative morphotypes were analysed based on glyceraldehyde-3-phosphate dehydrogenase partial gene sequencing. A subset of 10 isolates based on different species, isolation source, and fungicide sensitivity was used for morphological and multilocus phylogenetic analysis. Colletotrichum queenslandicum was only identified in conventional production systems, C. chrysophilum only in organic systems, and C. asianum and C. siamense in both. Pathogenicity tests showed all species were pathogenic, and only C. asianum caused symptoms via both unwounded and wounded inoculation methods. Overall, 25.3% of isolates (n = 18) that belong to C. siamense, isolated from a conventional orchard, grew on thiophanate-methyl amended media at 1,000 µg/ml, suggesting high resistance. Resistance was not correlated with any common point mutations at positions 198 and 200 of the β-tubulin 2 protein, as commonly found in other fungal pathogens resistant to benzimidazole. The 74.7% remaining isolates (n = 53) belonging to the other species were sensitive, reaching 100% inhibition at <10 µg/ml. Even with benzimidazole application, anthracnose symptoms persist due to the emergence of pathogenic Colletotrichum subpopulations that are resistant to thiophanate-methyl.     

Chili anthracnose: Colletotrichum taxonomy and pathogenicity

Chili anthracnose is caused by Colletotrichum species mostly associated with the acutatum, truncatum and gloeosporioides complexes. Since 2009 the Colletotrichum taxonomy has been extensively revised based on multigene phylogenetics, which has had a large impact on the number of species known to cause anthracnose disease of chili. This review discusses (i) the taxonomy of Colletotrichum spp. infecting chili, and (ii) the impact of Colletotrichum pathotypes on breeding for resistance to anthracnose. To date, 24 Colletotrichum species have been identified as pathogens of chili anthracnose, with the three main pathogens being C. scovillei, C. truncatum and C. siamense. Identification of several pathotypes within these three Colletotrichum species, particularly pathotypes that can overcome resistance in the related Capsicum species, Ca. chinense and Ca. baccatum, will be of major concern to plant breeders as they develop resistant chili genotypes from the transfer of resistance genes from these Capsicum species into Ca. annuum. Accurate identification of the Colletotrichum species causing anthracnose and improved understanding of the biology of the Colletotrichum species and their interaction with the host will enable the application of improved integrated disease management techniques.     

Characterization and epidemiology of Colletotrichum acutatum sensu lato (C. chrysanthemi) causing Carthamus tinctorius anthracnose

In 2012, Colletotrichum isolates were collected from field‐grown safflower (Carthamus tinctorius) crops in central Italy from plants exhibiting typical anthracnose symptoms. Colletotrichum isolates were also collected from seed surfaces and from within seeds. The genetic variability of these isolates was assessed by a multilocus sequencing approach and compared with those from Colletotrichum chrysanthemi and Colletotrichum carthami isolates from different geographic areas and other Colletotrichum acutatum sensu lato‐related isolates. Phylogenetic analysis revealed that all of the strains isolated from C. tinctorius belonged to the species described as C. chrysanthemi, whereas all of the strains belonging to C. carthami had been isolated from Calendula officinalis. Phenotypic characterization of isolates was performed by assessing growth rates at different temperatures, morphology of colonies on potato dextrose agar (PDA) and the size of conidia. All C. chrysanthemi isolates from safflower had similar growth rates at different temperatures, comparable colony morphologies when grown on PDA and conidial sizes consistent with previously described C. chrysanthemi isolates. Pathogenicity tests were performed by artificially inoculating both seeds and plants and confirmed the seedborne nature of this pathogen. When inoculated on plants, C. chrysanthemi caused the typical symptoms of anthracnose on leaves. This is the first record of this pathogen on C. tinctorius in Italy, and it presents an updated characterization of Colletotrichum isolates pathogenic to safflowers in Europe.     

Aetiology of anthracnose on grapevine shoots in Brazil

Anthracnose is an important disease in vineyards in south and southeast Brazil, the main grape‐producing regions in the country. This study aimed to identify the causal agents of grapevine anthracnose in Brazil through multilocus phylogenetic analyses, morphological characterization and pathogenicity tests. Thirty‐nine Elsinoë ampelina and 13 Colletotrichum spp. isolates were obtained from leaves, stems and berries with anthracnose symptoms collected in 38 vineyards in southern and southeastern Brazil. For E. ampelina isolates, the internal transcribed spacer (ITS), histone H3 (HIS3) and elongation factor 1‐α (TEF) sequences were analysed. HIS3 was the most informative region with 55 polymorphic sites including deletions and substitutions of bases, enabling the grouping of isolates into five haplotypes. Colonies of E. ampelina showed slow growth, variable colouration and a wrinkled texture on potato dextrose agar. Conidia were cylindrical to oblong with rounded ends, hyaline, aseptate, (3.57–) 5.64 (?6.95) μm long and (2.03–) 2.65 (?3.40) μm wide. Seven species of Colletotrichum were identified: C. siamense, C. gloeosporioides, C. fructicola, C. viniferum, C. nymphaeae, C. truncatum and C. cliviae, with a wide variation in colony and conidium morphology. Only E. ampelina caused anthracnose symptoms on leaves, tendrils and stems of Vitis vinifera and V. labrusca. High disease severity and a negative correlation between disease severity and shoot dry weight were observed only when relative humidity was above 95%. In this study, only E. ampelina caused anthracnose symptoms on grapevine shoots in Brazil.     

Characteristics and distribution of Colletotrichum species in coffee plantations in Hainan,China

Anthracnose caused by Colletotrichum species is a serious disease on a range of economically important hosts. To determine the Colletotrichum species in coffee plantations in Hainan, China, 55 isolates were obtained from Coffea arabica (arabica) and C. canephora var. robusta (robusta) in five counties. Initially, partial sequences of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were used to measure fungal genetic diversity. Then a subset of 23 isolates was selected to represent the range of genetic diversity, varieties and geographic origin for further multilocus phylogenetic analyses. These isolates belong to eight known Colletotrichum species from three Colletotrichum species complexes, including gloeosporioides (C. endophytica, C. fructicola, C. ledongense, C. siamense and C. tropicale), boninense (C. karstii), gigasporum (C. gigasporum), and one singleton species (C. brevisporum). Of these, C. siamense was isolated in all sampled counties and C. fructicola was identified in three counties. The other six species were isolated only in one or two counties. Only C. siamense and C. fructicola were isolated from arabica, whereas all eight species were isolated from robusta. Occurrence of C. brevisporum, C. endophytica, C. ledongense and C. tropicale in coffee has not been reported previously. Pathogenicity tests showed that all eight species were pathogenic to coffee leaves and fruit. In vitro tests showed that Colletotrichum isolates from coffee in Hainan were most sensitive to prochloraz, less sensitive to carbendazim, propiconazole and difenoconazole, and least sensitive to myclobutanil.     

Most Colletotrichum species associated with tree tomato (Solanum betaceum) and mango (Mangifera indica) crops are not host‐specific

An important constraint for crop production in Colombia is the high incidence of anthracnose caused by Colletotrichum species. Although several studies have focused on these fungi, the relationship between the different fungal species within the genus and their hosts and whether they display any host preference or host specificity has yet to be examined. In Colombia, diseases caused by Colletotrichum species are particularly severe in mango (Mangifera indica) and tree tomato (Solanum betaceum) crops. In a previous investigation, the Colletotrichum phylogenetic species attacking these crops were identified. The present study aimed to determine whether isolates collected from tree tomato and mango showed host preference or host specificity by assessing aggressiveness, spore density, latent period, and fitness of each strain on the two hosts. In the departments of Cundinamarca and Tolima, Colombia, isolates were collected from plants that presented typical anthracnose symptoms and were identified as C. acutatum, C. asianum, C. boninense, C. gloeosporioides, C. tamarilloi and C. theobromicola. Inoculation of conidia of each isolate onto both hosts showed isolates had no host preference and only the C. gloeosporioides isolate showed host specificity. However, in general, isolates produced a higher spore density when inoculated on the alternate host, which may indicate a difference in the degree of adaptation to each host. Statistical analyses of the assessed parameter values revealed that isolates use different infection strategies when infecting each host. In light of these results, the implications of using quantitative estimations of fitness when studying fungal pathogens are discussed.     

Lack of host specificity of Colletotrichum spp. isolates associated with anthracnose symptoms on mango in Brazil

The aim of the present study was to analyse the genetic and pathogenic variability of Colletotrichum spp. isolates from various organs and cultivars of mango with anthracnose symptoms, collected from different municipalities of São Paulo State, Brazil. Colletotrichum gloeosporioides isolates from symptomless citrus leaves and C. acutatum isolates from citrus flowers with post‐bloom fruit drop symptoms were included as controls. Sequencing of the ITS region allowed the identification of 183 C. gloeosporioides isolates from mango; only one isolate was identified as C. acutatum. amova analysis of ITS sequences showed larger genetic variability among isolates from the same municipality than among those from different populations. fAFLP markers indicated high levels of genetic variability among the C. gloeosporioides isolates from mango and no correlation between genetic variability and isolate source. Only one C. gloeosporioides mango isolate had the same genotype as the C. gloeosporioides isolates from citrus leaves, as determined by ITS sequencing and fAFLP analysis. Pathogenicity tests revealed that C. gloeosporioides and C. acutatum isolates from either mango or citrus can cause anthracnose symptoms on leaves of mango cvs Palmer and Tommy Atkins and blossom blight symptoms in citrus flowers. These outcomes indicate a lack of host specificity of the Colletotrichum species and suggest the possibility of host migration.     

A quantitative real‐time PCR assay for detection of Colletotrichum lindemuthianum in navy bean seeds

Bean anthracnose is a seedborne disease of common bean (Phaseolus vulgaris) caused by the fungal pathogen Colletotrichum lindemuthianum. Using seed that did not test positive for the pathogen has been proven to be an effective strategy for bean anthracnose control. To quantify the extent of anthracnose seed infection, a real‐time PCR‐based diagnostic assay was developed for detecting C. lindemuthianum in seeds of the commercial bean class navy bean. The ribosomal DNA (rDNA) region consisting of part of the18S rDNA, 5^.8S rDNA, internal transcribed spacers (ITS) 1, 2 and part of the 28S rDNA of seven races of C. lindemuthianum, 21 isolates of Colletotrichum species and nine other bean pathogens were sequenced with the universal primer set ITS5/ITS4. Based on the aligned sequence matrix, one primer set and a probe were designed for a SYBR Green dye assay and a TaqMan MGB (minor groove binder) assay. The primer set was demonstrated to be specific for C. lindemuthianum and showed a high sensitivity for the target pathogen. The detection limit of both assays was 5 fg of C. lindemuthianum genomic DNA. To explore the correlation between the lesion area and the DNA amount of C. lindemuthianum in bean seed, seeds of the navy bean cultivar Navigator with lesions of different sizes, as well as symptomless seeds, were used in both real‐time PCR assays.     

Colletotrichum falcatum and Fusarium species induce symptoms of red rot in sugarcane in Brazil

Red rot is an important disease of sugarcane, reported from the main producing countries of the crop. The main causal agent is Colletotrichum falcatum, which induces reddish internal stalk rot, resulting in loss of quality and quantity of sugars. While the occurrence of this disease has been reported in plantations in Brazil, the aetiology of the disease is not yet fully understood. We isolated and identified the fungi associated with sugarcane plants showing symptoms of red rot. Thirty isolates were recovered and grouped by morphology within the genera Colletotrichum and Fusarium. Based on phylogenetic analyses of DNA sequences from ITS, ACT, SOD, GAPDH, and EF-1α, eight isolates were identified as C. falcatum (n = 6) and C. plurivorum (n = 2). Twenty-two isolates belonged to the Fusarium fujikuroi species complex and were identified as F. sacchari (n = 8), F. proliferatum (n = 3), and F. madaense (n = 11). Coinfection with C. falcatum and Fusarium species were frequently observed. C. falcatum and Fusarium strains induced reddening of internal tissues and stalk rot in sugarcane plants, symptoms of red rot, while Fusarium species also induced symptoms of pokkah boeng. C. plurivorum, whose sexual stage was observed on the surface of stems, did not induce stalk rot or leaf symptoms. The results obtained in this study clarify the aetiological agents of red rot of sugarcane in Brazil. The conditions that lead to the development of specific symptoms of red rot or pokkah boeng are under investigation.     

Identification and characterization of Colletotrichum species associated with anthracnose disease of banana

Banana (Musa spp.) is one of the five most abundantly produced fruits in the world and is widely planted in tropical and subtropical areas. Banana anthracnose is one of the main diseases during the growth and postharvest storage period of banana, seriously affecting quality and production. In this study, 24 samples of banana anthracnose were collected near the cities Nanning, Qinzhou, Baise, and Chongzuo in Guangxi Province, China. Based on colony features, conidial and appressorial morphology, and sequence analysis of several genomic regions (internal transcribed spacer [ITS] region, glyceraldehyde-3-phosphate dehydrogenase [GAPDH], actin [ACT], β-tubulin [TUB2], chitin synthase [CHS-1], calmodulin [CAL], and the intergenic region of apn2 and MAT1-2-1 [ApMAT]), the 32 Colletotrichum isolates obtained were identified as five species: C. fructicola (41%), C. cliviicola (28%), C. siamense (16%), C. karstii (9%), and C. musae (6%). A conidial suspension (10⁶ spores/ml) was used to inoculate banana seedlings for pathogenicity tests by applying 20 μl to wound sites. Lesions caused by C. musae developed most rapidly while those of C. karstii took the longest time to develop. This is the first report of C. siamense, and C. karstii associated with banana anthracnose in China, and the first report of C. fructicola and C. cliviicola associated with banana anthracnose worldwide.     

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.     

Markers to differentiate species of anthracnose fungi identify <Emphasis Type="Italic">Colletotrichum fructicola</Emphasis> as the predominant virulent species in strawberry plants in Chiba Prefecture of Japan

Colletotrichum fungi belonging to the Colletotrichum gloeosporioides species complex include a number of economically important postharvest pathogens that often cause anthracnose. Until now, different species within this group could only be distinguished from one another reliably using multigenic phylogenetic analyses. Using a comparative genomics approach, we developed a marker that can differentiate Colletotrichum fructicola, Colletotrichum aenigma and Colletotrichum siamense within the C. gloeosporioides species complex based on PCR amplicon size differences. When we used this marker to classify 115 isolates collected over 20 years from strawberries in Chiba Prefecture, Japan, the isolates were predominantly C. fructicola. To our knowledge, this is the first report characterizing different species of Colletotrichum infecting strawberries in Japan and contributes to our understanding on the diversity of anthracnose pathogens in Japan.     

Pathogenicity of Colletotrichum species causing anthracnose of Capsicum in Asia

Anthracnose of chili is caused by a complex of Colletotrichum species, with recent surveys reporting at least 28 different species implicated. However, there have been very few studies to identify the relative pathogenicity of the various species or to optimize a bioassay to assess pathogenicity. A detached Capsicum fruit bioassay to determine the pathogenicity of a diverse geographical range of isolates of Colletotrichum scovillei showed fruit maturity, host genotype, and inoculation method all interact to affect infection and rate of lesion development. On Capsicum annuum ‘Bangchang’ fruit wounded prior to inoculation, pathogenicity was consistent regardless of fruit maturity. In contrast, without wounding there was variability in pathogenicity. On the relatively resistant host Capsicum chinense PBC932, pathogenicity was dependent on both the inoculation method and the maturity stage of the fruit. In addition, lack of correlation in pathogenicity of isolates between the two Capsicum lines indicated that there was host–isolate specialization that would make prediction of pathogenicity of isolates on host difficult. In a further study, 10 species of Colletotrichum isolated from diseased chili fruits in Asia caused anthracnose symptoms on C. annuum ‘Bangchang’ under all testing conditions, with large differences in aggressiveness. C. chinense PBC932 was generally more resistant to all the species, with smaller lesions produced in different host conditions. Colletotrichum javanense and C. scovillei were highly aggressive relative to other species, especially when inoculated on nonwounded fruit. Pathotype differences were identified within multiple isolates of C. scovillei and C. siamense, the two most frequently identified pathogenic species on chili.     

Colletotrichum species causing grape ripe rot disease in Vitis labrusca and V. vinifera varieties in the highlands of southern Brazil

Ripe rot is one of the most important bunch diseases of grapes in the highlands of southern Brazil and a matter of concern for winegrowers. Sixty-one strains isolated from berries of Vitis labrusca and V. vinifera varieties with symptoms were classified by phylogenetic analysis of the sequences of β-tubulin, glyceraldehyde-3-phosphate dehydrogenase, D1/D2 domain of 28S rDNA, and rDNA internal transcribed spacer. They were also characterized by morphology, and their pathogenicity was evaluated. The combined molecular data allowed identification of six Colletotrichum species: C. fructicola, C. kahawae and C. viniferum (gloeosporioides complex), C. limitticola, C. nymphaeae (acutatum complex), and C. karstii (boninense complex). This is the first report of C. karstii and C. limitticola associated with the ripe rot of grapes. Morphological characteristics varied within and among species, confirming their separation at the complex level. Pathogenicity tests on V. vinifera berries showed that the most prevalent species, C. viniferum (37.8%) and C. fructicola (36.1%), were more virulent than the less prevalent species C. limitticola and C. karstii. Our findings indicate that there is a high diversity of Colletotrichum species associated with ripe rot disease of grapes in Brazil. There were no clear differences in the distribution of Colletotrichum species between V. labrusca and V. vinifera varieties. The determination of fungal species responsible for grape ripe rot in Brazilian vineyards may contribute to further epidemiological studies and the development of more efficient prophylactic methods for ripe rot management.     

Species of the Colletotrichum gloeosporioides and C. boninense complexes associated with olive anthracnose

The taxonomic status of Colletotrichum gloeosporioides sensu lato (s.l.) associated with olive anthracnose is still undetermined and the pathogenic ability of this species complex is controversial. In the present study, isolates obtained from olive and provisionally identified as C. gloeosporioides s.l. on the basis of morphological and cultural features were reclassified using ITS and TUB2 as DNA barcode markers and referred to seven distinct species, recently separated within C. gloeosporioides (C. aenigma, C. gloeosporioides sensu stricto (s.s.), C. kahawae, C. queenslandicum, C. siamense and C. theobromicola) and C. boninense (C. karstii) species complexes. Furthermore, isolates of C. kahawae were ascribed to the subspecies ciggaro by analysing the GS gene. A single isolate, not in either of these two species complexes, was not identified at the species level. In pathogenicity tests on detached olive drupes some of these species, including C. aenigma, C. kahawae subsp. ciggaro, C. queenslandicum, C. siamense and C. karstii, were shown to be weakly pathogenic. Moreover, they were found very sporadically on olive. In contrast, some isolates of C. gloeosporioides s.s. and isolates of C. theobromicola proved to be virulent on both green and ripening olives. This study gives a better insight into both the aetiology and the epidemiology of olive anthracnose and might have implications for biosecurity and quarantine because C. theobromicola has never been reported in major European olive‐producing countries.     

云南葡萄产区葡萄炭疽病病原鉴定及致病力分析

为了明确引起云南葡萄产区炭疽病的病原种类,利用形态鉴定和特异性引物分子检测相结合的方法对从云南省主要葡萄产区采集的60株炭疽病菌菌株进行了鉴定。葡萄炭疽病菌菌株的菌落形态和生长速率与对照菌株尖孢炭疽菌Colletotrichum acutatum差异不明显,但其分生孢子大小显著小于尖孢炭疽菌,附着胞深褐色,球形或不规则形。胶孢炭疽菌Colletotrichum gloeosporioides特异性引物CgInt/ITS4从供试葡萄炭疽病菌菌株基因组DNA中扩增出1条约500 bp的特异性条带,而尖孢炭疽菌特异性引物CaInt2/ITS4对葡萄炭疽病菌无扩增条带。研究表明,引起云南葡萄主产区炭疽病的病原为胶孢炭疽菌;供试胶孢炭疽菌对红提葡萄均有致病力,但菌株致病力差异较大,对番茄和草莓存在交叉侵染的能力,且对多菌灵的敏感性较尖孢炭疽菌高。