Isolates Of Colletotrichum Gloeosporioides Research Articles

Morphological and Molecular Diversity of Colletotrichum gloeosporioides Causing Yam (Dioscorea alata L.) Anthracnose Disease in Côte d’Ivoire

Yam is a plant of great importance for the Ivorian people in terms of food, nutrition, economy, and socio-cultural value. However, its production is threatened by several biotic factors, including anthracnose, one of the most destructive diseases affecting yams. The objective of this study was to assess the morphological and molecular diversity of Colletotrichum gloeosporioides isolates responsible for anthracnose in yam (Dioscorea alata) in Côte d'Ivoire. Twenty-seven previously isolated strains were collected from Plant Health Laboratory of Nangui ABROGOUA University and analyzed. The study examined the cultural (coloration, growth mode, texture, and colony diameter), microscopic (conidial shape, size, and spore concentration), and molecular characteristics of these isolates. Significant morphological diversity was observed among the isolates. Macroscopically, three major groups were identified based on colony coloration (whitish, orange, and grayish). Colony textures varied, presenting cottony, flaky, downy, or filamentous appearances, with growth patterns ranging from concentric and radiating to regular rings. Colony diameters ranged from 37 mm to 82 mm. Microscopically, sporulation varied significantly among isolates, ranging from 1.1 × 10⁵ to 85.4 × 10⁵ spores, as did conidial size, which ranged from 10.54 to 19.29 µm in length and 3.93 to 6.43 µm in diameter. Molecular analysis through comparison with GenBank nucleotide sequences revealed homology rates of 99-100% and varying proximities between the rDNA sequences of the isolates. In conclusion, the characterization of these isolates provides valuable insights for improving disease control strategies for yam anthracnose.

Isolation and Characterization of the Incitant of Leaf Spot of Turmeric and in-vitro Efficacy of Native Isolate of Endophytic Bacteria

Turmeric, Curcuma longa L. is an important commercial spice crop cultivated in Meghalaya covering 2,649 ha area with 16,497 MT productions. However, the turmeric cultivation is severely affected by leaf spot disease limiting its yield. So, the present study was conducted to identify the pathogen associated with leaf spot disease of turmeric as well as to check the efficiency of bacterial endophytes in managing the disease. Based on the morphological and cultural studies, six isolates of Colletotrichum gloeosporioides were identified as the causal organism of leaf spot disease of turmeric. The isolates on PDA medium produced white to grey fluffy (raised/ flat) cottony culture with serrated margin. All the isolates produced dark brown acervuli and globular conidia with oil globules inside. Five bacterial endophytes viz., BE 1, BE 222, M1W1, NGB21 and SVC 11 were tested against C. gloeosporioides by using dual culture assay. They were able to inhibit the mycelial growth of C. gloeosporioides in the range of 35.82-68.11%. The highest percent inhibition in dual culture assay was recorded in the isolate NGB 21 (68.11%) followed by isolate BE1 (59.89%).

Sensitivity to fungicides in isolates of Colletotrichum gloeosporioides and C. acutatum species complexes and efficacy against anthracnose diseases

Colletotrichum species cause diseases on many plants and are among the ‘top 10’ fungal plant pathogens. Species of the C. gloeosporioides and C. acutatum complexes are particularly important because they infect temperate fruit crops, but their control relies largely on chemical fungicides. In this study, differences in intrinsic fungicide sensitivity were determined in vitro using isolates of the C. gloeosporioides sp. complex (C. fructicola, C. siamense, and C. tropicale) and the C. acutatum sp. complex (C. fioriniae and C. nymphaeae), which had never been exposed to fungicides. Mycelial growth of all isolates was sensitive to the QoI azoxystrobin, the SDHI benzovindiflupyr, and the new DMI fungicide mefentrifluconazole. The isolates of C. nymphaeae were highly sensitive to the phenylpyrrole fungicide fludioxonil. The isolates of C. gloeosporioides sp. complex were sensitive to the bis-guanidine fungicide iminoctadine-albesilate, whereas those of C. acutatum sp. complex were inherently insensitive. These results are valuable when sensitivity of field populations is monitored in resistance management. Although SDHI fungicides are largely not effective against diseases caused by Colletotrichum species, benzovindiflupyr controlled anthracnose disease of various crops such as kidney bean, garland chrysanthemum, and strawberry, caused by C. lindemuthianum, C. chrysanthemi, and C. siamense, respectively, demonstrating this fungicide to be unique among SDHIs and having a broad control spectrum against anthracnose. To help understanding the reason for differential activity of benzovindiflupyr and boscalid, sdhB gene sequences were analyzed but those of C. lindemuthianum, C. chrysanthemi, and C. scovillei revealed no known mutations reported to be responsible for SDHI resistance in other fungi, indicating that other mechanism(s) than target-site modification may be involved in differential sensitivity to benzovindiflupyr and boscalid, found in Colletotrichum species.

Occurrence and infective potential of Colletotrichum gloeosporioides isolates associated to Citrus limon var Eureka

A collection of 37 fungi associated to Italian lemon plants with disease symptoms, was obtained. Ten genera including Aspergillus, Alternaria, Nigrospora, Lasiodiplodia, Dothideomycetes, Pleurostoma, Setosphaeria, Penicillium, Fusarium and Colletotrichum were identified by using ITS1–5.8S–ITS2, D1/D2 26S and COX1 loci. The last three genera were abundant on the damaged fruits, being Colletotrichum the more abundant (32.4 %). CaInt2 and CgInt primers support the identity of these isolates as C. gloeosporioides. Variability, inferred by rep-PCR and multilocus sequence analysis shows genetic differences among the C. gloeosporioides isolates. Infective profile evaluated in Colletotrichum isolates shows different leave infection percentages (26 to 60 %). SEM analysis showed mycelium, spores and appressoria on the leaves of selected Colletotrichum isolates. Specifically, the AL-05 and AL-13 isolates showed a high chitin deacetylase activity (CDA) peaking at 1.2 U/mg protein in AL-13. This is the first report on C. gloeosporioides infecting Italian lemon leaves in Mexico.

Cytological aspects of compatible and incompatible interactions between cashew (Anacardium occidentale L.) seedlings and isolates of Colletotrichum gloeosporioides (Penz.) complex

Abstract A strategy in the control anthracnose of cashew (Anacardium occidentale L.) is the management of crop phenology and defense mechanisms of this host. In previous studies, under controlled conditions, the seedling reactions of 5 cashew clones (CAP-14, CCP-06, CCP-09, CCP-76 and CCP-1001) to 36 isolates of Colletorichum gloeosporioides Penz. complex (LARS- 905 to 940) was evaluated. However, good field management requires information about the infection process. This research aimed to clarify cytophysiological aspects of three compatible interactions of this pathosystem (isolates LARS-905 and 910 × CCP-76; LARS-910 × CCP-1001) and an incompatible one (LARS-905 × CCP-1001), using infected leaves/stems and microscopy (light, scanning and transmission electron). No significant differences were found prior to penetration. In the susceptible combinations, 36-66 h after inoculation, a thin primary hypha (TPH) formed in the invaded epidermal cell, widening as a large primary hypha (LPH), which filled the cell lumen simultaneously with accumulation of of yellow-brown lignopolysaccharides. Then, a thin secondary hypha (TSH) developed from the LPH, penetrating adjacent cells before the first became necrotic. In the incompatible interaction, the response of the first invaded cell was faster and more intense, with formation of papilla and lignopolysaccharide-protein-silicon complex usually blocking the pathogen.

In vitro and in vivo, biocontrol activity of extracts prepared from Egyptian indigenous medicinal plants for the management of anthracnose of mango fruits

Anthracnose is a very restrictive disease disturbing production, as well as postharvest property of mango fruit in Egypt. Fifteen isolates of Colletotrichum gloeosporioides were recovered from mango fruits displayed anthracnose symptoms. PCR assay was achieved in addition to morphological study confirmed that the causative agent of anthracnose in mango fruits is C. gloeosporioides. Anthracnose control of mango fruits by plant extracts was verified. Both ethanol and aqueous extracts prevented the growth of the pathogen in some degrees in vitro. Aqueous and ethanol extracts of Plantago sinaica were the strongest on fungal growth than other plants. A qualitative phytochemical investigation of plant extracts from testing plants designated saponins, flavonoids, alkaloids, tannins, and phenols. Plantago sinaica extract exhibited a higher amount of phenolic compounds than other plants. Analysis of phenolic compounds of Plantago sinaica extract using HPLC showed that ellagic acid represented the highest quantity than other compounds. Electron microscopy showed changes in the ultrastructure of the pathogen hyphae after treatment by Plantago sinaica extract.

English

Anthracnose disease is a major constraint to yam production in tropical West Africa and anywhere the crop is cultivated. This study determined the cultural characteristics and growth rates of mycelia and also characterised 6 isolates of Colletotrichum gloeosporioides, the causal agent of the yam anthracnose disease, obtained from Dioscorea rotundata leaves, vines and setts in the Tolon District of Ghana. The cultural characteristics and mycelial growth rates of the isolates were determined on Potato Dextrose Agar (PDA). The C. gloeosporioides isolates were characterised using polymerase chain reaction technique with the universal primer pairs ITS1/ITS4 and NS1/NS2, C. gloeosporioides species specific primer pairs CgInt/ITS4 and CgLac-f/CgLac-r, and C. acutatum species specific primer pairs CaGlu-f1/CaGlu-r1 and Ca-f1/Ca-r1. Based on the PCR, six isolates of C. gloeosporioides with distinct cultural characteristics were obtained. There were no significant differences (P ≤ 0.05) in mycelial growth rates among the isolates. The C. gloeosporioides isolates produced characteristic band sizes on ITS1/ITS4, NS1/NS2, CgInt/ITS4 and CgLac-f/CgLac-r. None of the isolates produced a band on CaGlu-f1/CaGlu-r1 and Ca-f1/Ca-r1. The proper identification of C. gloeosporioides, the pathogen responsible for the D. rotundata anthracnose is important for the proper management of the disease.   Key words: Anthracnose disease, cultural characteristics, DNA band, morphological characteristics, Mycelial growth rate, polymerase chain reaction (PCR).

Colletotrichum acutatum complex causing anthracnose on peach in Brazil

Anthracnose, caused by Colletotrichum spp., has caused damage and great losses in peach orchards in two Brazilian states, Santa Catarina (SC) and Sao Paulo (SP). There is limited information on the characterization of Colletotrichum spp. from those locations. In this study we characterized Colletotrichum spp. isolated from peach fruit from SC and SP, and compared them to a reference isolate of Colletotrichum gloeosporioides, using molecular and traditional tools. Molecular analysis revealed that all isolates (7) belong to C. acutatum species complex (Cac) and three of them are C. nymphaeae. Most of the isolates showed distinct characteristics among them for most of the variables assessed using traditional methods. The optimum temperature for mycelial growth ranged from 24 to 26 °C, for conidial germination it ranged from 22.7 to 24.6 °C, and for germ tube length the temperature ranged from 21.3 to 27.3 °C. Disease severity caused by the Cac isolates was similar when compared wounded and nonwounded fruits. The PrpCnSP13–19 isolate was the most aggressive. More severe anthracnose symptoms were observed in fruits inoculated and maintained at simulated temperatures of Sao Paulo state when compared to fruits inoculated and maintained at simulated temperatures of the states of Parana, Santa Catarina and Rio Grande do Sul. Our results suggest that there are different strains of Cac, with different level of aggressiveness and optimum temperatures for disease development.

Exoenzymes as a pathogenicity factor for Colletotrichum gloeosporioides associated with coffee plants

ABSTRACT Phytopathogenic fungi during the penetration and colonization process are capable of secreting several enzymes, which enable infection of the host live tissue, acting on the degradation of wax, cuticle and cell walls. The ability of a pathogenic agent to produce enzymes or not can determine the severity degree of a disease. In this study, 33 isolates of Colletotrichum gloeosporioides related to anthracnose and blister spot on coffee trees were evaluated for their ability to produce hydrolytic enzymes (amylase, lipase, protease, laccase, pectinase and cellulase) and specific cell wall degrading enzymes “CWDEs” (polygalacturonase, polymethylgalacturonase and pectin-lyase), as well as their relationship with the pathogenicity/aggressiveness of isolates. For all isolates of C. gloeosporioides, extracellular enzymes could be detected, except cellulases. Isolates I-9 and I-24 produced the highest levels of extracellular enzymes, as well as CWDEs. They also had the highest disease intensity indexes, suggesting a relationship between enzymes and aggressiveness of the isolates.

Strategic eco-friendly management of post-harvest fruit rot in papaya caused by Colletotrichum gloeosporioides

Papaya (Carica papaya L.) is one of the important fruits cultivated in the tropical and subtropical regions are widely prone to the post-harvest anthracnose disease. A sum of ten isolates of Colletotrichum gloeosporioides were collected and identified through morphological and molecular method. Morphological characterization of the isolates revealed a wide variation among the isolates with respect to colony colour, topography, margin, pigmentation and zonation. The ITS gene region and the specific primer, MKCgF coupled with ITS-4, which generated amplicons of size 560 bp and 380 bp respectively for C. gloeosporioides. The amplicon (560 bp) of virulent strain Cg1 was partially sequenced [MF062699]. In order to formulate eco-friendly management practices, the in vitro screening of different biocontrol agents viz., Bacillus spp., Pseudomonas spp., plant extracts and essential oils were tested against the C. gloeosporioides. Based on the in vitro efficacy, Bacillus sp. (BSP1) and cinnamon oil were selected and further tested under field conditions as pre harvest spray and after harvest as fruit dipping. The experimental results revealed that pre-harvest spray with Bacillus sp. (BSP1) (5%) + post-harvest dipping with cinnamon oil (0.1%) recorded the lowest PDI of 3.25 when compared to control (70.36) and also increased the shelf life of papaya fruits up to 14 days. Our results show that this novel methodology of use a combination of biocontrol agent as pre-harvest spray and essential oils as post-harvest fruit dipping will protect against post-harvest anthracnose of papaya and use of chemical fungicides can be avoided.

Comparative pathogenicity of Colletotrichum spp. against different varieties of strawberry plants (Fragaria ananassa) widely grown in Morocco

The evolution of anthracnose symptoms on the aerial part (leaves, stems and strawberries) of three varieties Fortuna, Camarosa and Festival of strawberry plants inoculated with the conidial suspensions of Colletotrichum acutatum and Colletotrichum gloeosporioides isolates was followed. The severity index and infection coefficients increased in function of time. Seven days after inoculation they were low not exceeding 13.43% and 43.33, but they increased four weeks after inoculation, respectively, to 37.96% and 99 on strawberry plants of the Camarosa variety, 54.44% and 105 on those of Fortuna and 51.12% and 85 on those of Festival. At the sixth week, the severity index and infection coefficients became very high, reaching respectively 100% and 408 on Fortuna plants inoculated with C. gloeosporioides isolate (Coll3) followed by Coll2 (89.28% – 300), Coll1 (86.66% – 378) and Coll4 (80.45% – 198) of C. acutatum species. Similarly, the isolate Coll3 caused fruit rot; the percentage of rotten strawberries was 100% on Fortuna variety, 83.33% on Festival and 70.25% on Camarosa. A positive re-isolation of the tested Colletotrichum isolates has been noted from leaves of strawberry varieties and negative from crowns or the roots. A significant to moderate reduction in fresh and dry weights of the aerial part and roots was noted in inoculated strawberry plants compared to the control.

English

Twenty six isolates of Colletotrichum gloeosporioides from anthracnose infected mango fruits were isolated from different places of Tamil Nadu, India and these isolates were identified as C. gloeosporioides by Internal transcribed spacer (ITS) and species specific (CgInt) primers. The sensitivity of C. gloeosporioides isolates to benomyl fungicide were evaluated at five different concentrations viz., 0.5, 1, 2, 5, 10 mg/l through poisoned food technique and were expressed very less to highly sensitiveness to the fungicide. All the twenty six isolates were able to grow at the lowest concentration of 0.5 mg/l benomyl amended medium and the average mycelial growth was 70.70 mm at even days after inoculation. At the highest concentration of 10 mg/l benomyl, only two isolates viz., MCG 7 and 16 were able to grow with the mycelial diameter of 12.00 and 18.00 mm, respectively and 100% inhibition was found in the remaining isolates. In addition, benzimidazole sensitive and resistance β - tubulin gene sequences of TUB 1 and TUB2 were amplified from the benomyl sensitive isolates of C. gloeosporioides. The results indicated the differential resistance or sensitivity to benomyl fungicide against C. gloeosporioides and thereby allowed to identify the variability and diversity of the isolates on regional basis.   Key words: Mango, C. gloeosporioides, benomyl sensitive, β - tubulin gene.

Production of cell wall degrading enzymes by Colletotrichum loeosporioides causing mango anthracnose

Mango (Mangifera indica L.), is infected by different fungal pathogens, among them anthracnose is the most serious fungal disease and is caused by Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. It produces cell wall degrading enzymes viz., polygalacturonase and pectin methyl esterase. The activity of these cell wall degrading enzyme was assayed. The virulent isolates of Colletotrichum gloeosporioides produced more pectinolytic enzymes and their activity increased with the increase in age of the culture.

Selection of entomopathogenic fungus for biological control of chili anthracnose disease caused by Colletotrichum spp.

The literature on the entomopathogenic fungi in the genus Cordyceps describing its use in the agricultural area as a biocontrol agent is limited. In this study, a total of 47 isolates of entomopathogenic fungi were isolated from dead cicada nymphs obtained from various locations in the northeast of Thailand. These isolates were primarily screened for antagonistic activity to inhibit the mycelial growth of one isolate of Colletotrichum gloeosporioides and one isolate of C. capsici. The screen revealed that five isolates of entomopathogenic fungi showed good inhibitory effects on the fungal mycelial growth and were chosen for further confirmation of their antagonistic effects against five isolates of C. gloeosporioides and five isolates of C. capsici by the dual culture method. After investigation, the isolate Cod-NB1302 had the best inhibitory effect. Moreover, the mycelium extract and culture filtrate of isolate Cod-NB1302 also had inhibitory effects on the mycelial growth and conidial germination of all isolates of plant pathogenic Colletotrichum spp. under in vitro conditions. Interestingly, the mycelium extract and culture filtrate effectively reduced the size of the disease lesion and disease severity on chili fruits after inoculation with the plant pathogenic fungi. However, the mycelium extract exhibited greater antifungal activity than the culture filtrate. Finally, the isolate Cod-NB1302 was identified as Ophiocordyceps sobolifera based on the sequence of three ribosomal nuclear DNA genes and two protein-coding genes. These findings suggest that the isolate Cod-NB1302 is a potential candidate, with antagonistic activity, for use as a source of antifungal agents to control anthracnose disease caused by the plant pathogenic Colletotrichum spp.

ストロビルリン系薬剤耐性マンゴー炭疽病菌<i>Colletotrichum gloeosporioides</i>の発生

Sensitivity to strobilurin fungicides was tested for 107 isolates of Colletotrichum gloeosporioides, obtained in 2009 and 2010 from mangoes with anthracnose in Okinawa Prefecture, Japan. When isolates were grown on potato dextrose agar containing 1000 ppm of salicylhydroxamic acid and various concentrations of azoxystrobin and kresoxim-methyl, two strains showed a minimal inhibitory concentration of >3000 ppm and were regarded as resistant. The control efficacy of azoxystrobin against two strains was low in a leaf bioassay, and the G143A point mutation in the cytochrome b gene, conferring resistance to strobilurins, was confirmed by PCR-RFLP using restriction enzyme Fnu4HI.

First Report of Leaf Spot Disease Caused by Colletotrichum gloeosporioides on Chinese Bean Tree in China.

Chinese bean tree, Catalpa fargesii f. duciouxii (Dode) Gilmour, is an ornamental arbor plant. Its roots, leaves, and flowers have long been used for medicinal purposes in China. During July 2010, severe outbreaks of leaf spot disease on this plant occurred in Kunming, Yunnan Province. The disease incidence was greater than 90%. The symptoms on leaves began as dark brown lesions surrounded by chlorotic halos, and later became larger, round or irregular spots with gray to off-white centers surrounded by dark brown margins. Leaf tissues (3 × 3 mm), cut from the margins of lesions, were surface disinfected in 0.1% HgCl2 solution for 3 min, rinsed three times in sterile water, plated on potato dextrose agar (PDA), and incubated at 28°C. The same fungus was consistently isolated from the diseased leaves. Colonies of white-to-dark gray mycelia formed on PDA, and were slightly brown on the underside of the colony. The hyphae were achromatic, branching, septate, and 4.59 (±1.38) μm in diameter on average. Perithecia were brown to black, globose in shape, and 275.9 to 379.3 × 245.3 to 344.8 μm. Asci that formed after 3 to 4 weeks in culture were eight-spored, clavate to cylindrical. The ascospores were fusiform, slightly curved, unicellular and hyaline, and 13.05 to 24.03 × 10.68 to 16.02 μm. PCR amplification was carried out by utilizing universal rDNA-ITS primer pair ITS4/ITS5 (2). Sequencing of the PCR products of DQ1 (GenBank Accession No. JN165746) revealed 99% similarity (100% coverage) with Colletotrichum gloeosporioides isolates (GenBank Accession No. FJ456938.1, No. EU326190.1, No. DQ682572.1, and No. AY423474.1). Phylogenetic analyses (MEGA 4.1) using the neighbor-joining (NJ) algorithm placed the isolate in a well-supported cluster (>90% bootstrap value based on 1,000 replicates) with other C. gloeosporioides isolates. The pathogen was identified as C. gloeosporioides (Penz.) Penz. & Sacc. (teleomorph Glomerella cingulata (Stoneman) Spauld & H. Schrenk) based on the morphological characteristics and rDNA-ITS sequence analysis (1). To confirm pathogenicity, Koch's postulates were performed on detached leaves of C. fargesii f. duciouxii, inoculated with a solution of 1.0 × 106 conidia per ml. Symptoms similar to the original ones started to appear after 10 days, while untreated leaves remained healthy. The inoculation assay used three leaves for untreated and six leaves for treated. The experiments were repeated once. C. gloeosporioides was consistently reisolated from the diseased tissue. C. gloeosporioides is distributed worldwide causing anthracnose on a wide variety of plants (3). To the best of our knowledge, this is the first report of C. gloeosporioides causing leaf spots on C. fargesii f. duciouxii in China.

Characteristics and Control of Colletotrichum gloeosporioides Isolates in Behera Governorate, Egypt

Eight isolates of Colletotrichum gloeosporioides were recovered from guava and banana fruits showed anthracnose symptoms collected from different orchards in Behera Governorate. Isolates were characterized according to types of colony colour, colony diameter, conidium shape and size, appressorium shape and size and the effect of different temperature degrees on isolates radial growth. The isolates showed mostly gray colony phenotype while the olive-gray and the dark-gray phenotypes were also existed in four out of the investigated eight isolates. Diameter of the developed colonies ranged between 80 and 85 mm. Conidia of the developed eight isolates were mostly monomorphic and exhibited cylindrical, hyaline conidia with size ranged between 14.5 and 19.1 μm for length and 4.4 and 6.5 μm for width. Clavate appressoria were recorded in all isolates. Irregular appressoria were also recorded accompanied with the clavate ones in five of the eight investigated isolates. The optimal temperature for radial growth was 25°C with rate of 8.0 - 8.37 cm, five days after inoculation. All isolates were pathogenic on different host species Guava cv. Balady, Apple cv. Golden Delicious, Banana cvs. Balady and Grantidin, Mango cv. Ewasy and Pepper cv. Balady. Apple fruits were the most susceptible for the infection by C. gloeosporioides isolates while pepper was the most tolerant for the infection. Moreover RAPD-PCR analysis using five random oligonucleotide primers revealed DNA fingerprints and considerable variations were revealed with primers tested. However, the RAPD-PCR phylogenetic analysis did not reveal known genetic entities for isolates from each guava and banana, since it did revealed two clusters for the highly virulent isolates and the moderately virulent isolates in the dendrogram of the tested C. gloeosporioides isolates. Anthracnose control of fruits by chitosan as a natural product was tested. The in vitro 2.5 % chitosan application significantly inhibited the growth of C. gloeosporioides isolates tested by 96.6 % on agar plates. The in vivo tests on fruits of different species, i.e. banana, mango, apple and guava confirmed the in vitro results. The chitosan treatment to artificially infected fruits reduced the development of symptoms, at the different chitosan concentrations, i.e. 1.5%, 2% and 2.5%. The 2.5% chitosan was the most affective concentration for anthracnose control in the different fruit species. The study supported the view that chitosan offers a safe alternative to synthetic fungicides in postharvest anthracnose diseases control and could be considered as a potential agrochemical of low environment impact.

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.

Genetic transformation with the gfp gene of Colletotrichum gloeosporioides isolates from coffee with blister spot

Genetic transformation with the gfp gene of Colletotrichum gloeosporioides isolates from coffee with blister spot

Pigments, total soluble phenols and lignin levels of coffee seedlings inoculated with Colletotrichum gloeosporioides

The objective of this work was to study the effects of different isolates of Colletotrichum gloeosporioides, as topigment level (chlorophyll a, b and total), total soluble phenols and soluble lignin in coffee seedlings obtained by artificially inoculatedtissue culture. The experiment was carried out in randomized block design in a 2 x 3 factorial scheme (2 genetic materials), 3 isolates(an isolate from mango fruits and another one from coffee plants), with 5 replicates and control (plants without inoculation). Theplants were inoculated with a suspension of 2 x 106 conidia.ml-1. The conidial suspension was sprayed on previously injured leaves.Leaves of inoculated plants were collected at 3 and 7 days after inoculation, except for leaves on the lower part of the plants.Afterwards, samples were prepared for the evaluation of chlorophyll, total soluble phenols and soluble lignin. The results showedthat the presence of the pathogen in healthy and diseased plants significantly reduced the amount of chlorophyll. At 7 days afterinoculation of healthy and diseased coffee plants higher total soluble phenol and soluble lignin levels were observed in response to theattack by Colletotrichum gloeosporioides.