Colletotrichum Musae Research Articles

Antifungal activities and active ingredients of Melodinus suaveolens Champ. ex Benth.

Four Melodinus species with antifungal activity were found in survey of the floral resources, in Shiwan Mountain Natural Reserve, Guangxi Province, China. Crude methanolic extracts of the twigs and leaves of Melodinus suaveolens exhibited potent antifungal activities against the plant pathogenic fungi Colletotrichum musae, Colletotrichum graminicola, Colletotrichum gloeosporioides and Alternaria musae, and the ethyl acetate fraction inhibited these pathogens at rates of 85.37, 91.47, 72.77 and 89.87%, respectively (5 mg/mL). A new compound, (2R, 3S, 5S, 6R)-1-O-methyl- chiro-inositol was isolated from the ethyl acetate fraction, along with 15 known compounds. The antifungal activities of compounds (1–16) were evaluated for the first time. Compound (4) had potent antifungal activity against C. gloeosporioides, C. graminicola and A. musae.

Thiophanate-Methyl Resistance and Fitness Components of Colletotrichum musae Isolates from Banana in Brazil.

Anthracnose, caused by Colletotrichum musae, is the most important postharvest disease of banana and is widely distributed among the banana production regions in Brazil. Although thiophanate-methyl is a fungicide frequently used in Brazilian banana orchards to control Sigatoka leaf spot, Collettotrichum populations are also exposed, resulting in the evolution of fungicide resistance and the inability to manage banana anthracnose. We investigated 139 Brazilian isolates of C. musae for thiophanate-methyl sensitivity in vitro. The 50% mycelial growth inhibition (EC50) values varied between 0.003 and 48.73 μg/ml. One-hundred and thirty isolates were classified as sensitive, with EC50 values ranging from 0.003 to 4.84 μg/ml, while the remaining nine isolates were considered moderately resistant, with EC50 values ranging between 10.43 and 48.73 μg/ml. Resistant or highly resistant isolates (EC50 > 100 μg/ml) were not found. A substitution of TAC for TTC at codon 200 in a coding region of the β-tubulin gene was associated with the moderately resistant phenotype. Applications of thiophanate-methyl formulation to detached banana fruit at the label rate (500 μg/ml) showed low efficacy in controlling the moderately resistant isolates on banana fruits. However, there is no indication of a reduction in fitness associated with fungicide resistance as sensitive and moderately resistant isolates do not differ with respect to mycelial growth rate (P = 0.098), spore production (P = 0.066), spore germination (P = 0.366), osmotic sensitivity (P = 0.051), and virulence (P = 0.057). Our results revealed absence of adaptability cost for the moderately resistant isolates, suggesting that they can be dominant in population if the fungicide continue to be applied.

Identification and antifungal activity analysis of two biocontrol antagonists to Colletotrichum musae

AbstractPostharvest anthracnose of banana caused by Colletotrichum musae is one of the major diseases resulting in huge economic losses worldwide. To control this disease using biocontrol agents, two antagonistic strains SD7 and NB20 with significant inhibitory effects on mycelial growth and conidial germination of C. musae were identified and evaluated in this study. The inhibitory effects of cell‐free culture filtrates of SD7 and NB20 on conidial germination of C. musae were both 100%, and those on mycelial growth of C. musae were 97.7 ± 0.9% and 95.0 ± 0.6%, respectively. The antifungal activities of cell‐free culture filtrates of both strains were still stable after they were stored at 4°C for 6 months. The control efficacies of cell‐free culture filtrates of SD7 and NB20 on postharvest anthracnose of banana were 55.9 ± 4.1% and 33.2 ± 3.9%, respectively. The disease severity (mean scale value) in banana fruit fingers was significantly lower after the treatment with a cultural suspension of the bacterial strain SD7 (1.4 ± 0.49) or actinomycete strain NB20 (2.0 ± 0.63), compared to that in the control (4.8 ± 0.40). After subculturing for 10 generations, the antifungal efficiency of NB20 remained stable, whereas that of strain SD7 declined obviously. Lastly, based on the morphological, physio‐biochemical and molecular characteristics, the bacterial strain SD7 was identified as Burkholderia cepacia, while the actinomycete strain NB20 was identified as Streptomyces katrae. The results from this study will provide the basis for developing an effective and novel biofungicide to control banana anthracnose disease.

Identification and Antifungal Activity of Metabolites from the Mangrove Fungus Phoma sp. L28

A new anthraquinone, 7-(γ,γ)-dimethylallyloxymacrosporin (1), along with five known analogues, macrosporin (2), 7-methoxymacrosporin (3), tetrahydroaltersolanol B (4), altersolanol L (5), and ampelanol (6), were isolated from the mangrove endophytic fungus Phoma sp. L28. All of them were first found in Phoma sp. Their structures were established by comprehensive spectroscopic analyses and comparison with the published data. These compounds displayed in vitro antifungal activities against Colletotrichum musae (Berk. & M. A. Curtis) Arx., Colletotrichum gloeosporioides (Penz) Sacc., Fusarium graminearum Schw., Penicillium italicum Wehme, Fusarium oxysporum Schlecht. f. sp. lycopersici (Sacc.) W.C. Snyder et H. N. Hansen, and Rhizoctonia solani Kuhn at different levels. Notably, compound 2 exhibited potent antifungal activity against Fusarium graminearum Schw. as compared with the positive control carbendazim.

Mycoflora associated with infected fruits of different varieties of Musa sapientum L. and their pathogenic potentiality

A total of 11 fungal species were isolated from the 25 infected fruit samples of three varieties (Sabri, Champa and Sagor) of Musa sapientum. The isolated fungi were Aspergillus flavus Link, A. fumigatus Fresenius, A. niger van Tiegh., Colletotrichum musae (Berk. & Curt.) Arx, Curvularia brachyspora Boedijn., Fusarium semitectum Berk. & Rav. Fusarium sp. Link, Penicillium sp., Pestalotiopsis disseminata (Thum) Steyaert, Rhizopus sp. Ehrenb. and Trichoderma viride Pers. ex Gray. Fusarium semitectum showed the highest (28.61) per cent association frequency in Sabri variety whereas Fusarium sp. showed the lowest (3.33). Curvularia brachyspora showed the highest (21.11) per cent frequency in Champa variety whereas A. fumigatus showed the lowest (2.78). Fusarium sp. showed the highest (41.67) per cent frequency in Sagor variety whereas T. viride showed the lowest (3.34). Among the isolated fungi C. musae, C. brachyspora, F. semitectum, Fusarium sp. and P. disseminata were found to be pathogenic to three banana varieties. The presence of Pestalotiopsis disseminata (Thum) Steyaert in Sabri variety of banana is the first record in Bangladesh.
 Dhaka Univ. J. Biol. Sci. 26(1): 101-110, 2017 (January)

Agronomic characterization and resistance of banana genotypes to Colletotrichum musae

Agronomic characterization and resistance of banana genotypes to Colletotrichum musae

Antagonistic Yeasts for Biocontrol of the Banana Postharvest Anthracnose Pathogen Colletotrichum musae

AbstractThe biocontrol potentials of Candida tropicalis YZ1, C. tropicalis YZ27 and Saccharomyces cerevisiae YZ7 against the postharvest anthracnose pathogen Colletotrichum musae were investigated. Treatments with all the three biocontrol agents (1 × 108 CFU/ml) significantly reduced the natural anthracnose disease severity of harvested banana fruits stored at ambient condition. Germination and survival of C. musae spores were markedly inhibited by all the three yeast strains in in vitro tests. The niche overlap index (NOI) was used to determine the interaction between the antagonists and C. musae, and the results (high NOI values) suggest competitive exclusion of C. musae by the yeast strains. C. tropicalis YZ27 inoculated on banana wounds exhibited rapid colonization and maintenance of its population on the inoculated site. The biocontrol efficacy was also observed as a function of concentration of the antagonist applied. The fruits treated with C. tropicalis YZ27, 36 h before pathogen inoculation, showed the best results with 96.0% disease inhibition followed by those treated 24 h before with 84.0% inhibition. The above results point to competition for nutrients and space as the main mechanism of antagonistic action of C. tropicalis YZ27 against C. musae.

Efficacy ofCandida oleophila,strain O, in preventing postharvest diseases of fruits

The biocontrol potential of the yeast Candida oleophila, strain O, against Penicillium expansum and Botrytis cinerea in stored apples, Penicillium spp. in stored citrus fruit and Colletotrichum musae in stored bananas was investigated in 9 semi-commercial trials using chemical fungicides as references. NEXY®, a formulate based on C. oleophila, strain O, in combination with its nutritional additive calcium gluconate, was applied at 233 g 100 L-1 by drenching or dipping wounded fruits. Fruits were then inoculated with the studied pathogens and placed in cold storage conditions (1-6°C for apples and citrus fruit, and 13°C for bananas). In 7 of 9 semi-commercial trials, high protective levels were observed with the application of NEXY® (62 to 98% of efficacy in term of disease incidence reduction). These protective levels were very similar to those of used reference (imazalil or thiabendazole) (66 to 99%). In one of these 9 trials, disease incidence reduction reached 43% for NEXY® and only 30% for thiabendazole. Only in one trial, NEXY® did not control the growth of studied pathogen and, in the same time, thiabendazole gave only 28% of protection. These results support that C. oleophila, strain O., has a broad spectrum of activity against some important postharvest pathogens on a variety of fruits. NEXY® is a good alternative to synthetic fungicides in particular in low and moderate disease pressure conditions.

Isolation, screening and in vitro evaluation of bacterial antago-nists from spent mushroom substrate against Colletotrichum musae

Colletotrichum musae is a major pathogen in banana fruit which causes heavy losses at the postharvest stage. As a viable alternative to harmful chemical usage and physical control measures, the potential of using bacterial antagonist against C. musae was evaluated in this study. Out of a total of 92 bacterial isolates derived from dilution plates of aqueous extracts of spent mushroom substrate (SMS), 43 isolates were initially selected for screening for antagonistic activity against the C. musae isolate CMK01. Screening of the selected bacterial isolates revealed that 39 of the tested isolates significantly inhibited fungal growth in vitro compared to the control (P <0.05). The diffusible substances secreted by the five selected isolates showed 100% inhibition of colony growth, while (13-58%) inhibition was observed with volatile compounds. Light microscopic observations revealed deformation and blackening of C. musae hyphal tips in the colony margins facing the antagonists. Four of the selected five bacterial isolates were identified with 100% precision as Pseudomonas aeruginosa based on partial 16S rDNA sequences. These promising antagonists have the potential to be developed as effective biocontrol agents against C. musae.

Optimisation of medium and culture conditions for the production of antifungal substances to Colletotrichum musae by Trametes elegans SR06

ABSTRACTAn endophytic fungus SR06 was isolated from a leaf of Amomum villosum Lour., which had a high antagonistic effect on Colletotrichum musae with an inhibition ratio of 41.20%. The antifungal substances could be secreted into fermentation broth, which had a high inhibitory activity. Strain SR06 was identified as Trametes elegans according to internal transcribed spacer sequence analysis. Response surface methodology (RSM) was used to optimise the process parameters of antifungal substances production. Using the Plackett–Burman design, three variables (glucose, yeast extract and MgSO4·7H2O) exerted significant effects on antifungal substances production. Then RSM experiments were conducted to further optimise the three variables. The optimal medium components were 26.45 g/L glucose, 10 g/L peptone, 14.96 g/L yeast extract and 1.49 g/L MgSO4·7H2O, and the optimal initial pH was 6.0, with a culture temperature of 28°C and a shaking speed of 180 rpm. Under the optimised conditions, a significant improvement in the production of antifungal substances by T. elegans SR06 was accomplished, and the inhibition zone diameter was up to 29.2 mm after culturing for 7d. The average control efficacy of the fermentation supernatant of SR06 against C. musae was 51.29% on banana fruits, which was significantly higher than that of the fungicide carbendazim.

Activity of chitosan films enriched with the essential oil of Alpinia malaccensis rhizome against S. aureus, E. coli and C. Musae

In this paper, the in vitro antimicrobial activity of Alpinia malaccensis rhizome oil was investigated in its pure form and incorporated into chitosan films, against Colletotrichum musae, Staphylococcus aureus and Escherichia coli. Dry rhizome oil of A. malaccensis was extracted using steam distillation. Chitosan films enriched with the oil were prepared by casting as a potential bio-based food packaging film. The major constituent of A. malaccensis oil was identified as 1,8-cineole by GC-MS. The antifungal activity of the essential oil (EO) was tested using the disk diffusion method. The minimum inhibitory concentration (MIC) and the minimum lethal concentration (MLC) for C. musae was 100.0 and 300.0 μg μL-1, respectively. A liquid bioassay method was used to determine the antifungal efficacy of the oil enriched chitosan films against C. musae. More than 50 % inhibition of the growth of the fungus was achieved when the oil concentrations in EO-chitosan films was between 0.08 – 0.40 μg mm-2. The antibacterial activity of the oil and the oil enriched films was determined by measuring the optical density of the cultures at 610 nm. The optical density (OD610) values of S. aureus and E. coli cultures showed a sharp and gradual reduction, respectively with increasing oil concentration. The growth of S. aureus was negligible at oil concentrations higher than 5.0 μg μL-1. The oil enriched films showed a lower inhibition of the growth of both bacteria.

Etiological agents of crown rot of organic bananas in Dominican Republic

Crown rot is a postharvest disease with a great negative impact on banana fruit quality. The infections occur at harvest, but the symptoms appear after overseas transportation. Different fungal pathogens are involved in crown rot, varying according to farming area. In this study we focused on etiology of organic banana crown rot in the Dominican Republic, which is one of the leading exporters of organic bananas. Bananas from five organic farms and their corresponding packing stations located in the Valverde province were studied. Over a period of three years, 558 banana hands were collected and a total of 5000 fungal colonies were obtained from the crown tissues and 518 representative colonies were purified, characterized and identified using morphological and molecular methods. Fungi were found in all samples from field and from packing house and were distributed in 11 genera. The fungal community was dominated by Fusarium, the most frequent genus (55%) found in more than 80% of all samples. The genus was represented by nine species; Fusarium incarnatum 53%, the most frequent, followed by Fusarium verticillioides 12%, Fusarium sacchari 12%, Fusarium proliferatum 7%, and Fusarium solani 6%. The five least frequent species were Colletotrichum musae, 7% overall frequency and found in 13% of all samples; Lasiodiplodia theobromae and Lasiodiplodia pseudotheobromae, 4% and 1% overall frequency, respectively, both species found in 7% of all samples; Nigrospora sp. 11% overall frequency, Alternaria spp. 6% overall frequency, followed by Phoma spp., Pestalotiopsis sp., Curvularia spp., Microdochium sp. and some other species, known to be saprophytes, with frequency lower than 2%. The etiological agents of crown rot disease can be ranked based on their presence and pathogenicity as follows: Fusarium incarnatum, Colletotrichum musae, Fusarium verticillioides, Fusarium sacchari, and Lasiodiplodia theobromae.

Antifungal Activity of Croton aromaticus L. in vitro, Against Post-Harvest Fungal Pathogens Isolated from Tropical Fruits

Synthetic fungicides are widely used in controlling postharvest diseases of fruits worldwide. The interest of finding natural bioactive components has increased due to the harmful effects of synthetic fungicides on environment and health. Present study was an attempt to evaluate the antifungal activity of ethanolic extract of Croton aromaticus leaves in vitro, against mycelial growth and spore germination of postharvest fungal pathogens isolated from banana ( Colletotrichum musae , Lasiodiplodia theobromae ), papaya ( Colletotrichum gleosporioides , L. theobromae ) and mango ( Alternaria alternata , Pestalotiopsis mangiferae , L. theobromae ), and to analyze phytochemicals of the extract qualitatively. Inhibitory effect of the ethanolic extract was investigated by well diffusion method with different concentrations (1, 5, 10, 30, 50, 100, 200 and 300 mg ml -1 ) along with positive control (Captan) and negative control (DMSO). Significant inhibitory effects (P C. musae , P. mangiferae , A. alternata and C. gleosporioides except L. theobromae . The lowest minimum inhibitory concentration (MIC) value of the leaf extract (5 mg ml -1 ) was observed for C. gleosporioides and P. mangiferae . Qualitative phytochemical analysis revealed the presence of alkaloids, terpenoids, quinones, phytosterols and flavonoids in leaf extract of the plant. Thin layer chromatographic (TLC) assay revealed the presence of four bioactive compounds with Rf values of 0.551, 0.672, 0.810 and 0.913.

Antifungal activity of plant extracts against Colletotrichum musae, the post harvest anthracnose pathogen of banana cv. Martaman

Purpose – The purpose of this paper was to determine the antifungal activities of different solvent extracts of common plants in vitro and in vivo against banana anthracnose fungus Colletotrichum musae (Berk &amp; M.A. Curtis) Arx, and to investigate its effects on the pathogen and identify the bio active component(s). Design/methodology/approach – Extracts were obtained from leaves, tender shoots, rhizomes, bulbs, seeds and fruits of 42 naturally growing plant species following hot sequential extraction. Preliminary screening of the solvent extracts was done based on the inhibition of radial mycelial growth of C. musae following poison food technique and conidial germination inhibition by cavity slide technique. The selected extracts were assessed for their effect on harvested banana in reducing anthracnose during storage. The active components in the bio-active fractions of plant extract were identified by gas chromatography-mass spectroscopy. Findings – Methanol extracted a larger quantity of material (between 6.9 and 12.5 per cent) than hexane or chloroform, and all its extracts were active against the test pathogen with mycelial growth inhibition ranging from 13.70 to 88.89 per cent. Zingiber officinale rhizome extract as well as Polyalthia longifolia and Clerodendrum inerme leaf extracts exhibited more than 80 per cent inhibition of mycelial growth. Total inhibition of spore germination of C. musae was recorded in Z. officinale and P. longifolia extracts at 0.3 per cent w/v and 0.5 per cent w/v concentration, respectively, while only 68 per cent spore inhibition was recorded in C. inerme at 0.5 per cent w/v concentration. Of the three plant species, Z. officinale had the best antifungal activity (18.0 per cent disease incidence; 2.2 disease severity scale) when banana fruits were dipped in the extract at a concentration of 0.5 per cent w/v at 5 days of storage in ambient condition (80-82 per cent R.H., 27 ± 1°C). The bio-active compounds in the extract of Z. officinale were identified as alpha-curcumene and zingerone. Originality/value – Based on the antifungal activity, plant extract of Z. officinale can be used as an effective alternative to chemicals in controlling anthracnose pathogen in harvested banana.

A New Antifungal Isocoumarin from The Endophytic Fungus Trichoderma Sp. 09 of Myoporum bontioides A. Gray.

Background:Myoporum bontioides A. Gray is a commonly used medicinal plant in China. Recently, the chemical and bioactive investigations to the endophytic fungi of this plant have led to several new compounds with antimicrobial and cytotoxic activities. To find out more active molecules, the metabolites of an endophytic fungus, Trichoderma sp. 09 from the root of Myoporum bontioides were investigated.Materials and Methods:The metabolites were isolated by column chromatography on silica gel, and their structures were elucidated on the basis of spectroscopic analysis[one-dimensional (1D), two-dimensional (2D)-nuclear magnetic resonance (NMR), Mass spectrometry (MS)], and by comparison with the published data. The dilution method was used for the evaluation of antifungal activity.Results:Four metabolites were isolated and identified as: dichlorodiaportinolide (1), dichlorodiaportin (2), diaportinol (3), and diaportin (4). Compounds 1 and 2 showed weak to high antifungal activities against Colletotrichum musae (Berk. and M. A. Curtis) Arx and Rhizoctonia solani Kühn, as compared with the positive control.Conclusions:Compound 1 was a new isocoumarin being worthy of consideration for the development and research of antifungal agents.SUMMARY A new isocoumarin named dichlorodiaportinolide, along with dichlorodiaportin, diaportinol, and diaportin were isolated from the endophytic fungus Trichoderma sp. 09 of the root of Myoporum bontioides.Dichlorodiaportinolide and dichlorodiaportin showed weak to high antifungal activities against musae and R. solani (MIC values from 6.25 to 150 μg/mL).Dichlorodiaportinolide and dichlorodiaportin were inactive to P. italic and F. graminearum (MIC values > 200 μg/mL). Abbreviations used: IR: Infrared Radiation, HR-ESI-MS: High resolution electrospray ionization mass spectroscopy, LCMS-IT-TOF: Liquid chromatography mass spectroscopy-Ion trap-Time-of-flight, UV: Ultraviolet-visible, HMBC: Heteronuclear multiple bond correlation, NOE: Nuclear Overhauser effect.

Directed assembly of cobalt(II) 1-H-indazole-3-carboxylic acid coordination networks by bipyridine and its derivatives: structural versatility, electrochemical properties, and antifungal activity

This paper describes the hydrothermal synthesis, full characterization, and architectural diversity of three intriguingly bioactive cobalt–organic frameworks, namely, 3D [Co(HL − )2(BPY)] n ·4nH2O (1), 2D [Co(HL − )2(BPE)] n (2), and 2D [Co(HL − )2(DPP)] n (3) coordination polymers, synthesized through a mixed ligand strategy using H 2 L (1-H-indazole-3-carboxylic acid) as a main structural block and the flexible bipyridine and its derivatives (BPY = 4,4′-bipydine, BPE = 1,2-bis(4-pyridyl)ethane, DPP = 1,3-bis(4-pyridyl)propane) as auxiliary ligand sources. Complexes 1–3 were isolated as air stable and slightly soluble crystalline solids and characterized using elemental analysis, FT-IR, electrochemical technique, thermogravimetric analysis, powder X-ray diffractometer, and single-crystal X-ray crystallography. The bipyridine derivatives played key roles in defining the structural space group and dimensionality feature of the obtained networks. The abundant H-bonding and π–π stacking interactions in complexes 1–3 gave rise to their intricate metal–organic structures of 3D (1), 2D (2), and 2D (3). In addition, the solutions of complexes 1–3 showed profound antifungal activities against the selected strain of Colletotrichum musae compared with the controlled group using benomyl as a traditional agrochemical fungicide.

Identification of a set of up-regulated genes due to infection by Colletotrichum musae in a dessert banana cultivar, moderately- resistant to anthracnose

Understanding the mechanisms of host plant resistance at molecular level is useful towards designing effective disease management programmes against infections of plant pathogens. The present study was conducted to identify host plant genes expressed in response to infection by Colletotrichum musae using a moderately-resistant cultivar of banana (Seenikesel) to anthracnose. The expression profile of a selected defense-related gene over the infection process in the banana cultivar Seenikesel was also determined. Identification of genes was done by differential hybridization of a cDNA library constructed from peel tissues of banana inoculated with C. musae. Up-regulated genes due to C. musae infection were predicted through DNA homology search. Among the identified putative defense related genes, expression profile of Germin-like protein was studied by relative RTPCR over a period of 144 h after inoculation. The set of up-regulated gene transcripts identified in the present study were responsible for plant defense, stress response, growth, development, protein synthesis, protein folding and stabilization. Expression of Germin-like protein gene homologue was comparatively high at the late phase of inoculation (96 h after inoculation) of C. musae in banana cultivar Seenikesel. Tropical Agricultural Research Vol. 25 (2): 240 – 251 (2014)

Some Preliminary Studies of Colletotrichum musae Associated with Banana Anthracnose Disease in Jaffna District, Sri Lanka

Anthracnose caused by Colletotrichum species is a common postharvest disease of banana fruit in Sri Lanka. The present study was conducted to determine morphological and pathogenic variations and influence of culture media on the growth of Colletotrichum musae isolates, causing anthracnose disease of banana. Six colletotrichum musae isolates were isolated from 3 different banana local cultivars ('Kathali', 'Kappal', 'Etharai'). Length, width and length: width ratio of the spores differed significantly among 6 isolates of C.musae. Among the different media tested, Potato and Carrot dextrose agar media supported significantly the maximum growth of all the six isolates of C. musae. Recommended dosage of the fungicides Homai (Thiophanate-methyl 50% + Thiram 30% WP) and Topsin (Thiophanate-methyl 50%) completely inhibited the mycelia growth of six isolates in vitro. Characteristic symptoms of anthracnose were started to develop by all the isolates of C. musae on banana variety 'kathali' 2 days after inoculation of the pathogen. The present study revealed that morphological and pathogenic variations exist among different isolates of C. musae infecting banana fruits in Jaffna district of Sri Lanka.

Analysis of differentially expressed gene profiles in a resistant banana cultivar after infection by Colletotrichum musae

The expression profiles of genes in banana cultivar (Seenikesel) due to infection of Colletotrichum musae was analysed and functions of differentially-regulated expressed sequence tags (ESTs) were deduced. Among the up-regulated ESTs, 51%, 16% and 11% were related to defence response-, stress response- and energy and metabolism-related genes, respectively. Moreover, 22% and 11% of the down-regulated genes, respectively accounted for defence and stress response-related functions and 11% for protein synthesis, folding and stabilization. In addition, similarly-regulated gene transcripts were identified and 30%, 30% and 20% of them were respectively related to defence, energy and metabolism and protein synthesis folding and stabilization functions. Relative expression of three up-regulated gene transcripts, namely gamma glutamyl transferase (GGT), germin-like protein (GLP) and β-1,3-glucanase on peel tissues over a period after inoculation of C. musae was analysed. Relative fold increase of expression of the three genes showed a positive correlation with anthracnose lesion development and ripening. This study elucidated the genetic background of resistance of cultivar Seenikesel, possible mechanisms of resistance and correlated the expression of selected gene transcripts towards C. musae infection and fruit ripening.

Identificación genética de aislamientos de Colletotrichum spp. causantes de antracnosis en frutos de aguacate, banano, mango y tomate de árbol

Anthracnose is a major disease affecting the production of tropical fruit trees on a global level. Our objective was to identify at the species level Colletotrichum isolates causing anthracnose in fruits of avocado, banana, mango, and tamarillo by multilocus phylogenetic analysis based on sequencing data from the ITS region and from the βtubulin-2 and glyceraldehyde-3-phosphate dehydrogenase genes. We evaluated the morphology of colonies, conidia, and appressoria for each species. We obtained 16 isolates from fruits exhibiting symptoms of anthracnose, which were confirmed using the wound and drip inoculation method as causing anthracnose in fruits of their respective hosts. The isolates were identified as Colletotrichum asianum, Colletotrichum fructicola, or Colletotrichum musae within the Colletotrichum gloeosporioides species complex, or as Colletotrichum tamarilloi within the Colletotrichum acutatum species complex. This study contributes to the knowledge of species causing anthracnose in tropical fruits in Colombia, which will facilitate the design of diagnosis techniques and the selection of better disease management strategies. © Acad. Colomb. Cienc. Ex. Fis. Nat. 2015.