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Application of plant derivatives, including Jatropha curcas seed oil, is among the newest alternative methods for controlling Fusarium oxysporum f. sp. gladioli , one of the most widespread and destructive gladiolus fungi. Phorbol esters are considered the main toxic compounds in J. curcas seeds; therefore, knowing the amount of these compounds for the possible application of the oil as fungicide is of utmost importance, including the identification and evaluation of the fungicidal effect of its compounds. In this study, phorbol ester content in the seed oil of a native J. curcas species from the state of Chiapas, Mexico, was almost negligible (0.15 mg g −1 ). The result of the fractionation indicates that triacylglycerides were the dominant lipids. Further methanolysis of J. curcas seed oil and its fractions gave 49% oleic acid. Antifungal assays showed that the seed oil of J. curcas at 2.5 mg mL −1 inhibited the growth rate of F. oxysporum f. sp. gladioli to about 0.77 cm day −1 , while the effect of the G1–G9 fractions, obtained by column chromatography, tested on this parameter was variable. The best inhibitory concentration for G3–G9 fractions was 200 mg L −1 . In G4 fraction at a similar concentration, the lowest percentage germination (about 57%) was observed. From the active compounds and commercial triacylglycerides tested, no pattern was associated with concentration-inhibition in the growth rate assay, while the lowest percentage germination was with the commercial triolein at 500 mg L −1 (30% approximately).

Las ventajas de México como productor florícola recaen en su diversidad de climas y su cercanía al mercado norteamericano. Actualmente la exportación de flores y plantas ha quedado consolidada, tal como es el caso del gladiolo al estar libre de arancel. Los principales estados productores son Puebla, Estado de México y Morelos. La producción comercial de la flor de corte de gladiolo se inicia a través de la plantación del cormo; el cual es afectado por diversos patógenos que ocasionan su pudrición, como los del género Penicillium que ataca durante el almacenamiento, provocando desarrollo limitado de raíces y aborto floral. Éste provoca infecciones a través de heridas y sitios de ruptura; se encuentra presente en un 90% de material vegetal aparentemente sano. Los objetivos de este trabajo fueron aislar e identificar cultural, morfológica y molecularmente, así como realizar pruebas de patogenicidad para determinar las especies de Penicillium causantes de la pudrición. A partir de cormos variedad GrandPrix® (10/12) con diferentes niveles de deterioro morfológico y de acuerdo a una escala hedónica visual de siete puntos. Se aisló e identificó a P. verrucosum Dierckx y P. rugulosum Thom como causantes de la pudrición de cormos, este último reportado por primera vez como fitopatógeno en gladiolo.

Se desarrollaron modelos matemáticos del crecimiento y germinación in vitro de Alternaria alternata en presencia de aceites esenciales. Mediante el análisis de componentes principales, se encontraron similitudes entre ellos considerando su composición volátil. El crecimiento micelial y germinación de conidios de A. alternata se evaluó en PDA con aceites de canela, epazote y limón (0.25, 0.5, 1.0 µL mL-1). Los aceites se obtuvieron por hidrodestilación y comercialmente. Se caracterizaron por cromatografía de gases acoplada a espectrometría de masas. Para ajustar los datos experimentales y predecir su comportamiento se emplearon las ecuaciones de Baranyi y Roberts y logística. Por su composición química los aceites se agruparon en: 1) canela (comercial y no-comercial), en el que predominó el cis-Cinamaldehído, 2) limón comercial (D-Limoneno), y epazote (comercial y no-comercial), con Ascaridol y ρ-Cimeno y 3) limón no-comercial. El aceite de canela (0.5 y 1.0 µL∙ mL-1) inhibió el crecimiento micelial de A. alternata, mientras que, la germinación se inhibió 100 % con la presencia de aceites de limón y epazote (0.25 y 0.5 µL∙ mL-1). Los modelos matemáticos y el análisis de componente principales, son herramientas eficaces para entender el efecto de los aceites esenciales en A. alternata.

"Se desarrollaron modelos matemáti - cos del crecimiento y germinación in vitro de Alter - naria alternata en presencia de aceites esenciales. Mediante el análisis de componentes principales, se encontraron similitudes entre ellos consideran - do su composición volátil. El crecimiento micelial y germinación de conidios de A. alternata se eva- luó en PDA con aceites de canela, epazote y limón (0.25, 0.5, 1.0 μL mL -1 ). Los aceites se obtuvieron por hidrodestilación y comercialmente. Se carac - terizaron por cromatografía de gases acoplada a espectrometría de masas. Para ajustar los datos experimentales y predecir su comportamiento se emplearon las ecuaciones de Baranyi y Roberts y logística. Por su composición química los aceites se agruparon en: 1) canela (comercial y no-comer - cial), en el que predominó el cis-Cinamaldehído, 2) limón comercial (D-Limoneno), y epazote (comer - cial y no-comercial), con Ascaridol y ρ-Cimeno y 3) limón no-comercial. El aceite de canela (0.5 y 1.0 μL∙ mL -1 ) inhibió el crecimiento micelial de A. alternata , mientras que, la germinación se inhibió 100 % con la presencia de aceites de limón y epa- zote (0.25 y 0.5 μL∙ mL -1 ). Los modelos matemá - ticos y el análisis de componente principales, son herramientas eficaces para entender el efecto de los aceites esenciales en A. alternata ."

The State of Morelos is the third biggest gladiolus producer in Mexico. However, this ornamental is affected by the disease named corm rot or fusarium yellows, characterized by leaf yellowing, epinasty and wilting, and caused by fungi of the genus Fusarium. The first objective was to corroborate the pathogenicity of the 45 isolates obtained. The second objective was to identify and characterize morphologically and molecularly by polymerase chain reaction-internal transcribed spacer (PCR-ITS), the highly pathogenic isolates and comparatively analyze the fungal species involved with the reference strain Fusarium oxysporum f. sp. gladioli (Fog). The third objective was to quantify the phorbol esters in Jatropha curcas oil and evaluate their antifungal potential on mycelial growth and conidial germination of different Fusarium species. Eleven isolates were highly significant pathogenic (P < 0.001). Three fungal species were identified in basal stems and damaged corms taken from field plants, namely F. oxysporum, Fusarium solani and Fusarium proliferatum. Molecular analyzes corroborated the species identified and their sequences were deposited in the National Center for Biotechnology Information (NCBI) gene bank. The percentage of oil obtained was 61.5 %; the phorbol ester content in the oil was 1.52 mg g-1 of 12,13-phorbol myristate. All species identified and the reference strain was sensitive to the 5 mg mL-1 oil concentration. Key words: Corm rot, Fusarium, molecular analysis, phorbol esters, Fusarium development.

Summary Environmental and technological influences complicate the task of achieving disease-free products in the ornamental industry. Research is needed to support progress in the development of integrated environmental, biological, and chemical control techniques for management of diseases in floriculture. However, due to the unavailability of desirable resistance in cultivars and exorbitant cost of chemicals for the management of diseases in ornamentals, the introduction of biological and alternatives methods is believed to be an alternative to chemical methods. Moreover, management practices using a single control measure are not successful in controlling the diseases. For this reason, integrated management practices based on resistant cultivars, chemical methods, biological methods, and alternatives under experimentation (chitosan, extracts, and essential oils) are being adopted for successful management of diseases in ornamentals.

Summary A number of studies have confirmed the in vitro fungicidal effect of chitosan on various phytopathogenic fungal families including among others, Mucoraceae, Pleosporaceae, and Glomerellaceae. Investigations of the morphology and ultrastructure of the chitosan-treated fungi in in vitro studies and during the plant-pathogen interaction of various pathosystems have been carried out by using conventional optical/light microscopy and with other advanced instruments including SEM, TEM, and confocal microscopy. The electrostatic interaction between chitosan and the microorganism is noted by dramatic alterations observed from the damaged structure of the cell wall and plasma membrane. The integrity of organelles including vacuoles was seriously affected, leading in some cases to lysis of the fungal cell. During the host-pathogen interaction, formation of structural barriers by the host, mainly through inter- and intracellular synthesis of phenolic-lignin-like material that stops fungal invasion, was also observed. Fungal growth was not beyond the outer cortical area of the infected tissues, while damage on fungi was similar to those observed in in vitro studies. Microscopic examinations have confirmed the fungicidal and eliciting properties of chitosan.

"El higo adquiere más importancia económica debido al contenido nutricional y propiedades funcionales. Se evaluó el efecto de la aplicación de recubrimientos de quitosano 1% + cera de abeja 0.5% y de quitosano + cera de abeja + aceites esenciales de canela 0.025% o + limón 1%, sobre la calidad postcosecha de higos cv. ‘Black Mission’ durante 16 días de almacenamiento a 5ºC. En general, al término de este periodo, en comparación con la fruta no tratada, ninguna de las cubiertas redujo la pérdida de peso, la producción de CO2 fue casi similar en todos los tratamientos en un rango de 69.4 a 86.9 ml CO2 kg-1 h-1, la firmeza de los tratados con quitosano + cera de abeja, fue dentro de un valor comercial aceptable de aproximado 16N. Los SST fueron ligeramente mayores (16%) en los frutos con las cubiertas con los aceites esenciales. La actividad antioxidante fue mayor en los tratados con aceite esencial de limón (68%). Se observó un desarrollo normal del color (verde a morado). La presencia de bacterias mesófilas aerobias fue menor con el quitosano + cera de abeja (UFC = 5.0), mientras que la cuenta de hongos/levaduras fue menor con las cubiertas de quitosano + cera de abeja + aceite esencial de canela o aceite de limón (UFC = 4.3 y 0, respectivamente). El mayor control (50%) de los hongos fitopatógenos fue también con la cubierta que contenía el aceite esencial de limón. Los principales hongos aislados pertenecían a los géneros Alternaria, Aspergillus y Penicillium."

During storage of tomatoes, Rhizopus stolonifer rapidly spreads towards adjacent fruits causing severe economic losses while Escherichia coli may cause serious even life threatening diseases. Chitosan-based materials can be used as edible films or coatings to avoid water loss and microbial spoilage. Waxes and essential oils may also be considered for use as antimicrobial agents in chitosan coating. In this study, various chitosan-based formulations (1%) mixed with beeswax (0.1%), oleic acid (1.0%), and lime or thyme essential oil (0.1%) were tested on tomato at three different maturity stages to control R. stolonifer and E. coli DH5α at storage temperatures of 12 °C and 25 °C. Control fruit were only dipped in water. Overall, fruit were wounded, coated and inoculated. Once the coatings were applied, 20 μl of R. stolonifer spore suspension at 10 5 spores ml −1 concentration and 35 μl of bacterial solution of E. coli DH5α, at 10 5 cfu μl −1 , concentration, were dispensed over the wounded surface. Experiments were carried out in vitro , at a small scale and at semi commercial level. Overall, the protection effect of coating applications was better against E. coli DH5α than R. stolonifer . For in vitro experiments the best coatings was that of chitosan (1%) + beeswax (0.1%) + lime essential oil (0.1%) since no growth of R. stolonifer and E. coli DH5α took place. Other coating that stopped R. stolonifer growth was that of chitosan (1%) + oleic acid (1%) + lime essential oil (0.1%) while for E. coli DH5α were chitosan (1%) + beeswax (0.1%) + thyme essential oil (1%) and chitosan (1%) + beeswax (0.1%). Observation with an electronic scanning microscope showed distorted mycelia and no development of R. stolonifer sporangiospores, and no growth of E. coli DH5α when both microorganisms were grown on the formulation of chitosan (1%) + beeswax (0.1%) + lime essential oil (0.1%). For E. coli DH5α, this same formulation applied on tomatoes at a small scale and in the semi commercial level completely controlled E. coli DH5α at both storage temperatures. The application of chitosan-based edible coating containing beeswax and lime essential oil is promising to follow since it is an environmentally-friendly alternative to control this important pathogenic microorganism. Export tomato producers might benefit from this nonchemical alternative.

A. T. Rodriguez-Pedroso1; M. A. Ramirez-Arrebato1; D. Rivero-Gonzalez1; E. Bosquez-Molina2; L. L. Barrera-Necha3; S. Bautista-Banos3¶ 1Instituto Nacional de Ciencias Agricolas (INCA), km 3.5 Carr. Tapaste-San Jose de las Lajas, Gaveta Postal Num. 1, La Habana, Cuba. C. P. 32700. CUBA. 2Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186 Michoacan y la Purisima, Col. Vicentina, D. F. Mexico. C. P. 09340. MEXICO. 3Centro de Desarrollo de Productos Bioticos, Instituto Politecnico Nacional, km 8.5 Carr. Yautepec-Jojutla, San Isidro, Yautepec, Morelos, Mexico C. P. 62731. MEXICO. Correo-e: sbautis@ipn.mx; atania@inca.edu.cu (¶Autora responsable)

Se prohíbe la reproducción total o parcial de este libro así como su tratamiento o distribución informática de alguna forma o por cualquier medio, ya sea electrónico, magnético, mecánico, fotocopia, registro u otros métodos, sin el permiso previo y por escrito del Departamento de Química de la Facultad de Ciencias de la Universidad de Los Andes, Mérida, Venezuela. 297-309

The fungistatic or fungicidal effect of powders, and aqueous and ethanolic extracts of seeds, and monthly harvested leaves of huamuchil (Pithecellobium dulce ) were evaluated for fungicidal activity, against Botrytis cinerea , Penicillium digitatum , and Rhizopus stolonifer . Fungicidal activity of huamuchil powders and aqueous extracts were also evaluated on strawberry fruit during storage. Preliminary characterization of the active compound responsible for the fungicidal effect was carried out using thin layer chromatography and spectrophotometry. Results indicated that powders had the best fungicidal effect, in both in vitro and in situ studies. Fungistatic or fungicidal properties were associated with the plant organ and harvest month. A correlation between high absorbance values of extracts with the fungicidal or fungistatic effect was not observed. The highest fungistatic or fungicidal effect for both in vitro and in situ studies was recorded from extracts of leaves harvested in months having more stressful environmental conditions; the cold season (October/February) and, the dry, hot season (April and June). Attempts to characterize the active compound suggest that kaempferol may be responsible for the fungicidal effect. # 2003 Elsevier Science B.V. All rights reserved.

L. hintonii C. P. Smith grows in the Central Highland forests of Mexico at altitudes between 2800 m to 3200 m above see level. Members of the genus Lupinus produce quinolizidine alkaloids as main chemical defensive compounds against herbivores. Surprisingly alkaloid profiles are rather constant within this species, while substantial variation was found when compared to morphologically closely related other taxa. As part of a phytochemical project on Mexican wild lupins, we report on the alkaloid profiles of seeds and leaves of L. hintonii. 19 alkaloids could be identified by capillary GLC-MS. Six major alkaloids occurred in leaves and seeds: 13-hydroxylupanine (28% and 45% respectively), tetrahydrorhombifoline (31% and 23% respectively), angustifoline (2% and 4% respectively), lupanine (7% and 5% respectively), 13α-tigloyloxylupanine (19% and 5% respectively) and 4α-angeloyl-3β-hydroxylupanine (9% and 2%). This chemical pattern resembles that of the North American lupin L. floribundus

Sapote mamey is an important tropical fruit of Mexico. However during the harvest season high incidence of postharvest fungi are present. Isolations of infected fruit in 1998 and 1999 indicated Pestalotia and Botryodiplodia as the main postharvest fungi. Percentage infection significantly varied according to harvest date for both 1998 and 1999. In 1988 percentage infection decreased from 65% to 20% as fruit ripening increased while in 1999 fruit infection varied from 100% to 10%. Infection caused by Botryodiplodia was more frequent.

Rhizopus stolonifer is considered the most important species in the genus Rhizopus . Disease symptoms that characterize R. stolonifer infection are watery areas quickly covered by coarse, gray hairy mycelia forming a mass of black sporangia at their tips. Infection usually occurs during harvest and handling. Due to the wide array of hosts that R. stolonifer can infect and its fast penetration and colonization, it has become an important target to control. Overall, R. stolonifer is controlled using synthetic fungicides; among the various registered fungicides are thiabendazole, benomyl, imazalil, propiconazole and thiocarbamates. The fungicides fluodioxonyl, tebuconazole, fenhexamide and azoxystrobin have also achieved notable control of this fungus. Sanitizers like chlorine, sodium hypochlorite, calcium hypochlorite, ozone and peracetic acid have shown to have good control on Rhizopus . Of the various non-conventional methods under experimentation, antagonists have attracted considerable attention. Bacteria including Pantoe agglomerans , Enterobacter cloacae , Pseudomonas syringae , and Bacillus spp., as well as yeasts of the genera Pichia , Kloeckera , Candida , Cryptoccoccus , Metschnikowia and Acremonium , have exerted a significant control on this fungus. Aqueous plant extracts belonging to the botanical families Amaryllidaceae, Annonaceae, Arecaceae, Bromeliaceae, Caricaceae, Lamiaceae, Lauraceae, Leguminosae, Meliacea, Myrtaceae, Pinaceae, Sapotaceae, Solanaceae and Urticaceae, along with the essential oils of the genera Thymus , Cinnamom , Origanum and Citrus , have also produced excellent results under experimentation. UVC irradiation levels of up to 3.6 kJm 2 showed levels of control up to 50% on R. stolonifer . Chitosan, a widely known chitin derivative, alone or in combination with other natural products, has been able to reduce significantly Rhizopus soft rot on various horticultural commodities at various concentrations. Volatiles, hypobaric atmospheres, salts, minerals, plant phenolics, hot water, wax and salicylic acid have resulted in good control methods with promising applications.

In Mexico, Dahlia flowers are commonly consumed in different type of dishes; however, there are no reports on characteristics as a functional food. Proximate composition, minerals, vitamin C, phenolic compounds, total anthocyanins, carotenoids and antioxidant activity of dahlia flowers were studied. In general, the highest values for the content of phenolic compounds, anthocyanins and antioxidant capacity were found in the purple dahlia (127.5 mg AG.g -1, 257.5 mg pelargonidin.100 g -1 and 24% of inhibition respectively). The type and concentration of phenolic compounds varied according to the color of the flower. The highest phenolic compound value was for hesperidin (398.9 mg.g -1), while the most detected phenolic compounds in the flowers were gallic and caffeic acids. Based on these results, we can recommend the consumption of dahlia flowers as functional food because it provides phenolic compounds (specially the dark-colored dahlia flowers, since they had the highest phenolic composition and antioxidant activity) En México, las flores de dalia son comúnmente consumidas en diferentes tipos de platillos. Sin embargo, no existen reportes sobre sus características como alimento funcional. En esta investigación se estudió la composición proximal, el contenido de minerales, vitamina C, compuestos fenólicos, antocianinas totales, carotenoides y actividad antioxidante de flores de dalia. En general, los valores más altos para el contenido de compuestos fenólicos, antocianinas y capacidad antioxidante se encontraron en las flores de dalia color púrpura (127.5 mg AG∙g-1, 257.5 mg de pelargonidina∙100 g-1 y 24 % de inhibición, respectivamente). El tipo y la concentración de cada compuesto fenólico variaron de acuerdo al color de la flor. El valor más alto de compuesto fenólico fue para hesperidina (398.9 mg∙g-1). Los compuestos fenólicos detectados con mayor frecuencia en las flores fueron los ácidos gálico y cafeico. Con base en estos resultados, se puede recomendar el consumo de flores de dalia como un alimento funcional porque aportan compuestos fenólicos (especialmente las flores de coloración oscura, ya que presentaron la más alta composición fenólica y capacidad antioxidante)

In Mexico, Dahlia flowers are commonly consumed in different type of dishes; however, there are no reports on characteristics as a functional food. Proximate composition, minerals, vitamin C, phenolic compounds, total anthocyanins, carotenoids and antioxidant activity of dahlia flowers were studied. In general, the highest values for the content of phenolic compounds, anthocyanins and antioxidant capacity were found in the purple dahlia (127.5 mg AG.g -1, 257.5 mg pelargonidin.100 g -1 and 24% of inhibition respectively). The type and concentration of phenolic compounds varied according to the color of the flower. The highest phenolic compound value was for hesperidin (398.9 mg.g -1), while the most detected phenolic compounds in the flowers were gallic and caffeic acids. Based on these results, we can recommend the consumption of dahlia flowers as functional food because it provides phenolic compounds (specially the dark-colored dahlia flowers, since they had the highest phenolic composition and antioxidant activity) En México, las flores de dalia son comúnmente consumidas en diferentes tipos de platillos. Sin embargo, no existen reportes sobre sus características como alimento funcional. En esta investigación se estudió la composición proximal, el contenido de minerales, vitamina C, compuestos fenólicos, antocianinas totales, carotenoides y actividad antioxidante de flores de dalia. En general, los valores más altos para el contenido de compuestos fenólicos, antocianinas y capacidad antioxidante se encontraron en las flores de dalia color púrpura (127.5 mg AG∙g-1, 257.5 mg de pelargonidina∙100 g-1 y 24 % de inhibición, respectivamente). El tipo y la concentración de cada compuesto fenólico variaron de acuerdo al color de la flor. El valor más alto de compuesto fenólico fue para hesperidina (398.9 mg∙g-1). Los compuestos fenólicos detectados con mayor frecuencia en las flores fueron los ácidos gálico y cafeico. Con base en estos resultados, se puede recomendar el consumo de flores de dalia como un alimento funcional porque aportan compuestos fenólicos (especialmente las flores de coloración oscura, ya que presentaron la más alta composición fenólica y capacidad antioxidante)

The fungus Fusarium oxysporum f. sp. gladioli is one of the main pathogenic microorganisms of the ornamental genus Gladiolus. The attack of this microorganism includes corms and different plant phenological stages. In this study, different microscopic techniques and fluorochromes were used to evaluate the effect of J. curcas oil and acylglycerides, namely trilinolein, triolein, monomyristin and dimyristin, on the morphology, membrane integrity (%), viability (%) and germination (%) of F. oxsporum f sp. gladioli. Phase-contrast optical photomicrographs and scanning microscopy showed that J. curcas oil and the triglycerides triolein and trilinolein caused the formation of numerous vacuoles, alterations in the morphology of the outer covering of the mycelium and conidia, and inhibition of membrane activity in the fungus during 24h of incubation. The fluorochromes used detected no permanent damage to the viability of the conidia. The high germination percentage of the conidia of Fusarium oxysporum f. sp. gladioli indicates that the damage caused by the application of the treatments was fungistatic rather than fungicidal and did not cause cell death.

"Some strains of Fusarium oxysporum are pathogenic to different plant species during their pre- and postharvest stages and are responsible for serious economic losses. Management of this fungus is usually with the aid of environmentally-harmful chemicals. However, other biodegradable compounds such as isothiocyanates (ITCs) have demonstrated their nematicidal, bactericidal and fungicidal potential. In this research, the in vitro fungitoxic effect of ITCs of allyl, benzyl, phenyl, phenylethyl and propyl at concentrations of 0, 0.1, 0.3, 0.5, 1.0, 1.5 and 2.0 μl L-1 was tested on various isolates of F. oxysporum obtained from gladiolus corms, jatropha seeds, mango leaves, papaya and coahuayote fruit. Daily mycelial growth and conidial germination of these five isolates was evaluated at different incubation period. To verify the fungistatic or fungicidal response, the ITCs were removed and the fungi were re-grown only in nutrient media. As average, conidia of F. oxysporum were more sensitive to the ITCs than mycelium. At the end of the incubation period, there were significant differences (P < 0.05) in mycelia growth of the ITC-treated fungi compared to the untreated ones. The F. oxysporum isolates that were the most sensitive to the benzyl ITC were those obtained from mango leaves and coahuayote fruit. The mango isolate was also very sensitive to phenylethyl ITC. At concentrations ranging from 1.0 to 2.0 μl L-1, the allyl ITC also suppressed the growth of F. oxysporum isolated from papaya and coahuayote fruit. Except for the phenyl ITC in the coahuayote fruit, conidial germination of F. oxysporum did not occur under the influence of the remaining ITCs, whilst in the control treatment germination reached 100%. As average, the concentration applied did not influence the growth of the fungi. Once the source of the ITCs was removed from the Petri plate re-growth and germination took place in all fungi. In conclusion, the ITCs tested differed in bioactivity and the mycelium and conidia of the different F. oxysporum isolates varied in their susceptibility and tolerance to these compounds."

"Los recubrimientos son matrices continuas formuladas a base de lípidos, proteínas o carbohidratos o mezclas de estos componentes, que les confieren diferentes propiedades fisicoquímicas. Un carbohidrato utilizado para la formulación de los recubrimientos comestibles es el quitosano, el cual reduce el crecimiento de hongos y bacterias. Los recubrimientos pueden servir como vehículos para un amplio rango de aditivos, incluyendo compuestos antimicrobianos, con la finalidad de proporcionarles mayores atributos como es el control de microorganismos. Entre los aditivos naturales están los aceites esenciales. Se tiene amplia evidencia que los aceites esenciales extraídos de diferentes plantas presentan inhibición contra hongos y bacterias. Al formular recubrimientos comestibles con quitosano y adicionar a las formulaciones productos como los aceites esenciales, se evita el desarrollo de microorganismos, se prolonga la vida de anaquel de los productos agrícolas, y se mantienen las propiedades sensoriales de éstos. En este artículo se llevó a cabo una revisión de literatura sobre el tema de recubrimientos comestibles y sus principales componentes sobre la fisiología del producto. Asimismo, se revisó literatura con respecto al efecto de la elaboración de recubrimientos con quitosano y la incorporación de aceites esenciales sobre su actividad en diferentes microorganismos patógenos."

Extractos crudos de hojas y tallos de 40 especies diferentes de plantas del estado de Morelos, México, se utilizaron para comparar la germinación conidial de dos aislamientos de Colletotrichum gloeosporioides, los cuales se obtuvieron de frutos de papaya con síntomas de antracnosis, provenientes del estado de Guerrero y Veracruz, México. En general, el mejor efecto antifúngico se observó con el extracto crudo de huele de noche (Cestrum nocturnum) y chirimoya (Annona cherimola) para ambos aislamientos después de 14 ó 18 h de incubación y determinado por el método de microscopía óptica (MMO) y el método de espectrofotometría (ME). Los conidios de ambos aislamientos incubados en los extractos crudos de Origanum majorana, Carica papaya, Citrus aurantium, Citrus aurantifolia, Bougainvillea spectabilis, Justicia spicigera, Petroselinum sativum, Parthenium hysterophorus, Schinus molle y Ricinus communis mostraron porcentajes de germinación menores de 61% por MMO y menores de 56% por ME. Los 28 extractos crudos restantes no mostraron algún efecto antifúngico. La germinación de conidios varió de acuerdo al extracto vegetal, aislamiento, tiempo de incubación y método de evaluación.

"The antifungal effects of seed powders, extracts, and secondary metabolites of Pachyrhizus erosus from Morelos state, Mexico, was investigated using mycelial inhibition bioassays on Colletotrichum gloeosporioides, Fusarium oxysporum, and Rhizopus stolonifer. In general, a dose-effect curve for concentrations 0.5, 2.0, 5.0, and 10 mg/ml was observed on the fungi evaluated. Seed powders had an inhibitory effect on C. gloeosporioides; nevertheless, stimulation effects were observed on F. oxysporum, and R. stolonifer at 0.5, and 5.0 mg/ml, respectively. All extracts, hexane, dicloromethane, and acetone, significantly inhibited the three fungi at 2.0, 5.0, and 10 mg/ml. The greatest fungistatic effects were achieved with dicloromethane extract on R. stolonifer (-64.97%), on F. oxysporum (-37.8%), and C. gloeosporioides (-36.4%). These results suggest that fungicidal compounds might be extracted with this solvent. The dicloromethane extract was subjected to chromatography isolating rotenone (1), erosone (3), paquirrizone (5), dolineone (6), and paquirrizine (4). The isoflavone dehydroneotenone (2) was isolated from the acetone extract. The identity of the components was determined by infrared, ultraviolet, 1H, and 13C nuclear magnetic resonance. These secondary metabolites significantly inhibited the three fungi at 250 µg/ml. The best fungicidal effect was achieved with rotenone on R. stolonifer, with pachyrrizine on F. oxysporum, and dehydroneotenone on C. gloeosporioides."

"Aqueous extracts of leaves and stems of Achras sapota, Annona reticulata, Bromelia hemisphaerica, Carica papaya, Citrus limon, Chrysophylum cainito, Dyospiros ebenaster, Mangifera indica, Persea americana, Pouteria sapota, Spondias purpurea, and Tamarindus indicus from the state of Morelos, Mexico were tested for their antifungal activity against Colletotrichum gloeosporioides in in vitro and in vivo experiments. Papaya and mango fruit were dipped in extracts, inoculated with C. gloeosporioides, and stored for seven days at room temperature to evaluate percentage infection and severity, solid solubles concentration (SSC), and fruit mass loss. Differences were found between the inhibitory effects in vitro and in vivo. Leaf extracts from C. limon and P. americana totally inhibited growth of C. gloeosporioides in vitro. Leaf extracts of C. papaya completely inhibited postharvest rots of papaya, while leaf and stem extracts of D. ebenaster had an adequate fungicidal effect when applied to mango. Infection severity of papaya ranged from 0 to 50% of the fruit surface, while in mango only 25% of the surface was affected. Overall, infection severity was reduced for both papaya and mango when dipped in extracts. SSC and fruit mass loss varied among plant extracts; however, extracts did not affect fruit quality during storage. "

"Powders of Pithecellobium dulce leaves, fruit and seeds sequentially extracted with hexane-dicloromethane, acetone, and methanol-water were evaluated on mycelial growth of Alternaria sp., Botrytis cinerea, Colletotrichum gloeosporioides, Fusarium oxysporum, Penicillium digitatum, Pestalotiopsis sp. and Rhizopus stolonifer. In comparison to fruit and leaf powders, seeds had the highest fungistatic activity against the fungi tested. In general, a dose-effect curve was observed for the three concentrations (0.5, 2.0 and 5.0 mg/ml) evaluated. However, for P. digitatum and Alternaria sp., the lowest and highest concentrations respectively, increased mycelial growth. Depending on concentration, leaf and fruit powders inhibited or increased mycelial growth. For Pestalotiopsis sp.,P. digitatum, F. oxysporum, Alternaria sp., and R. stolonifer mycelial growth increased on seed residues (10 mg/ml), after hexane- dicloromethane, acetone, and methanol-water extractions of seed powder, suggesting that fungistatic compounds were removed by the dissolvent used. The hexane-dicloromethane extract was subjected to column chromatography, obtaining 13 fractions with similar pattern, which were evaluated using the mycelial growth responses of F. oxysporum, P. digitatum and R. stolonifer. Eleven and nine fractions inhibited F. oxysporum and R. stolonifer development, respectively. P. digitatum was the fungus least affected by all fractions. Preliminary analysis of the most active fraction by nuclear magnetic resonance indicated the presence of a tryacyl glycerol. "

"Bautista-Baños, S., Barrera-Necha, L.L., Long, P.G., Ganesh,S., and Cheah, L.H. 2001. Inoculum variables affecting pathogenicity of Botrytis cinerea infection of kiwifruit. Revista Mexicana de Fitopatología 19:161-167.In vitro spore germination of Botrytis cinerea isolates from diseased blueberries, camellia, grapes, kiwifruit andstrawberries grown on malt agar (MA) for 7 or 28 days werecompared. Pathogenicity of grape, kiwifruit and strawberryisolates was tested on kiwifruit at Massey University and atthe New Zealand Institute for Crop and Food Research(Levin). Average spore germination was 74.4% when the suspension concentration was 5.9 x 104, and only 62.8% whenit was 1.5 x 106. The percentage germination on agar did not indicate relative pathogenicity on kiwifruit, and there was no significant difference in disease incidence of fruit inoculatedwith different isolates after 12 weeks of coolstorage at Levin.At Massey University, the grape and kiwifruit isolates causedmore disease than the other isolates. Botrytis storage rot was proportional to inoculum concentration. There was nosignificant effect of culture age. At Massey University; thehighest disease incidence was obtained from inoculum produced on MA, whereas at The Crop and Food ResearchInstitute it was from inoculum produced on autoclavedkiwifruit leaves."

To evaluate the fungicide properties of cultivated plant species from the State of Morelos, Mexico, aqueous extracts and powders from leaves of 20 different plant species were prepared to evaluate their in vitro effect on development of the postharvest phytopathogenic fungi: Alternaria spp., Fusarium spp., Pestalotiopsis spp. and Rhizopus spp. The parameters evaluated were mycelial growth, sporulation and mycelial dry weight. Results indicated that the fungistatic activity was diffferent between aqueous extracts or powders and the species evaluated. A selective fungistatic effect depending on plant species and pathogen was evidenced as well. Pithecellobium dulce was the main plant species showing fungistatic effects against the development of the fungi tested. Other plant species with promising fungicide or fungistatic activity properties were Achras sapota, Annona cherimola, Casimiroa edulis, Citrus limon, Crataegus mexicana, Carica papaya, Psidium guajava, Persea americana and Spondias purpurea. In situ studies are recommended to continue this research