Hass avocadoes are one of the most popular fruits consumed worldwide because of their nutritional and nutraceutical content. Nevertheless, these fruits are susceptible to phytopathogen attacks that decrease fruit quality during the postharvest period. Herein we present the results of the in situ fungistatic activity of four hybrid films (FT1–FT4) manufactured with chitosan and different concentrations of the essential oil of thyme (TvEO). The films were evaluated as biodegradable materials to prevent fruit decay triggered by Clonostachys rosea which is considered an emergent phytopathogen of this crop. The in situ fungistatic strength, spectroscopic properties (FT-IR), optical features (transmittance/opacity), and consistency obtained by microscopic analysis (SEM), indicated that the films FT3 and FT4 possessed the best physicochemical properties to protect Hass avocadoes against the soft rot produced by C. rosea. Avocadoes treated with the films FT3 and FT4 significantly (p < 0.01) conserved fruit firmness and nutritional composition (protein, fat, fiber, and reducing sugars) as well as the nutraceutical content (oleic, palmitoleic, linoleic, and palmitic acids) of infected avocados for 21 days. Our results validate the potential use of the films FT3 and FT4 to prevent the soft rot caused by C. rosea and to improve the shelf life of Hass avocadoes.

The present article describes the chemical composition and biological activities of the essential oils of B. glabrifolia leaves obtained in four consecutive years (2015-2018). The essential oils contained α-terpineol (17.9-29.7 %), α-terpinene (12.6-17.4 %), limonene (14.9-26.8 %) and β-pinene (2.1-16.7 %) as the most abundant volatiles. The essential oils and these volatiles showed a significant adulticide activity (p<0.01; LC <100 μg mL ) on the maize weevil (Sitophilus zeamais) with a 100 % mortality rate within a period of 5 h. Also, the essential oils showed a strong antibacterial activity on Enterococcus faecalis ATCC 29212 (MIC, 132.7-173.6 μg mL ) and Helicobacter pylori ATCC 43504 (MIC, 74.8-199.2 μg mL ). The assessment of the main volatiles revealed α-terpineol as the principal antibacterial agent (MIC, 78.6-149.7 μg mL ). Similarly, the essential oils exhibited a substantial in vitro antiproliferative activity on the human prostate cancer cell lines PC-3 (LC , 15.2-19.4 μg mL ), the human ovarian carcinoma cell lines OVCAR-3 (LC , 27.3-53.7 μg mL ) and the myelogenous leukemia cell lines K-562 (LC , 32.4-75.9 μg mL ). α-Terpineol (LC , 32.4-75.9 μg mL ) exhibited the strongest antiproliferative effect on these cancer cell lines (LC , 22.4-48.1 μg mL ).

Avocado root rot caused by the oomycete Phytophthora cinnamomi is a severe disease that affects avocado production in Mexico and worldwide. The use of biological control agents such as Trichoderma species isolated from places where the disease is always present, represents an efficient alternative to reduce losses. Thus, the objective of this research was to evaluate the biocontrol ability of 10 endophytic Trichoderma spp. strains against P. cinnamomi tested both in vitro and in the greenhouse. The endophytic Trichoderma spp. were recovered from Persea americana and Cinnamomum verum roots, isolated and purified on potato–dextrose–agar medium. Ten strains were identified by phylogenetic reconstruction of the internal transcribed spacer region of rDNA sequences as T. asperellum (T-AS1, T-AS2, T-AS6, and T-AS7), T. harzianum (T-H3, T-H4, and T-H5), T. hamatum (T-A12), T. koningiopsis (T-K8 and T-K11), and P. cinnamomi (CPO-PCU). In vitro dual-culture assay, the percentage of inhibition of radial growth (PIRG) between Trichoderma spp. and P. cinnamomi strains was measured according to the Bell’s scale. PIRG results indicated that T-AS2 reached the highest value of 78.32%, and T-H5 reached the lowest value of 38.66%. In the greenhouse, the infection was evaluated according to the percentage of disease incidence. Plants with the lowest incidence of dead by avocado root rot were those whose seedlings were inoculated with T-AS2 and T-AS7, resulting in only 5% death by root rot caused by P. cinnamomi. The disease incidence of seedlings with wilt symptoms and death decreased more than 50% in the presence of Trichoderma spp. Relying on the results, we conclude that T. asperellum and T. harzianum contribute to the biocontrol of soil-borne pathogenic oomycete P. cinnamomi.

Diversity and bioclimatic profiles of Vanilla spp. (Orchidaceae) in Mexico. The genus Vanilla comprises around 110 species distributed throughout Earth's tropical regions, with the largest number of reported species growing in the American continent. Vanilla farming is associated with many Mexican cultures such as the Totonac, Mayan, Chinantec, and Mazatec, among others. Currently, this crop is threatened by technical, social, ecological, and climatic conditioning factors, limiting its production and the preservation of wild and cultivated species. It is therefore necessary to ascertain the current diversity status of each of these species, as well as some of their main bioclimatic profile indicators, in order to help decision-making, aimed at preserving and genetically improve these species. During 2008, we gathered data from IPN, MEXU, and XAL herbaria, as well as from CONABIO's World Information Network on Biodiversity (REMIB), the Global Biodiversity and Information Facility (GBIF), and we also used data from live access to BUAP's vanilla germplasm bank, obtained between 2008 and 2014. Distribution maps were generated using a geographical information system. Bioclimatic profiles for each species were obtained considering 19 WorldClim variables and altitude at a spatial resolution of approximately 1 Km 2 . Variance, Mean, and standard deviation for each of the 19 variables were calculated at each of the registered points. Extreme environmental condition intervals (minimum, average, and maximum) were also obtained. In order to determine the most important distribution variables of the species, we performed a principal component analysis and carried out Kruskal-Wallis and Dunn's tests on the variables identified as significant. Results indicated records for V. planifolia, V. pompona, V. insignis, V. inodora V. odorata, V. cribbiana, and V. sprucei in Mexico, distributed throughout nine states in the country. V. planifolia presented wide intervals of temperature and rain precipitation, while V. pompona, V. odorata, V. insignis and V. inodora presented intermediate intervals. The amplitudes of extreme data for each species can be considered in locating areas where ex situ regional preservation strategies could be put in place, as well as in establishing areas for cultivation. The bioclimatic profile we found, allows for an indirect inference of each species' genetic condition, which could be used in genetic improvement programs; for instance, V. odorata grows at high altitudes and tolerates low temperatures, while V. inodora tolerates high temperatures, and V. odorata, V. pompona and V. planifolia tolerate low rain precipitation. Rev. Biol. Trop. 65 (3): 975-987. Epub 2017 September 01.

Los problemas y limitaciones del control de enfermedades fúngicas mediante el uso de fungicidas hacen que el control biológico de hongos fitopatógenos se presente como un método de control alternativo en la producción de tomate (Lycopersicon esculentum M.) en invernadero, la cual está limitada por la incidencia del oomycete Phytophthora capsici, siendo una de las enfermedades más destructivas a nivel mundial. El objetivo de este trabajo fue evaluar el efecto de cuatro bio-fungicidas elaborados a base de cepas nativas del genero Trichoderma contra P. capsici en la producción de tomate, denominado en la región "jitomate" variedad Ramses, en condiciones de invernadero en sistema de camas. El biofungicida a base de T. harzianum presentó los mejores resultados promedios con una supervivencia de 76,4% y un rendimiento promedio de 27% mayor al grupo control. Todos los tratamientos con biopreparados presentaron mayor altura de la planta y biomasa final que el tratamiento control. Así, el tratamiento control mostró una mortalidad del 54%, con un rendimiento promedio de 11% menor al de los biopreparados con cepas nativas de Trichoderma spp. y mayor al tratamiento inoculado con P. capsici, que presentó la mayor incidencia "enfermedad" (40%), la menor supervivencia (26,3%) y un descenso de rendimiento de fruto del 64% respecto al control.