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Background. Ardisia compressa Kunth, is a wild species native from tropical evergreen forests of Mexico, it produces fruits with phytochemical, ecological and dietary potencial. Its fruits are appreciated by people from local communities. However, in Mexico there are no studies that allow knowing the state of its phenotypic diversity. Objective. Characterize the morphological diversity of A. compressa populations from Chiapas state, Mexico. Methodology. Ninety individuals of nine wild populations of A. compressa were evaluated using 45 morphological traits (16 qualitative and 29 quantitative). The qualitative data were subjected to descriptive analysis and quantitative data were used in an analysis of variance (ANOVA) and finally the qualitative and quantitative data were analyzed simultaneously by means of a multivariate analysis with the Ward-MLM Method. Results. The qualitative traits showed phenotypic variability in the characteristics of leaf and fruit color. The quantitative data showed significant differences (P≤ 0.05) in all traits evaluated. The results of the principal component analysis (PCA) and cluster analysis (UPGMA) grouped the populations into three morphological groups differentiated by the similarity of the morphological traits of the populations and not by their geographical origin. Implications. The results in this study should be considered to implementing strategies of plant production and conservation of A. compressa. Conclusion. A wide phenotypic variability was found organized into three morphological groups defined base on characteristics of tree height, number of fruits, number of flowers and ratio of length to thickness leaf. The quantitative traits allowed us to observe the greatest morphological variability in the populations of A. compressa.

Hydrocarbon contamination cause serious environmental damage and human health problems, therefore, to resolve this problem has been proposed diversely remediation techniques friendly with the environment i.e. bioaugmentation, biostimulation, natural attenuation and phytoremediation. Among options, the phytoremediation causes minimum alterations to soil, low cost, it has proved good efficiency and gained public acceptation. In the present study, the capacity of Mimosa pigra to restore a contaminated soil with both anthracene and phenanthrene was evaluated, along with the soil physicochemical changes due to both plant and contaminant presence in the soil. A silt-loam contaminated soil with 100 mg kg-1 (dry weight) anthracene and 200 mg kg-1 (dry weight) phenanthrene was used in all three treatments: Contaminated soil with M. pigra (C1), contaminated soil without M. pigra (C2), and not contaminated soil with M. pigra (C0) as control. After 70 days of experimentation both biomass and height of M. pigra was not affected due to soil contaminants. There was no difference among treatments for some physicochemical characteristics e.g. soil pH, electrolytic conductivity, soil-texture, and total nitrogen content throughout the experiment. M. pigra increased the soil water holding capacity after 50 and 70 days of the experiment, however, total organic carbon content was lower after 70 days compared to the control treatment. The higher contaminant removal rate was before 7 days of experimentation for all treatments. Anthracene and phenanthrene content were lower in treatments with the presence of M. pigra: 92% of phenanthrene and 80% of anthracene were removed in C1 while nearly 77% of phenanthrene and 60% of anthracene were removed in C2. This suggest a greater removal of contaminants using M. pigra. Total removal of contaminants was not achieved. However, M. pigra was able to accumulate both compounds, showing the M. pigra capability for bioremediation use in contaminated soils.

This work was conducted with the objective to evaluate the effect of vermicompost application on chemical characteristics, energetic parameters and amino acids profile of hybrid race corn grain cultivated under open-field and rained conditions. The experiment was accomplished under a randomized complete design with three repetitions. Three treatments were evaluated: 1) Maize after inoculation with a commercial mycorrhizal arbuscular fungi mixture (Tec Myc 60®) plus vermicompost (V+M); vermicompost (V) and chemical fertilization (CF). Starch content in grain was 1.9% higher in V+M treatment in comparison with chemical, whereas crude protein, ether extract, crude fiber, acid detergent fiber, neutral detergent fiber, total phosphorous and phytic phosphorous were not different between treatments. Energetic parameters were not different between three treatments. 17 amino acids were evaluated of wich only tryptophan, leucine, valine, histidine and aspartic acid were higher in CF and V treatments in comparison with V+M treatment. In conclusion, it is possible to cultivate maize using vermicompost as fertilizer because chemical characteristics, energetic parameters and amino acids profile in maize grain were not affected compared with the maize cultivated with vermicompost added with biofertilizers (V+M) or with corn cultivated with chemical fertilizers (CF).

In the present study, the hexane, acetone and methanol extracts of stem, branches and roots from Crotalaria longirostrata were evaluated for their antifungal activity against Fusarium sp., Fusarium verticillioides and Aspergillus flavus. The variables analyzed were inhibition halos, mycelial growth inhibition, sporulation and minimum inhibitory concentration. Phytochemical analysis revealed the presence of saponins, coumarins, anthrones, anthraquinones, flavonoids and alkaloids on different organic extracts. The hexane extract showed zones of inhibition between 6.3 and 10.5 mm. The mycelia growth and sporulation of A. flavus were reduced to 90% with methanol extract. The minimum inhibitory concentration values obtained with hexane extracts were 6.75 mg mL-1 and with methanol extracts were 50 and 25 mg mL-1 for Fusarium strains. This is the first study reporting of phytochemical composition and biological activity of C. longirostrata that could be used as a natural alternative to control in vitro of certain important pathogenic fungi.

Current protocols for Agave americana L. micropropagation have limited commercial application due to the low number of plants produced by explant. Indirect organogenesis could be an alternative, however is necessary to optimize plant growth regulators for plantlet number maximization. The objective of this work was to optimize 2,4-dicholorophenoxyacetic acid (2,4-D) and 6-benzyl adenine (BA) concentrations on the induction of A. americana embryogenic callus from apical meristem as explant for maximized the number of shoots per callus using a response surface experimental design. MS medium containing 30 g l-1 sucrose amended with 0.11,0.18, 0.45 or 2.26 μM 2,4-D, and 11.0, 22.0, 38.2 or 44.0 μM BA was used. Nine treatments with three repetitions was applied and number of shoots per callus were monitored after 4, 16, 20 and 36 weeks. In vitro rooting of shoot was done in MS medium added with indole butyric acid (IBA). A maximum number of plantlets per explant (74) was obtained with 2.26 μM of 2,4-D and 38.2 μM BA. In conclusion, the indirect organogenesis of A. americana L. could be an alternative for obtain plantlets for propagation commercial purposes

The tropical legume Acaciella angustissima inoculated with or without Sinorhizobium mexicanum ITTG R7T strain was cultivated in an aluminium (Al) spiked soil to study its tolerance towards this metal. Seedlings of A. angustissima were grown in soil with 0, 2, 4 or 6 mg Al kg-1. The effect of Al and inoculation on growth, nodulation, and nitrogen and tannins content in the plants was monitored. Height and total and dry root weight of plantlets decreased significantly when soil was spiked with Al, but increased when inoculated. Al decreased the number of nodules. Inoculum increased total N and tannin content of the plantlets. It was found that Al reduced the growth of the tropical leguminous N2-fixing shrub A. angustissima, while inoculation with S. mexicanum ITTG R7T stimulated its growth and increased its tannin and N content.La leguminosa tropical Acaciella angustissima inoculada con o sin la cepa Sinorhizobium mexicanum ITTG R7T fue cultivada en un suelo tratado con (Al) para estudiar la tolerancia a este metal. Las plantas de A. angustissima fueron crecidas en el suelo con 0, 2, 4 y 6 mg de Al kg-1. Se hizo un seguimiento del efecto de Al e inoculación en el crecimiento, la nodulación, el contenido de nitrogeno y el contenido de taninos en las plantas. La altura, el peso seco total y el peso seco de la raíz de las plantas decrementó significativamente cuando el suelo fue tratado con Al, pero incrementó cuando fue inoculado. El Al disminuyó el número de nódulos. El inóculo incrementó el N total y el contenido de taninos de las plantas. En este experimento fue encontrado que el Al reduce el crecimiento de la leguminosa arbustiva tropical fijadora de N2 A. angustissima, mientras la inoculación con S. mexicanum ITTG R7T estimula el crecimiento e incrementa el contenido de taninos y nitrógeno.

El objetivo del trabajo fue evaluar el efecto de dos hongos micorrízicos arbusculares (HMA) a diferentes concentraciones de fósforo sobre la sobrevivencia y el crecimiento de plántulas de pina {Ananas comosus (L.) Merr.) obtenidas por micropropagación. Las plántulas se multiplicaron masivamente en cultivos in vitro y se aclimataron gradualmente bajo un esquema de estrés por temperatura en tres etapas secuenciales. Los efectos de los HMA y el fósforo no fueron significativos sobre la sobrevivencia y la altura de las plántulas, sin embargo, Glomus claroideum estimuló que las plántulas tuvieran mayor número de hojas y peso seco. Los resultados sugieren que la altura de las plántulas fue mayor cuando fueron cultivadas con G. claroideum y 0,9 mM de fósforo.The objective of this work was to assess the effect of two arbuscular mycorrhizal fungi (AMF) at different phosphorus concentrations on survival and growth of pineapple {Ananas comosus (L.) Merr.) plantlets obtained for micropropagation. Plantlets were multiplied for in vitro cultures and were acclimatized under three sequential steps. The effects of AMF and phosphorus were not significant on plantlet survival and plantlet height, however Glomus claroideum stimulated that the plantlets were with higher leaves number and dry weight. The results demonstrated that plantlet growth was maximized with G claroideum and phosphorus 0.9 mM.

The effects of different inorganic fertilizers and rhizobial inoculation on shoot height, total shoot and root dry weight, nodule number, total shoot nitrogen, nitrogenase activity and tannic acid content of Acaciella angustissima (Mill.) Britton & Rose were investigated in the laboratory. Seedlings were grown in a climate chamber in glass tubes containing sterilized mixture of vermiculite and peat moss, and treated with combinations of nitrogen (N) at 45 mg plant¹, phosphorus (P) at 30 mg plant¹, potassium (K) at 20 mg plant¹ and inoculated with the bacterium Sinorhizobium mexicanum. The combined applications of N, P or K to uninoculated plants increased shoot height and dry weight as compared to the unamended plantlets. The tannin content in uninoculated plants was highest when amended with P+K. Treatment had a significant effect on plant growth, nodulation and tannin content varied. The plants treated with P + K + S. mexicanum had significantly longer shoot height, total shoot and root dry weight, nodule number, total shoot nitrogen, nitrogenase activity and tannic acid content in comparison with unamended plants. It was found that N reduced number of nodules, tannin content and nitrogenase activity of A. angustisisma. As such, farmers should refrain from applying N fertilizer, but could apply P and K to maximize tannin production in A. angustissima.Se investigaron en el laboratorio los efectos de diferentes fertilizantes inorgánicos y la inoculación rizobial sobre la altura de planta, peso seco total de planta, peso seco de raíz, el número de nodulos, el nitrógeno total de la planta, la actividad de la nitrogenasa y el contenido de ácido tánico de Acaciella angustissima (Mili.) Britton & Rose. Las plántulas fueron crecidas en una cámara climática en tubos de vidrio conteniendo una mezcla de vermiculita y turba, y tratadas con las combinaciones de nitrógeno (N) en 45 mg planta"¹, fósforo (P) en 30 mg planta"¹, potasio (K) en 20 mg planta"¹ e inoculado con la bacteria Sinorhizobium mexicanum. La combinación de las aplicaciones de N, P o K en plantas sin inocular incrementa la altura y el peso seco de planta en comparación con las plantas sin tratamiento. El contenido de taninos en plantas no inoculadas fue el más alto cuando suplementamos con P+K. El tratamiento tuvo un efecto significativo sobre el crecimiento de planta, modulación y el contenido de tanino variado. Las plantas tratadas con P + K + S. mexicanum tuvieron significativamente mayor altura de planta, peso seco total de planta, peso seco de raíz, el número de nodulos, nitrógeno total de planta, actividad de la nitrogenasa y contenido de taninos en comparación con las plantas sin suplementar. Fue encontrado que el N reduce el número de nodulos, el contenido de taninos y la actividad de la nitrogenasa de A. angustisisma. Como tal, los agricultores deberían abstenerse de aplicar el fertilizante de N, pero podrían aplicar P y K para maximizar la producción de tanino en A. angustissima.