Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Objective: The objective was to assess the growth and accumulation of biomass in seedlings of three forest species Cedrela odorata, Tabebuia chrysantha (Threatened species) and T. rosea, under bio-based and synthetic fertilization, as well as their rhizosphere effect. Design/methodology/approach: A completely randomized design with four replications was established and three treatments were evaluated for each forest species: T1, mycorrhizae based biofertilizer; T2, biofertilizer based on Azospirillum sp.; T3, synthetic slow release fertilizer, using from week one to four the commercial starter formula 10-15-5, applying 50ppm / plant; while from week 10 to 12, 100 ppm / plant of Nitro 30-0-0 were used, with their corresponding control. The growth variable was measured by height in a ten-day interval and the biomass accumulated at 12 weeks was estimated. Finally, rhizospheric soil samples were taken from each treatment, by species and free-living nitrogen fixing bacteria (FLNB) in Congo red agar. Results: The biofertilizer based on Azospirillum sp. improved plant growth and microbiological quality of the rhizospheric soil of Cedrela odorata and Tabebuia rosea; while with T. chrysantha, no statistical differences were found between the different types of fertilization. FLNB growth was favored by biofertilizers. Limitations on study/implications: The study lasted only three months, so it is suggested to analyze long-term variables, as well as their response in the field. Findings/conclusions: Biofertilization can be an alternative for the growth of forest species such as Cedrela odorata and Tabebuia rosea.

Objective: To describe morphologic traits and imbibition stages in seeds from three accessions of Matthiola incana. Design/methodology/approximation: Seeds were analysed from Nieve, Rosita and Uva genotipes, which correspond to the genus Matthiola and species incana. In the first assessment, weight and colour was determined in a thousand seeds. The area, perimeter, length (major axis), width, centric angle, elongation (length/width) and round degree were obtained by means of processing digital images. Analysis of variance was performed to the data followed by a multiple comparison of means by the Tukey procedure. For the imbibition test, fifty seeds of each genotype were immersed in water and evaluated every 24, 48, 72 and 164 hours in order to know the absorption dynamic and determine the time of the imbibition sub and phases.  Results: Physical description in Nieve seeds show a moderate orange colour and thousand seeds weight 0.218 g; Rosita seeds have a moderate orange yellowish colour and thousand seeds weight 0.1902 g; Uva seeds show a colour from greyish to dark brown with a weight of 0.1272 in thousand seeds. Nieve seeds show greater morphologic dimensions than Rosita and Uva seeds, but the three genotypes show a similar trait in the form type. During the imbibition test of each genotype follow a progressive rate until stage three, where the imbibition behaviour is synchronised with the radical protrude emergency to 164 h after the test was initiated.  Study limitations/implications: Seeds show a different size, therefore great samples are difficult to handle at the imbibition moment. Findings/conclusions: It is determined from the three accessions that seeds from Matthiola incana species have greater morphologic traits than other species from the same genus. Two phases were identified during the phase two, the first one was known as the moment of solute explosion and the second one was known as the recovery of lost solutes.

Objetivo: comparar las ganancias del cultivo de agave en su uso tradicional como materia prima para la producción de tequila y en su valoración innovadora empleada para obtener inulina en los estados de Jalisco, Guanajuato, Michoacán y Nayarit, México considerando el riesgo de los precios y evaluación del proyecto ante escenarios de incertidumbre.Diseño/metodología/aproximación: El primer paso fue calcular las tasas de crecimiento continuas del precio de cada entidad para el período 2005-2017. Se realizaron dos evaluaciones para las entidades objeto de estudio, una con metodologías tradicional (empleando el Valor Actual Neto, VAN) para valorar el uso del agave en la obtención del tequila, y otra cimentada en opciones reales con árboles binomiales y fórmulas de Black y Scholes que permiten considerar el riesgo y evaluación del proyecto ante escenarios de incertidumbre dada su innovación.Resultados: La evaluación tradicional mostró que su uso para obtener tequila es viable (rentable); sin embargo, mediante opciones reales una vez que se diferencia el uso del agave de forma innovadora, el valor del proyecto aumentó en las cuatro entidades. Limitaciones del estudio/implicaciones: No se identificaron los costos y producción de las entidades estudiadas a un plazo mayor.Hallazgos/conclusiones: La diferenciación del agave empleándolo para la producción de inulina incrementa las probabilidades de enfrentar positivamente un futuro incierto. Palabras clave: innovación, volatilidad, evaluación de proyectos tradicional, árboles binomiales, fórmulas de Black y Scholes.

Objective: An experiment was carried out to evaluate the productive response of dairy cows to rations with maize straw treated and untreated with urea. Design/methodology/approach: Nine cows were randomly selected from each unit and were assigned in a 3x3 Latin square design, repeated three times. The evaluated treatments were: T1= ad libitum maize straw, treated with 40 g urea/kg DM, in urea solution at 10% and 28 days for reaction under plastic + 1 kg maize/cow/day; T2= ad libitum maize straw, untreated, sprayed with a urea solution to add 26 g urea/kg DM at feeding + 1 kg maize/cow/day; and, T3= ad libitum untreated maize straw + 760 g soybean meal as a source of crude protein (CP). Results: Crude protein content of maize straw, increased 96% when straw was treated with urea; moreover, the amount of structural carbohydrates decreased. No significant differences were observed for milk yield, live weight and body condition score (P<0.05). Limitations on study/implications: To see if the diet had the sufficient amount of protein is required analysis of milk urea nitrogen. Findings/conclusions: The addition of urea maize straw increases the nutritive quality of the straw, however, it did not improve the productive parameters of the cows

Objective: Evaluate a quinoa (Chenopodium quinoa Willd) cultivar in a semi-hydroponic system, simulating different levels of sulphatic salinity (CaSO4·2H2O a 0, 3 000, 4 000 y 5 000 µS cm-1). Design/methodology/approach: The cultivation of quinoa established in a semi-hydroponic system, simulating different conditions of sulphatic salinity, taking as a source of salinity reactive grade dihydrated calcium sulphate (CaSO4 · 2H2O), this salinity source is obtained to simulate the conditions of the evaporitic basin of Río Verde-Matehuala, where a saline diversity of waters and soils mainly calcium sulphate is formed. The reactions were 0, 3,000, 4,000 and 5,000 µS cm-1, being that null in salts, the treatment control. Results: The seed yield per plant in sulfate salts treatments ??were for 3,000 µS cm-1 with 30.65 g/p, following the treatments of 4,000 µS cm-1 with 23.31 g/p and 5,000 µS cm-1 with 19.13 g/p; on the other hand, the control resulted in the highest value in yield with 43.41 g/p. Limitations on study/implications: It is important to develop more studies under biotic and abiotic conditions that occur in other regions and test another type of salinity such as hydrochloric. Findings/conclusions: Under the conditions in which the study will be affected, it is possible to grow quinoa in sulphate soils, but with the restrictions imposed by the effect of the decrease in osmotic potential damaged by salts.

Objective: To analyze the effect of the spatial variability of precipitation on the initialgrowth of red cedar (Cedrella odorata L.) in Soconusco, Chiapas, Mexico.Design / methodology / approach: The plantations were established in June 2010 inSuchiate, Tapachula and Tuxtla Chico, Chiapas; with a density of 1,111 trees ha -1planted and spaced 3.0 mx 3.0 m. Every six months (210-2014) tree height (h; m) anddiameter at chest height (DBH; cm) were measured).Results: The average annual height of the trees was correlated; with the accumulatedannual precipitation (Pp; mm), and a simple linear regression equation (R2= 0.94) wasdetermined, which predicts that the growth of the red cedar was 0.09 m for every 100mm of precipitation observed in the different localities. Likewise, its initial growth wasadjusted with a high level of confidence (P?0.001) to the first phase of the Richardssigmoidal model and, from its first derivative, the annual growth rates were determined:2.58 m year-1, 2.05 year -1 and 1.86 year -1 m for the towns of Tapachula, Tuxtla Chicoand Suchiate, respectively.Study limitations / implications: The first phase of the Richards model is onlyapplicable for the initial growth of red cedar and, beyond four years of age, it presentserrors. 2Conclusions: The first phase of Richards' sigmoidal model under the conditionsstudied, predicts with high confidence the initial growth of red cedar for the conditions ofSoconusco, Chiapas.

Objective: to describe the role of the GDF9, BMP15 and BMPR-IB genes on ovulation rate and prolificacy in sheep.Design/methodology/approach: A search and analysis of scientific information related to fecundity genes in sheep was carried out from the Web of Science and Scopus databases.Results: in the fecundity genes, it is included the Growth and Differentiation Factor 9 (GDF9), Bone Morphogenic Protein 15 (BMP15) and Bone Morphogenic Protein Receptor type 1B (BMPR1B), which belong to the Transforming Growth Family factor type ß (TGFß). In most of the mutations found in the coding regions of these genes, heterozygous sheep show an increase in ovulation rate and prolificacy; on the contrary, homozygous sheep are infertile. However, some breeds of sheep with a double mutation or homozygous copies have high ovulation and prolificacy rates.Implications: these genetic variants found in the fecundity genes related to the ovulation rate and prolificacy in the sheep, represent a great utility in the implementation of genetic improvement programs, aimed to improve the reproductive efficiency and profitability of the flocks.Conclusions: these fecundity genes participate in the proliferation, growth and differentiation of theca and granulose cells, favor steroidogenesis in granulosa cells and are fundamental in folliculogenesis at the ovarian level. Heterozygousgenotypes have an increase in ovulatory rate and prolificacy, but homozygous sheep are infertile. However, in somebreeds, homozygous or double mutation genotypes are fertile and have high ovulation and prolificity rates.

Objective: Identify and select primavera plus trees (Roseodendron donell-smithiiMiranda syn Tabebuia donell-smithii Rose) and roble (Tabebeuia rosea Bertol) inSoconusco, Chiapas, Mexico.Design/methodology/approach: Methods were applied to qualify morphometricmarkers such as height, normal diameter, total height and free stem height as mainindicators. With selection intensities to identify future genetic gains, 155 candidate treesand 18 plus trees from Tabebuia donnell-smithii and 140 candidate trees and 16 plustrees from T. rosea were identified.Results: The 34 plus trees showed superior characteristics in quality and volume, sothey were grouped in List A, which is the population that is recommended for immediateuse as Forest Germplasm Producing Units of known origin and provenance. Thesetrees are part of the base population for the improvement program in the Soconusco region (Chiapas, Mexico). The 295 candidate trees maintain at least one superiorcharacter (volume or quality) can be considered in the improvement population, beinglocated in List B.Limitations on study/implications: This work allows defining the commercialpopulation for immediate use and the base population for improvement. Candidateindividuals with potential to be incorporated into future controlled crossing programswere also identified. The procedure allows generating records of the population massand accreditation of the plus tree phenotype.Findings/conclusions: This work allows defining the commercial population forimmediate use and the base population for improvement. Candidate individuals withpotential to be incorporated into future controlled crossing programs were alsoidentified. The procedure allows generating records of the population mass andaccreditation of the plus tree phenotype.

Objective: to evaluate the effect of foliar applications of micronutrients on the quality oftomato fruits (Solanum lycopersicum L.) produced in aquaponics.Design/methodology/approach: the treatments were ACU, aquaponics; ACUFF1equated more foliar fertilization 1 (in mg L-1) with 12.50 Fe, 5.83 Mn, 1.17 Zn, 1.08 B,0.47 Cu, 0.43 Mo and ACUFF2, equated more foliar fertilization 2 (in mg L-1) 25.0 Fe,11.67 Mn, 2.33 Zn, 2.17 B, 0.93 Cu and 0.87 Mo and conventional hydroponics, HID,with the Steiner nutrient solution. To evaluate total soluble solids (SST), titratable acidity(AT), SST / AT ratio, electrical conductivity (EC), pH and lycopene content, ripe fruits(completely red) were used. The experiment was conducted under a completelyrandomized design with four repetitions. An analysis of variance was performed usingthe GLM procedure and the compared of means by Tukey (P ? 0.05) with the SAS 9.3program.Results: foliar applications in aquaponics did not affect SST, AT, SST / AT ratio andlycopene concentration but there was a slight difference in tomato juice pH, the AT, pH,SST / AT ratio and lycopene in aquaponics treatments showed no significant differencesand only SST decreased 22.2% in ACU, 26.6% in ACUFF1 and 31.7% in ACUFF2compared to HID. 2Limitations of the study/implications: the attributes of fruit quality in aquaponicssystems are not affected by the application of nutrients via foliar, which indicates thatthis practice is not necessary under the conditions in which the experiment wasdeveloped.Findings/Conclusions: in aquaponics, foliar applications of micronutrients did notpositively influence the chemical quality attributes of tomato fruits.

ABSTRAC Objective. Arbuscular mycorrhizal inoculation with Glomus spp Zac- 19 (G. claroides, G. diaphanum, and G. albidum) application on Citrus volkameriana Tan & Pasq plants was evaluated to assess growth in nursery conditions without fertilizer application. Methodology. The evaluated treatments were inoculation with 2, 4, 6, 8, and 10 g of inoculum, plus a control treatment without inoculation, in a randomized complete block experimental design with three replicates. The study variables were plant height, stem diameter, number of leaves, leaf area, dry weight, and mycorrhizal colonization. Results A significant statistical response (p?0.01) to inoculation was observed, with a greater growth of mycorrhized plants. Mycorrhizal inoculation was considered appropriate for all levels of inoculation. The outstanding treatment corresponded to the inoculation with 10 g of inoculum which produced plants with 110.16 cm height; 38.56 leaves per plant; 1.13 cm stem diameter; 35.95 g dry root weight; 76.88 g dry weight of the aerial part of the plant; 225.03 cm2 of leaf area per plant, and 88.87% of mycorrhizal colonization in the last sampling. Conclusions The application of 10 g of the Glomus spp Zac-19 arbuscular mycorrhizal consortium per plant to the Citrus volkameriana root promoted the production of more vigorous plants for grafting, without the application of chemical fertilizer.