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

The evaluation of vegetable germplasm variation is important to classify and identify the desirable characteristics for improvement and conservation of crops. The objective of the study was to analyze the morpho-agronomic diversity of cassava accessions in the Las Montañas region, Veracruz, Mexico. The morphogenetic diversity of 11 cassava accessions was determined with the Shannon (H’) index and the Jaccard similarity coefficient (J’) from 30 qualitative characters. An analysis of main components (ACP) and cluster was applied to 15 quantitative characters. The characters with significant variation were the shape of the central lobe of the sheet, orientation of the petiole, color of the epidermis and shape of the plant. The H 'index oscillated between 0.13 and 1 (x̄= 0.43) indicating a low diversity due to similarity (J' from 43 to 100%; x̄= 69%) between accessions, which were classified into 3 groups according to the analysis of Cluster, coinciding with the ACP that explained 87% of the variation. The study indicates the existence of sufficient genetic information provided by the variability of four morpho-agronomic characters, which is attributed to the diversity of lineages that are adapted to the geographical origin of the accessions evaluated.

In the gene pool of wild tomato populations, natural defenses represent an alternative to generate resistant or tolerant varieties to insects. The objective of this study was to evaluate the incidence of Bemisia tabaci and its relationship with antioxidant compounds in tomato germplasm. Two wild species (Solanum habrochaites and S. pimpinellifolium) were examined; eight Mexican natives and the Rio Grande variety (control). In a non-choice trial, the number of nymphs (Ni) and eggs (Hu) was recorded. The content of phenolic compounds (Cf) and the antioxidant activity DPPH (Aaox) were analyzed by spectrophotometry in plants with incidence (CI) and without incidence (SI) of B. tabaci. There were differences between genotypes in Ni + Hu (p < 0.004) and Cf (p < 0.0001). Differences from SI to CI in Cf (p < 0.0001) and in Aaox (p <0.0001) indicate variations in the modulation of antioxidant compounds between genotypes. The correlations of Ni + Hu with Aaox (-0.44**), Cf with Aaox (0.31**) and Ni + Hu with Cf (-0.23), indicate the participation of antioxidant molecules to different degrees. S. habrochaites with the lowest insect incidence and the native Mexican 21207 with the highest Cf content demonstrate potential in plant breeding programs.  

Ichneumonidae is a family that contains important species for biological pest control. In Nayarit, the studies about the diversity and distribution of Ichneumonidae are poorly known in crops of economic importance for the state, such is the avocado. The objective was to know the subfamilies, genera and/or species of Ichneumonidae distributed in plots of different avocado cultivars in the state. Collections were made during January and April 2021 in two municipalities of Nayarit. The entomological net collection method was used. One genus and four species are registered to the knowledge of this family.

In this study, the effect of solid-state fermentation on a defatted Jatropha curcas meal with and without hydrothermal treatment was evaluated using Saccharomyces cerevisiae (6 × 109 CFU/g) and incubated for 24, 72 and 144 h at 36°C. The content of antinutrients was determined by spectrophotometric methods, the content of phorbol esters was evaluated by high-resolution thin layer chromatography, and the nutritional composition was evaluated by proximal analysis. A two-factor design (type of treatment and fermentation time) was used with response variables of the content of phytates, saponins, phorbol esters and nutritional content. The flour that had the characteristics of our interest was the one that was only fermented for 144 h without hydrothermal treatment because it presented a significant reduction of 74% of phytates, 51% of saponins, in addition to the fact that no phorbol esters were detected. The protein and ash content (44.50 and 12.52%, respectively) did not have significant changes. Additionally, a decrease in fat and fiber content was observed from 15.84 to 13.21% and from 9.29 to 5.54%, respectively. Therefore, this flour is recommended to be implemented in a balanced diet for Nile tilapia.

The objective was to identify subclinical mastitis using California mastitis test (CMT) and to isolate and identify phenotypes of Staphylococcus spp., strains derived from goat milk. A study was conducted from February 2023 to May 2023, in 21 different farms in Santa Cruz de Juventino Rosas, Guanajuato. The detection of subclinical mastitis was carried out using the CMT analyzed the milk of 430 goats; Positive CMT milk samples were tightly closed, refrigerated at 4°C, and transported to the laboratory, where they were cultivated on agar medium for 24 or 48 h. Antimicrobial sensitivity of Staphylococcus strains was evaluated using the disk diffusion technique. 27.6% of the goats were positive for CMT. Several pathogens can cause mastitis, but Staphylococcus spp. are the most frequently diagnosed causal microorganisms of intramammary infections in goats, in bacteriological detection, Staphylococcus haemolyticus, S. hyicus, S. chromogenes, S. caprae and S. epidermidis were identified. Some Staphylococcus isolates were sensitive to cefotaxima. In conclusion, therefore, the control of mastitis in goats should take into account the optimal milking routine and milking hygiene.

With the purpose of studying the effect of climate through the global wet bulb index (WBGTi), on the seminal quality of Quarter Horse stallions, in a farm in Tuxtlas, Veracruz, in a tropical environment, meteorological variables, ambient temperature and relative humidity, were evaluated for nine years (2013-2021), to determine the daily and monthly average HTGBH and relate it to the macroscopic (volume) and microscopic characteristics (percentage of mobility, vitality, normal sperm and concentration spermatic) from semen obtained from five stallions. There was an environment of thermal comfort from December to February (íTGBH≤26.99), within the thermo-neutral zone of the horses; while from April to July it was thermally stressful (íTGBH=32.99 to 36.80); with a significant difference (p≤0.05) in the percentage of mobility (75.21±2.58 vs 62.79±2.51), vitality (80.50±2.03 vs 71.10±3.42) and normal sperm (68.80±1.55 vs 58.02±2.0), being lower during the hottest period. Sperm volume and concentration were not influenced by the increase in the index but were influenced by seasonality. It is concluded that the increase in heat, measured in terms of íTGBH, had a negative effect on the seminal quality of stallions.

The changes in temperature and precipitation regimes caused by climate change have resulted in the displacement of production areas, both coffee and cocoa, to areas with more favorable conditions for their development. The objective of this study was to evaluate the adaptation of cocoa cultivation at different altitude levels in the Upper Yaque del Norte River Basin, located in the central mountain range of the Dominican Republic, for which its survival and initial development in areas where coffee cultivation has been degraded. To meet the stated objectives, different experimental units were established with two types of cocoa plants, graft and hybrid, in three altitudinal ranges of the basin. In each sample unit, aerial growth, health condition and survival of the plants were evaluated, under a completely randomized design. It is concluded that altitude significantly affected the morphological variables total height, neck diameter, productivity index, as well as survival. In general, the aerial growth of the plant decreased as the altitude above sea level increased, regardless of the type of plant used.

The growth of forest plantations (FP) is dynamic, and it is essential to simulate it with tools that facilitate its management. The study was carried out in FP of Pinus leiophylla of the Indigenous Community of Patamban, Michoacán; 42 sampling sites of 400 m2. were established, the dominant height (Ad) and age of 126 trees were obtained. 11 statistical models were fitted to obtain the Ad; The best model was chosen through the values of the adjusted coefficient of determination (R2adj), root mean square error (RCME), Akaike and Bayesian information criterion (AIC and BIC), bias and average relative range (RRP). To generate the anamorphic SI curves, the asymptote parameter was cleared, and the expression was substituted into the integral equation at a base age of 20 years. The turn of Ad was six years at the intersection point of ICA=IMA, where the FP reached a mean annual increase in Ad of 0.86, 1.21, and 1.56 m for the site indices of 10, 14, and 18 m. The Schumacher model allowed us to describe with greater precision the Ad and reliability the SI classes that adequately describes the sample variation in PF of P. leiophylla.

The coexistence of pregnancy and diabetes mellitus results in major malformations incompatible with life, developmental delay, pregnancy loss, or maternal-fetal death. Treatment with glycine reverses the harmful effects of glucose, in male patients and in animal models; as well as the metabolic and biochemical changes caused by diabetes mellitus/hyperglycemia. However, the effect on diabetic pregnancy has not been investigated, so this study was designed. Pregnant rats were randomly assigned to four groups: control, glycine, diabetic, diabetic + glycine. The subjects were euthanized on day 19 of gestation, fetuses were obtained, as well as liver and maternal blood serum. The fetuses were evaluated for malformations, both gross and internal. Maternal serum was processed to determine glucose, cholesterol and triglycerides; In the fetal liver, the activities of scavenging enzymes and lipoperoxidation were determined. The administration of glycine improves fetal development and biochemical-clinical parameters, but in healthy rats, it does not affect these parameters or fetal development. Excess glucose can cause oxidative stress, which is partially reversed by glycine, which enhances fetal development impaired by hyperglycemia.

The raicilla is a distillate, product of the ferment of juices of Agave maximiliana pineapples, which are still found in wild form in the Western Sierras of the State of Jalisco. Therefore, the objective of this work consisted in the identification of the different ecotypes of Agave maximilina existing in the western highlands of the state of Jalisco, with their differentiation in the production of biomass and reducing sugars. The work was carried out in 2020 in Mascota, Jalisco, 195 km west of Guadalajara. Semi-structured interviews were conducted with producers and root masters and the ethnotaxa of the different ecotypes were collected. Biomass production was quantified by collecting four specimens per year of growth from 2 to 8 years per ecotype, weighing each pineapple where each weight represented a repetition of the ecotype. The quantification of reducing sugars was carried out by the DNS technique. Seven variants were identified, in which the biomass between them showed no statistical difference in the first 3 years. At 8 years the average yield ranged from 14.25 kg to 47.87 kg depending on the ecotype. Reducing sugar production ranged from 32% to 83%.  A. maximiliana shows high intraspecific genetic variability reflected in pineapple size and weight between and within ecotypes, as well as in the production of total reducing sugars. In the present study, the best ecotypes according to their biomass and total reducing sugar production were the ecotypes named Típica and Costillona.