Chapingo Autonomous University

Blueberry (Vaccinium corymbosum) wood diseases represent a significant threat to global production, commonly attributed to fungi belonging to the order Botryosphaeriales; however, emerging fungi causing similar symptoms in the field have recently been detected. The objective of this study was to identify emerging pathogens associated with blueberry wood diseases through phylogenetic, morphological, and pathogenic approaches. Symptomatic samples were collected from 16 commercial fields located in the municipalities of Culiacan, Guasave, Ahome, and El Fuerte in Sinaloa, Mexico. A total of 672 fungal colonies were isolated with the following frequencies: Neopestalotiopsis (48.5%), Alternaria (43.2%), and Curvularia (8.3%). A set of 22 representative isolates was selected for descriptive analyses, considering their distribution across sampling sites and comprising 17 Alternaria, 2 Curvularia, and 3 Neopestalotiopsis isolates. Morpho-phylogenetic analyses differentiated seven species: Alternaria alternata, A. burnsii, A. tomato, A. arborescens, Curvularia plantarum, C. muehlenbeckiae, and Neopestalotiopsis rosae. Pathogenicity assays were carried out by placing mycelial discs onto healthy branches of three-year-old blueberry plants. All tested isolates caused necrotic lesions on inoculated branches, though the degree of aggressiveness differed among them. Alternaria alternata (isolate CCLF533) produced the most severe lesions, whereas A. tomato and Neopestalotiopsis rosae exhibited lower aggressiveness. To our knowledge, this study provides the first global report of Alternaria burnsii, A. tomato, Curvularia plantarum, and C. muehlenbeckiae as causal agents of blueberry wood diseases and represents the first confirmation of A. alternata and A. arborescens as pathogens of blueberry woody tissues, rather than being restricted to fruit or foliar infections. These results emphasize the relevance of studying newly emerging fungal pathogens and reinforce the necessity of establishing integrated disease management programs grounded in epidemiological research.

Invasive alien plants (IAPs) disrupt biodiversity, ecosystem functions, rural livelihoods, and human health/well-being. Hence, the negative impact of Cenchrus setaceus (syn. Pennisetum setaceum) as an invasive weed poses many concerns in terms of environmental and socio-economic impact. The abundance in previous research on invasion ecology, weed biology, and the management of C. setaceus establishes the chance to carry out an in-depth evaluation of this invasive alien species for a cohesive understanding, closely linked to policy development. This systematic review aims to provide a comprehensive evaluation of previous research, identify knowledge gaps, and incorporate recent practical research findings on C. setaceus to elucidate management options. Standard methods were used to collect the literary evidence on multiple thematic aspects linked with its traits and management. Results revealed the substantial negative impacts of C. setaceus on ecosystems, ascribed to multiple physiological, biochemical, and ecological features. Further, a multitude of plant traits such as rapid seed distribution and efficient reproductive strategies imposed serious challenges in the control of C. setaceus. Deployment of integrated control methods for at least three years in depleting seed bank conjunction by planting native grass may help in its confinement. In conclusion, policy measures like strict biosecurity/legal regulations, explicit elucidation of weed biology, early detection and response, ecological modeling, and long-term monitoring with community participation can expand the horizon of C. setaceus control and help achieve its sustainable management.

The objective of this study was to evaluate essential oils (EOs) as an alternative control method for Rhipicephalus microplus and Amblyomma mixtum larvae. The EOs used were obtained by steam distillation from the leaves of cinnamon (Cinnamomum verum), mexican mint (Plectranthus amboinicus), lemongrass (Cymbopogon citratus), peppercorns (Pimenta dioica), and peruvian pepper tree (Schinus molle). To evaluate the acaricidal effect of EOs against the larvae of two tick species, a larval immersion test (LIT) was performed using six concentrations (10 mg/mL, 5 mg/mL, 2.5 mg/mL, 1.87 mg/mL, 1.25 mg/mL, and 0.6 mg/mL), in addition to a negative control group (water + ethanol) and three positive controls (organophosphate, formamidine, and pyrethroid). LIT results were obtained 48 h after exposure. Data were processed using Probit procedure to determine the lethal concentrations at 50% (LC50), 95% (LC95), and 99% (LC99). For R. microplus, 99% mortality was obtained at concentrations as low as 1.4 mg/mL for S. molle, while the highest LC99 was recorded with P. dioica at 23 mg/mL. In the case of A. mixtum, higher concentrations were required to achieve a high mortality rate. EO of P. amboinicus had the lowest acaricidal effect, requiring 26.2 mg/mL to achieve an LC99, while S. molle required a concentration of 6.9 mg/mL to achieve an LC99.

In this study, we adapted a physiologically structured model based on ordinary differential equations, derived from Rossini's general framework, to describe the population dynamics of Eotetranychus kankitus in four peach varieties (Oro Azteca, Diamante Mejorado, Arkansas, and F70) under real field conditions in Tepeyahualco, Puebla, M & eacute;xico. During the 2024 growing season, 19 samples were collected, yielding the mean mites-per-leaf abundance. The thermal functions for development, fecundity, and mortality were fitted using published laboratory data for E. kankitus, whereas five key reproductive parameters that define the thermal fecundity curve (a beta, b beta, k beta), the relative fecundity of mated females (c2), and the transition from mated to unmated females (G1 <- 2) were estimated using Bayesian inference. The estimate was obtained using an affine-invariant ensemble sampler Markov Chain Monte Carlo implemented in the emcee library. The overall results provided a satisfactory representation of population abundance; however, variety-specific calibrations revealed biologically and statistically significant differences in reproductive parameters. In particular, cultivar-specific estimates revealed clear differences in parameters governing reproductive state: Arkansas exhibited higher values of the relative fecundity of mated females (c2) and the transition rate from mated to unmated females (G1 <- 2), whereas consistently lower values were inferred for F70, indicating reduced reproductive output across the season. These findings demonstrate that peach variety is a key determinant of E. kankitus population dynamics and that accounting for varietal differences through cultivar-specific parameter calibration substantially enhances the model's predictive performance. This study constitutes one of the first cultivar-scale calibrations for E. kankitus and establishes a methodological framework that integrates physiological data, field observations and Bayesian inference to support pest forecasting and management in fruit tree systems.

The dynamic changes in the physicochemical, microbiological, and metagenomic profiles of Crema de Chiapas cheese were evaluated across three ripening stages (2, 29, and 58 days). Although the main physicochemical properties -including fat content- remained remarkably stable, salt and protein levels showed noticeable variation throughout ripening. Protein content had the strongest influence on sample differentiation across ripening stages in unsupervised multivariate models, enabling the clustering of microbial diversity according to maturation time. A clear shift in microbial diversity was detected, marked by a reduction in bacterial genera and a concurrent decline in fungal and yeast populations as ripening advanced. The predominant bacterial genera throughout ripening were Streptococcus, Lactobacillus, and Lactococcus. While Streptococcus and Lactobacillus increased over time, Lactococcus exhibited the opposite trend. Metagenomic analysis revealed a decrease in Candida etchellsii and a concomitant increase in Candida tropicalis as ripening progressed. Quantitative PCR (qPCR) confirmed the presence of C. etchellsii at T1 (Ct = 7.22) and C. tropicalis at T3 (Ct = 9.84). The presence of three additional bacterial genera-Chryseobacterium, Aeromonas, and Enterobacter-identified by next-generation sequencing (NGS), was also assessed by qPCR. Chryseobacterium was detected at T2 (Ct = 3.26), whereas Aeromonas and Enterobacter were absent across all stages. Collectively, these findings suggest that potentially pathogenic microorganisms were not present at biologically relevant levels.