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

Water deficit is a major limiting factor for crop productivity and significantly impacts the viability and vigor of soybean seeds (Glycine max). This study aimed to evaluate the effects of water deficit on the germination-emergence phenological stage in soybean genotypes classified as either drought-tolerant or sensitive during flowering. The experiment followed a completely randomized design with four replications. A factorial scheme of 10 × 6 was used, comprising 10 soybean genotypes (genotype 1, genotype 2, genotype 3, genotype 4, genotype 5, genotype 6, genotype 7, genotype 8, genotype 9, and genotype 10) and six osmotic potentials (-0.0, -0.2, -0.4, -0.6, -0.8, and -1.0 MPa), achieved using polyethylene glycol 6000 (PEG 6000). The analyzed variables included first germination count and germination percentage (from the germination test), shoot and root length, shoot and root dry mass (from the seedling growth test), and vigor from the cold test. Data were fitted to regression models. The results showed that reducing the osmotic potential with PEG 6000, from -0.2 MPa onwards, negatively affected the germination and vigor of soybean seeds, regardless of whether the genotypes were drought-tolerant or sensitive during flowering. Soybean genotypes displayed varying responses to water deficit during the germination-emergence stage, indicating that drought tolerance during flowering does not necessarily predict their performance under water stress at earlier growth stages.

Starting with the current volume (year 2025), we are implementing some minor changes to the formal aspects of the journal. The changes respond to the need to update some styles commonly used in most journals of the area. For example, the clause “et al.” will now be used in italics. Since the journal was created in 1983, the use of normal letters for the clause was adopted. Inertia has maintained this style since then; this, despite the fact that our guidelines for authors order the use of italics for terms written in Latin, or another language with no equivalent in Spanish yet. Another formal adjustment concerns the use of the p for statistical probability. We used to use it as a capital P, and now it will be a lowercase p. Among other adjustments, the definition of the style for writing bibliographical references is still pending. From the beginning, Bioagro used a modification of the Harvard system, the most widely used in science at that time. However, we must migrate to one of the pre-established systems among those existing in the current reference manager softwares, and in this way make it easier for authors to write manuscripts, and standardize the style in all articles. We hope to define the new style to be used soon.

Aspergillus sp. and Penicillium sp. are fungi widely studied for their biotechnological applications. In the agricultural field, their benefical characteristics make them an attractive alternative source for biological disease control. Cacti, such as the giant cardon (Pachycereus pringlei) group a great diversity of this type of desert species that have greater metabolic action, due to their resistance to extreme environments. However, there are few studies on this subject. The objective of this research was to isolate, identify and evaluate the antagonism of Penicillium sp. and Aspergillus sp. isolated from the rhizosphere of giant cardon against phytopathogenic root fungi. Forty soil samples were collected from the rhizosphere of cardon, at 30 cm depth in four sites in the municipality of La Paz, Baja California Sur. The population and diversity were calculated and the purified isolates were identified macroscopically and microscopically. The pathogenicity of the isolates was determined by inoculation in tomato fruits. While the antagonism was evaluated through dual culture, with Fusarium oxysporum, Fusarium solani and Rhizoctonia solani. The results were recorded in all the agroecosystems evaluated a higher population of Penicillium sp. than Aspergillus sp. (5 versus 2 isolates). The most abundant species was P. digitatum. The antagonism showed significant differences (p≤0.05) between isolates of the same genus (different species), presenting up to 70% mycelial inhibition. While in the pathogenicity test, two Penicillium isolates and one Aspergillus isolate showed a greater effect than the rest. This information confirms the capacity of Aspergillus sp. and Penicillium sp. in the control of plant pathogens.

The use of endophytic bacteria of the genus Bacillus as biocontrol agents against Moniliophthora roreri is presented as an environmentally effective option in agriculture. The objective was to evaluate the effect of the application of endophytic B. amyloliquefaciens against the causal agent of moniliasis in cocoa. The experiment was conducted in a 14-year-old cocoa plantation, under a 3 x 3 m frame, in a randomized complete block design, with three treatments (frequency of application: 15, 30 and 45 days) and five replications. During the 90 days of development at a biweekly frequency, incidence and external severity were evaluated on the pod. At harvest time, the pods were opened and the percentage of internal severity was determined. Also, endophytic colonization was determined. It was found that six applications of spore suspension had a biocontrol effect on M. roreri, with average incidence between 1.0 and 4.1 %, external severity between 1.8 and 8.5 %, internal severity between 5.9-6.3 % and endophytic colonization between 7.3-7.5 x 108CFU g-1 of plant tissue. The application of the bacteria, at a fortnightly frequency, had a biocontrol effect on M. roreri, with average incidence values between 1.0 and 4.1 %, external severity between 1.8 and 5.0 %, internal severity between 5.9-6.3 % and endophytic colonization between 7.3-7.5 x 108 CFU g-1 of plant tissue. The biweekly application frequency demonstrated a biocontrol effect on M. roreri due to its high capacity for endophytic colonization, without differences with the control, presenting itself as a biological alternative to reduce the effects caused by the moniliasis in cocoa agroecosystems. 

Coffee leaf rust, caused by Hemileia vastratix Berk. and Br. (Hv), is economically the most important disease of this crop worldwide. More than 50 physiological races have been identified, which indicate its genetic diversity, due to either by genetic mutations or by the presence of transposable genes. In this study, a total of 21 isolates of the fungus were characterized using RAPD and REMAP markers between the two techniques, including race XXXIX, two pathotypes Hv01ve and Hv02ve, which were previously identified for Venezuela, and three control isolates (Rz II, Rz XXXIII and Hv05) from Brazil. Isolates were collected in the states of Lara and Táchira.  After DNA extraction, RAPD was performed using twenty six primers of the OPA, OPB, OPC, OPD, OPE, OPF, OPG, OPH, OPK, OPL, OPM, OPN, OPO  and OPP series; and REMAP with five combinations LTR/ISSR (48F/D1C, 48R/D1C, 48R/T1C, 81F/D1C and 81F/T1C), using standard protocols. Statistical analysis was realized using the Infogen program. Results showed that 92.11% of RAPD and 96.55% of REMAP amplified bands were polymorphic and its information (PIC) varied from 0.15 to 0.32, which suggests a high genetic diversity among the Hv isolates. In addition, in both markers three groups were formed, discriminated by geographic distribution and altitude.

Cherry tomato has been increasing its market demand in Brazil, primarily due to desirable consumption characteristics. Studies aimed at optimizing the agroecological cultivation of cherry tomato remain limited and inconclusive. The aim of this work was to evaluate the effect of biofertilizers on the plant development and production of cherry tomatoes in the cerrado of Roraima. The experiment was carried out in a greenhouse at the Agricultural Sciences Center of the Federal University of Roraima, Boa Vista. For the experiment, a randomized block design was used, arranged in a 2 x 4 factorial scheme (2 types of biofertilizers and 4 doses), with four replications. Two types of organic fertilizer were evaluated, using ordinary biofertilizer (BC: 50 % cattle manure + 50 % water) and enriched biofertilizer (BE: 15 % cattle manure + 15 % poultry manure + 10 % carbonized rice husk + 10 % gravel powder + 50 % water), with the following doses (0; 800; 1600 and 2400 mL·plant-1). The analysis revealed a significant effect of the dose of biofertilizer, type of biofertilizer and their interaction, promoting increasing responses in the dry mass of the aerial part, dry mass of the roots, number of fruits produced and the equatorial diameter of the fruits. However, the plants treated with enriched biofertilizer showed higher values when compared to the plants treated with ordinary biofertilizer. Increasing doses of biofertilizers promoted higher yields, regardless of treatment. The use of biofertilizers in increasing doses promotes the vegetative and productive development of cherry tomatoes.

Moniliasis in cocoa is considered the main phytosanitary factor limiting production in the producing areas of Latin America. Evaluate the application of mixed agricultural alternatives in the agroecological management of this disease in cultivation. The study was conducted in the Gavilanes Panamericana sector, municipality Obispo Ramos de Lora of the state of Mérida, Venezuela, on plants 3 years old; using a completely random design, establishing seven treatments, 1: Trichoderma harzianum, 2: Maintenance and sanitary pruning; 3: Humato, 4: T. harzianum + Maintenance and sanitary pruning; 5: Humato + Maintenance and sanitary pruning; 6: Humato + T. harzianum and T7: Absolute control in batches of five cocoa trees and three repetitions, for a total of 105 experimental units. The pathometric indices were evaluated: incidence of disease (IE), external severity index (ISE) and internal in fruit (ISI) and for the records of effect on yields was determined the weight of the almond in dross (PAB).IE was lower in all alternative treatments than in the control, with a remarkable use of maintenance and sanitary pruning at an index of 22.87 %. Humato applications showed a significant reduction in the ISE of 1,86 to 0,80 degrees compared with the increase in the same time range to 3,60 in control. Use of Trichoderma harzianum reduced the ISI of the disease in the fruit from grade 5 (from 61 to 80% damage) to 2 (from 1 to 20% damage). Finally, the applications of pruning and the use of T. harzianum were the treatments that showed the greatest increase in BAP from 130.38 to 338.67 g and 148.33 to 343.33 g. The use of agricultural alternatives reduced the disease in fruit plants and increased the weight of the almond, which turned out to be an integral management strategy.

 Understanding the molecular mechanisms of sugar accumulation in the taproot of sugar beet (Beta vulgaris L.) is essential for enhancing sugar production. In this study, we analysed growth parameters and gene expression profiles of taproots collected at 50 (S1), 90 (S2), 160 (S3), and 330 (S4) days after sowing (DAS). Growth analysis revealed that the length, width, and weight of the taproots increased over time, with a particularly rapid weight gain observed between 50 and 160 DAS. Sugar content increased sharply from 50 to 90 DAS, gradually rose until 160 DAS, and then tended to decrease up to 330 DAS. Differential expression analysis identified 4,560, 4,764, and 4,781 differentially expressed genes (DEGs) in comparisons between S1:S2, S1:S3 and S1:S4, respectively. Among these, 3,255 DEGs were common across all comparisons, with 1,345 genes upregulated and 1,909 genes downregulated. Focusing on sugar metabolism, we identified 48 DEGs related to sucrose metabolism enzymes and sugar transport proteins. Cluster analysis divided these DEGs into two groups based on their expression patterns: Class I genes including those encoding sucrose synthase, sucrose transporter proteins, fructokinase, and hexokinase were downregulated compared to S1, while Class II genes including sucrose transporter proteins, sucrose-phosphate synthase, fructokinase, and hexokinase were upregulated. These findings contribute to understanding of the gene expression associated with sugar accumulation during sugar beet taproot development and provide valuable insights for future genetic improvement aimed at increasing sugar content in sugar beet crops.

Huanglongbing (HLB) is a devastating disease of citrus characterized by yellow spots on the foliage, leaf chlorosis, small and deformed fruits, premature leaf drop, and tree decline which is caused by Candidatus Liberibacter asiaticus. The state of Tamaulipas in Mexico is one of the main producers of Citrus in the country. Given the arrival of HLB in the region, this work focuses on analyzing the individual rhizosphere from symptomatic and asymptomatic orange, lemon, and grapefruit plants cultivated in an orchard in the state. Microbial profiles were analyzed by using a metagenomic approach and bioinformatic tools. The results show that microbial diversity is different between symptomatic and asymptomatic lemon plants. Particularly, the asymptomatic grapefruit plants show the lowest microbial diversity. In general, all Citrus species show differences in their bacterial population structure, identifying groups related to beneficial bacteria, and differences in microbial diversity, according to the presence of HLB symptoms.

Grain sorghum is planted annually in Mexico on 1 427 202 ha; 55,12 % of this area corresponds to the State of Tamaulipas, mainly under rainfall conditions, with yields of 2 284 kg ha-1. The objective of this research was to identify sorghum genotypes that present high grain yield and stability, comparing the stability parameters of Eberhart and Russell and the GGE biplot model, to define the model that best describes the G x A interaction. This research was carried out with five sorghum genotypes in 14 test environments: seven irrigated and seven only with pre-sowing irrigation in Rio Bravo, Tamaulipas, during 2023. Grain yield kg·ha-1 was analyzed using the Eberhart and Russell stability parameters and the GGE biplot model. The results show that when the Eberhart and Russell model was used, the P83G19 hybrid was identified as a consistent, stable genotype, with a grain yield 1.23 % higher than the general average, and the ADV-G3247 hybrid and the RB-Williams variety were identified as consistent genotypes, which respond better in good environments, with grain yields 7.31 and 0.4 % higher than the general average, respectively. When the GGE biplot model was used, the P83G19 hybrid exhibited stability and good grain yield. The two stability analysis models consistently identified stable and high-yielding genotypes, determining the accuracy of both methods and their usefulness in understanding the Genotype x Environment (G x E) interaction to identify genotypes with broad or specific adaptation.