INIFAP Instituto Nacional de Investigaciones Forestales Agricolas y Pecuarias
Recent publications
The objective of this study was to evaluate the application of hot water treatment to tomato fruits (Solanum lycopersicum cv. TA234) genetically modified with silencing of the TomloxB gene. Unmodified and genetically modified tomato fruits were immersed in water at 40°C for 10, 20 and 30 seconds. Subsequently, fruits were stored at 25°C for 18 days. Physiology was assessed and electrolyte leakage, lipoxygenase and polygalacturonase activities were monitored. Treatment applied to the genetically modified tomatoes at 40°C for 30 seconds, resulted in slower ripening, decreased metabolic activity and maintained the attributes in optimal conditions for longer time, increased the postharvest life of the genetically modified tomatoes until 18 days. Lipoxygenase and polygalacturonase activities were partially inhibited.
Background Guava fruit softening is a crucial process during ripening and this process involves a number of enzymes that modifies the cell wall. Two of the enzymes that regulate this process are (a) the β-1, 4-endoglucanase 17 (BEG) which hydrolyze β-1, 4 bonds from cellulose and hemicellulose, and (b) β-galactosidase (BGA) that hydrolyzes pectin chains. Bioinformatics and expression analysis information on these genes is limited in guava fruit. Results A fragment of a β-1, 4-endoglucanase 17 ( PgE17 ), and another of a β-galactosidase ( PgGa1 ) were identified. These sequences have a similarity of more than 85% with those reported in the NCBI database. In the guava genome, one homologous sequence was found for PgE17 in Chr 4 and two homologous to PgGa1 : one in Chr 3 and the other one in Chr 6. Putative protein PgE17 contains part of the glyco_hydro_9 domain. Putative protein PgGa1 has a part of the glyco_hydro_35 domain. Phylogenetic analysis of PgE17 and PgGa1 revealed that both are highly conserved inside the Myrtaceae family. In silico expression analysis showed that both PgE17 and PgGa1 work in a coordinated way with other cell wall modifier enzymes. Expression of these genes was found in all the guava samples analyzed. However, the highest expression was found in the fruit in the breaking and ripe states. Conclusions A β-1, 4-endoglucanase 17, and β-galactosidase 1 sequences were identified. PgE17 and PgGa1 are expressed in all the plant tissues, and fruit ripening states. Although, the highest expression was on breaker and ripe states.
Background Volcanic eruptions have large effects on forest ecosystems and create new substrates, triggering primary succession processes. The Paricutín volcano, born in central-western Mexico, erupted between 1943 and 1952. After the cessation of the eruptive activity, plant colonization began on the lava flows and tephra deposits, including the conifer species that dominate the surrounding mature forests. This study aims to reconstruct the history of the establishment of conifer trees on the substrates created by the Paricutín eruption. Methods 16 sampling plots were established along three transects with northern, southern, and south-western aspects, located every 250 m from the preserved forest to the volcanic cone. Increment cores from 400 conifer trees were extracted and their age was determined by cross-dating annual tree rings. The order of the species colonization and the tree establishment, abundance, and dominance patterns were characterized. Also, the influence of the distance from the mature forests and the inter-annual climatic conditions on the temporal tree establishment pattern was evaluated. Results Eight pine and one fir species have been established since 1970, only 18 years after the end of the eruptive period. However, tree establishment increased by 12.9% annually after 1995, with the youngest tree in our sample getting established in 2015. We did not find a well-defined temporal and spatial pattern of species arrival, which suggests that colonization occurred randomly, although the four pine species that were established early became the most abundant and dominant. Tree establishment was not influenced by the distance from the mature forest, and wet inter-annual conditions did not enhance pulses of tree recruitment, exhibiting a continuous tree establishment pattern. Conclusions Conifer species have shown a great capacity for colonizing volcanic substrates created by the Paricutín eruption, which suggests that tropical montane conifers can regenerate rapidly under high-magnitude disturbances. These findings support the use of these forest species for ecological restoration.
Aggregate stability is a commonly used indicator of soil health because improvements in aggregate stability are related to reduced erodibility and improved soil–water dynamics. During the past 80 to 90 years, numerous methods have been developed to assess aggregate stability. Limited comparisons among the methods have resulted in varied magnitudes of response to soil health management practices and varied influences of inherent soil properties and climate. It is not clear whether selection of a specific method creates any advantage to the investigator. This study assessed four commonly used methods of measuring aggregate stability using data collected as part of the North American Project to Evaluate Soil Health Measurements. The methods included water stable aggregates using the Cornell Rainfall Simulator (WSACASH), wet sieved water stable aggregates (WSAARS), slaking captured and adapted from SLAKES smart-phone image recognition software (STAB10), and the mean weight diameter of water stable aggregates (MWD). Influence of climate and inherent soil properties at the continental scale were analyzed in addition to method responses to rotation diversity, cash crop count, residue management, organic nutrient amendments, cover crops, and tillage. The four methods were moderately correlated with each other. All methods were sensitive to differences in climate and inherent soil properties between sites, although to different degrees. None measured significant effects from rotation diversity or crop count, but all methods detected significant increases in aggregate stability resulting from reduced tillage. Significant increases or positive trends were observed for all methods in relation to cover cropping, increased residue retention, and organic amendments, except for STAB10, which expressed a slightly negative response to organic amendments. Considering these results, no single method was clearly superior and all four are viable options for measuring aggregate stability. Therefore, secondary considerations (e.g., cost, method availability, increased sensitivity to a specific management practice, or minimal within-treatment variability) driven by the needs of the investigator, should determine the most suitable method.
Background The use of plant growth-promoting microorganisms represents a sustainable way to increase agricultural yields and plant health. Thus, the identification and tracking of these microorganisms are determinants for validating their positive effects on crops. Pangenomes allow the identification of singletons that can be used to design specific primers for the detection of the studied strains. Objective This study aimed to establish a strategy based on the use of whole-genome sequencing and pangenomes for designing and validating primer sets for detecting Bacillus cabrialesii TE3T, Priestia megaterium TRQ8, and Bacillus paralicheniformis TRQ65, a promising beneficial bacterial consortium for wheat. Methods and ResultsThe identification of singletons of TE3T, TRQ8, and TRQ65 was performed by pangenomes using the Kbase platform and subsequently analyzed using BLAST®. The identified DNA regions were used for primer design in AlleleID version 7. Primers were validated by multiplex PCR using pure template DNA from each studied strain, combinations of two or three DNA from these strains, and DNA from agricultural soil samples enriched (and not) with the bacterial consortium. Here, we report the first design of primers capable of detecting and identifying the beneficial strains TE3T, TRQ8, and TRQ65.Conclusions The use of pangenomes allowed the distinction of unique sequences that enables the design of primers for specific identification of the studied bacterial strains. This strategy can be widely used for the design of primer sets to detect other strains of interest for combating biopiracy, and commercial protection of biological products, among other applications.
The objective of this study was to describe the runs of homozygosity (ROH) detected in the Mexican Holstein population and to associate them with milk, fat and protein yields, and conformation final score. After imputation and genomic quality control, 4,227 genotyped animals with 100,806 SNPs markers each were used. ROH with a minimum length of 1 Mb and a minimum of 10 SNPs were included in the analysis. One heterozygous SNP marker and five missing genotypes per ROH were allowed. A total of 425,098 ROH were found in the studied population (71.83 ± 10.73 ROH per animal), with an average length and coverage of 4.80 ± 0.77 Mb, and 276.89 Mb, respectively. The average chromosome length covered by ROH was 10.40 ± 3.70 Mb. ROH between 1 and 2 Mb were the most frequent in the population (51.33%) while those between 14 and 16 Mb were the least frequent (1.20%). Long chromosomes showed a larger number of ROH. Chromosomes 10 and 20, had a greater percentage of their length covered by ROH because they presented a largest number of long ROH (>8 Mb). From the total ROH, 17 were detected in 1,847 animals and distributed among different chromosomes, and were associated with milk, fat and protein yield and percentage, and conformation final score. Of the ROH with effects on production traits, the majority were found with a length between 1 and 4 Mb. These results show evidence of genomic regions preserved by genetic selection and associated with the improvement of the productivity and functionality of dairy cattle.
Thirty accessions of cotton (Gossypium) in the INIFAP genebank in the Iguala Experimental Field were analyzed for resistance to eriophyid mites. Vegetative structures such as leaves and petioles and reproductive structures such as the bract calyx with galls were collected from cotton plants. Galls were cut into cross section to locate mites; taxonomic keys were used to identify the mites. Damage to accessions of cotton was evaluated on a scale of six classes. Damage by eriophyid mites was analyzed with PROC RANK, subjecting it to analysis of variance with PROC GLM, and mean comparison by Tukey (P = 0.05) using statistical software SAS® 9.2. Eriophyidae was reported associated with formation of galls in cotton. Severity of damage was 0 to 85%, but cotton accessions TOA-06, FZ-06, GOS-16, GOS-34, TOA-09, TOA-02, GOS-17, TOA-04, and TOA-05 were resistant. More studies of biology and ecology and molecular analysis are needed to better understand and develop management strategies against mites in cotton.
Agave lechuguilla Torr., of the family Agavaceae, is distributed from southwestern United States to southern Mexico and is one of the most representative species of arid and semiarid regions. Its fiber is extracted for multiple purposes. The objective of this study was to generate a robust model to predict dry fiber yield ( Dfw ) rapidly, simply, and inexpensively. We used a power model in its linear form and bioclimatic areas as dummy variables. Training, generation (80%) and validation (20%) of the model was performed using machine learning with the package ‘ caret’ of R. Using canonical correlation analysis (CCA), we evaluated the relationship of Dwf to bioclimatic variables. The principal components analysis (PCA) generated two bioclimatic zones, each with different A . lechuguilla productivities. We evaluated 499 individuals in four states of Mexico. The crown diameter ( Cd ) of this species adequately predicts its fiber dry weight (R ² = 0.6327; p < 0.05). The intercept (β 0 ), slope [ lnCd (β 1 )], zone [( β 2 )] and interaction [ lnCd :Zona ( β 3 )] of the dummy model was statistically significant (p < 0.05), giving origin to an equation for each bioclimatic zone. The CCA indicates a positive correlation between minimum temperature of the coldest month (Bio 6) and Dwf (r = 0.84 and p < 0.05). In conclusion, because of the decrease in Bio 6 of more than 0.5°C by 2050, the species could be vulnerable to climate change, and A . lechuguilla fiber production could be affected gradually in the coming years.
Turcicum leaf blight (TLB), is a common foliar disease of maize in Mexico that is caused by the fungal pathogen Exserohilum turcicum. The most effective management strategy against TLB is monogenic race-specific resistance. Among the 140 E. turcicum isolates from symptomatic leaves collected from maize fields in Mexico, 100 were obtained from tropical (Veracruz) and temperate areas (Estado de México) between 2010 and 2019, and 40 isolates were obtained from tropical (Sinaloa, Tamaulipas, Veracruz, and Chiapas), subtropical (Nayarit, Jalisco and Guanajuato) and temperate areas (Estado de Mexico, Hidalgo, and Puebla) collected in 2019. All the isolates caused TLB symptoms on the positive control (ht4) showing that they were all pathogenic. Six physiological races of E. turcicum (2, 3, 23, 3N, 23N, and 123N) were identified based on resistant or susceptible responses displayed by five maize differential genotypes (A619Ht1, A619Ht2, A619Ht3, B68HtN, and A619ht4). The most common was race 23 accounting for 68% of the isolates, followed by races 23N, 123N, 3, 2, and 3N at 15%, 8%, 6%, 2%, and 1%, respectively. Race 123N was able to infect the greatest number of maize differential genotypes used in the study. Race 123N was detected in Sinaloa and Estado de México. Race 3 was detected in Nayarit and Jalisco. Race 2 was detected in Jalisco, Estado de México and Veracruz, and race 3N was detected in Tamaulipas. Race 23 was equally dominant in the tropical, subtropical, and temperate regions, while race 123N was more common in the tropical environment and race 23N was more common in the tropical and temperate environments. There was no evidence for shifts in the races between 2010 and 2019.
The objective of the research was to evaluate the e ect of relative humidity (RH) and moisture content (MC) on the incidence of pathogenic fungi on the seeds of Agave lechuguilla, Lippia graveolens, and Nolina cespitifera. Seeds were stored 90 days at 60, 75, 80, and 85% RH, and results were processed with a correlation analysis in the R software using the Spearman test. Higher fungi incidence (FI) in seeds was found from 10 to 20% RH; however, correlation between RH and MC of seeds was positive with r 0.311 and p 2.2 × 10 −16. In general, RH is related to MC, but not to fungi incidence, which is related mainly to MC of seeds. Correlation between RH and FI for each seed species was not signi cant, r 0.026, −0.040, and 0.071 and p 0.687, 0.540, and 0.272 for A. lechuguilla, N. cespitifera, and L. graveolens, respectively. ere was a positive correlation between the MC of seeds with fungi incidence; a negative correlation between the RH and the FI; and a positive correlation between the RH and the MC of seeds. In this type of seeds (orthodox), the MC is probably the most important factor in determining its longevity. e seeds under study can be stored in a 60% to 75% RH. Five fungi genera were found, predominating Aspergillus with ve identi ed species.
Huanglongbing (HLB) is the most important disease in citrus production around the world. Currently, there are not HLB-resistant citrus species or genotypes, however, Persian lime ( Citrus latifolia Tan.) has been reported as the most tolerant citrus species to this disease, but their molecular mechanisms of tolerance has not being characterized yet. In other citrus species, Poncirus trifoliate, it has been suggested that the overexpression of CDR genes is associated to HLB tolerance, therefore, the aim of this work was to identify CDR gene family members in the Persian lime transcriptome and to determine if the HLB infection induces their expression. A Bayesian approach was used to search transcripts with one or two catalytic domains, then, a non-weighted parsimony phylogeny for CDR genes was carried out with the selected transcripts from C latifolia, P. trifoliata and C. sinensis, to identify phylogenetic homologous. The corresponding encoded proteins were obtained from the selected genes, and the similarity among them was estimated using alignments, identity matrix, UPGMA and conserved motifs analysis. Once the ClCDR genes were identified, their expression was determined with the transcriptome data and validated by RT-PCR and qRT-PCR in tissues of asymptomatic and HBL-symptomatic leaves. 146 sequences with one or two catalytic domains, were found, and 7 CDR clades were recovered. Similarity analysis demonstrated that there is a complex relationship among CDR genes and proteins in the species used in the present study. Moreover, the transcriptome and qRT-PCR data showed that none of the ClCDR genes were expressed, neither in healthy nor in HLB-infected Persian lime plants, except for the ClCDR8a gene, which showed high expression. However, no significant differences were found between the ClCDR8a REL values from symptomatic or non-symptomatic leaves. Our results demonstrated the presence of CDR genes in the Persian lime genome, however, they suggest that HLB tolerance is not correlated with the overexpression of this gene family in this species.
In semiarid regions of the western United States, there is heightened interest in tree removal to increase water availability for other uses such as forage growth and groundwater recharge. This study was conducted in central New Mexico to determine the effects of heavy infrequent defoliation of chemically thinned juniper woodland (Juniperus monosperma) on soil moisture. Each of three cattle-grazing exclosures (CD, FG, and KI) was instrumented: 1) beneath trees with a set of three soil moisture probes (0−25, 25−50, and 50−75 cm depth) and one soil temperature probe under live trees (control) and dead trees (herbicide-treated); and 2) between trees with one soil moisture and one soil temperature probe in control and herbicide-treated intercanopy plots. Each plot had three clipped and three unclipped subplots. Mean daily maximum surface soil temperature was highest (17.19°C) in intercanopy, intermediate (16.13°C) under herbicide-treated, and lowest (14.90°C) under control trees. Topsoil moisture (0−25 cm depth) was different among treatment combinations from late July to early September 2006. Thus, the control unclipped combination had the highest topsoil moisture while the herbicide-treated unclipped combination had the lowest topsoil moisture. Comparing other depths, control unclipped plots had higher soil moisture in the middle layer (25−50 cm) and bottom layer (50−75 cm) than at the top from late August to early November 2006. Results imply that clipping on chemically thinned juniper woodlands does not increase soil moisture at any depth, yet macropore flow and water absorption on deep soil layers, underneath live trees, might help to store soil moisture for longer periods in water-limited environments.
Arsenic (As) is a metalloid present in the hydrosphere, lithosphere, and biosphere that at high concentrations causes toxicity in organisms through complex mechanisms. Moreover, the main As sources in ecosystems are both natural and anthropogenic, so it is difficult to avoid this contamination. Certain regions in the world have that characteristics and present high arsenic accumulation in soil, water, and sediments, producing toxicity in crops, livestock, and consequently, in human consumers. In Latin America, this phenomenon occurs in countries such as Chile, Argentina, and Mexico. This review describes the generalities of origin and distribution of arsenic, focusing on toxicity problems in crops that affect Comarca Lagunera in northern Mexico, which represents one of the main As-contaminated regions worldwide. Although some studies have been carried out to analyze and solve this problem, the available information remains scarce, especially about the prevalence of As in the food chain and how to address As contamination. Thus, this review includes biological alternatives of solutions such as bioremediation techniques using mycorrhizas and rhizobacteria such as plant growth-promoting bacteria (PGPB) and nitrogen-fixing bacteria in soils to mitigate the toxicity caused in crops and soils.
Parasitic diseases have a major impact on human and animal health worldwide. Despite the availability of effective anti-parasitic drugs, their excessive and uncontrolled use has promoted the emergence of drug resistance, severely affecting ecosystems and human health. Thus, developing environmentally friendly antiparasitic treatments is urgently needed. Carica papaya has shown promising effects against infectious diseases. C. papaya embryogenic calluses were genetically modified by our research team to insert immunogenic peptides with the goal of developing an oral anti-cysticercosis vaccine. Among these callus cell lines, one labeled as CF-23, which expresses the KETc7 immunogenic peptide, induced the highest protection levels against experimental cysticercosis. In the process of designing a natural antiparasitic product based on C. papaya that simultaneously induced immunity against cysticercosis, both transformed (SF-23) and untransformed (SF-WT) suspension cultures were produced and optimized. Our results showed a better duplication time (td) for SF-23 (6.9 days) than SF-WT (13.02 days); thus, the SF-23 line was selected for scale-up in a 2-L airlift bioreactor, reaching a td of 4.4 days. This is the first time that a transgenic line of C. papaya has been grown in an airlift bioreactor, highlighting its potential for scale-up cultivation in this type of reactor. Considering the previously reported nematocidal activity of C. papaya tissues, their activity against the nematode Haemonchus contortus of aqueous extracts of SF-WT and SF-23 was explored in this study, with promising results. The information herein reported will allow us to continue the cultivation of the transgenic cell suspension line of C. papaya under reproducible conditions, to develop a new anti-parasitic product.
The success of genomic selection (GS) in breeding schemes relies on its ability to provide accurate predictions of unobserved lines at early stages. Multigeneration data provides opportunities to increase the training data size and thus, the likelihood of extracting useful information from ancestors to improve prediction accuracy. The genomic best linear unbiased predictions (GBLUPs) are performed by borrowing information through kinship relationships between individuals. Multigeneration data usually becomes heterogeneous with complex family relationship patterns that are increasingly entangled with each generation. Under these conditions, historical data may not be optimal for model training as the accuracy could be compromised. The sparse selection index (SSI) is a method for training set (TRN) optimization, in which training individuals provide predictions to some but not all predicted subjects. We added an additional trimming process to the original SSI (trimmed SSI) to remove less important training individuals for prediction. Using a large multigeneration (8 yr) wheat (Triticum aestivum L.) grain yield dataset (n = 68,836), we found increases in accuracy as more years are included in the TRN, with improvements of ∼0.05 in the GBLUP accuracy when using 5 yr of historical data relative to when using only 1 yr. The SSI method showed a small gain over the GBLUP accuracy but with an important reduction on the TRN size. These reduced TRNs were formed with a similar number of subjects from each training generation. Our results suggest that the SSI provides a more stable ranking of genotypes than the GBLUP as the TRN becomes larger.
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575 members
Julio Figueroa
Jose L. Gonzalez Barrios
  • Research on Hydrology - Pedology Processes
Samuel Salazar-Garcia
  • Fruit Crops Program, Santiago Ixcuintla Research Station
Karla Rodriguez-Hernandez
  • Dairy Research (Exp. Station La Laguna)
Efrén Díaz
  • National Center for Disciplinary Research in Veterinary Microbiology
Avenida Progreso No. 5, Barrio de Santa Catarina, Delegación Coyoacán, 04010, Mexico City, Mexico