Genomic regions, candidate genes, and pleiotropic variants associated with physiological and anatomical indicators of heat stress response in lactating sows.

BACKGROUND: Heat stress (HS) poses significant threats to the sustainability of livestock production. Genetically improving heat tolerance could enhance animal welfare and minimize production losses during HS events. Measuring phenotypic indicators of HS response and understanding their genetic background are crucial steps to optimize breeding schemes for improved climatic resilience. The identification of genomic regions and candidate genes influencing the traits of interest, including variants with pleiotropic effects, enables the refinement of genotyping panels used to perform genomic prediction of breeding values and contributes to unraveling the biological mechanisms influencing heat stress response. Therefore, the main objectives of this study were to identify genomic regions, candidate genes, and potential pleiotropic variants significantly associated with indicators of HS response in lactating sows using imputed whole-genome sequence (WGS) data. Phenotypic records for 18 traits and genomic information from 1,645 lactating sows were available for the study. The genotypes from the PorcineSNP50K panel containing 50,703 single nucleotide polymorphisms (SNPs) were imputed to WGS and after quality control, 1,622 animals and 7,065,922 SNPs were included in the analyses. RESULTS: A total of 1,388 unique SNPs located on sixteen chromosomes were found to be associated with 11 traits. Twenty gene ontology terms and 11 biological pathways were shown to be associated with variability in ear skin temperature, shoulder skin temperature, rump skin temperature, tail skin temperature, respiration rate, panting score, vaginal temperature automatically measured every 10 min, vaginal temperature measured at 0800 h, hair density score, body condition score, and ear area. Seven, five, six, two, seven, 15, and 14 genes with potential pleiotropic effects were identified for indicators of skin temperature, vaginal temperature, animal temperature, respiration rate, thermoregulatory traits, anatomical traits, and all traits, respectively. CONCLUSIONS: Physiological and anatomical indicators of HS response in lactating sows are heritable but highly polygenic. The candidate genes found are associated with important gene ontology terms and biological pathways related to heat shock protein activities, immune response, and cellular oxidative stress. Many of the candidate genes with pleiotropic effects are involved in catalytic activities to reduce cell damage from oxidative stress and cellular mechanisms related to immune response.

Nutritional Characterization of Chilean Landraces of Common Bean.

Common bean (Phaseolus vulgaris L.) is the primary grain legume cultivated worldwide for direct human consumption due to the high nutritional value of its seeds and pods. The high protein content of common beans highlights it as the most promising source of plant-based protein for the food industry. Additionally, landraces of common bean have great variability in nutritional traits, which is necessary to increase the nutritional quality of elite varieties. Therefore, the main objective of this study was to nutritionally characterize 23 Chilean landraces and 5 commercial varieties of common bean to identify genotypes with high nutritional value that are promising for the food industry and for genetic improvement programs. The landrace Phv23 ('Palo') was the most outstanding with high concentrations of minerals such as P (7.53 g/kg), K (19.8 g/kg), Mg (2.43 g/kg), Zn (52.67 mg/kg), and Cu (13.67 mg/kg); essential amino acids (364.8 mg/g protein); and total proteins (30.35 g/100 g seed). Additionally, the landraces Phv9 ('Cimarrón'), Phv17 ('Juanita'), Phv3 ('Araucano'), Phv8 ('Cabrita/Señorita'), and Phv4 ('Arroz') had a high protein content. The landrace Phv24 ('Peumo') stood out for its phenolic compounds (TPC = 218.1 mg GA/100 g seed) and antioxidant activity (ORAC = 22,167.9 µmol eq trolox/100 g extract), but it has moderate to low mineral and protein concentrations. In general, the concentration of nutritional compounds in some Chilean landraces was significantly different from the commercial varieties, highlighting their high nutritional value and their potential use for the food industry and for genetic improvement purposes.

Investigating the impact of non-additive genetic effects in the estimation of variance components and genomic predictions for heat tolerance and performance traits in crossbred and purebred pig populations.

BACKGROUND: Non-additive genetic effects are often ignored in livestock genetic evaluations. However, fitting them in the models could improve the accuracy of genomic breeding values. Furthermore, non-additive genetic effects contribute to heterosis, which could be optimized through mating designs. Traits related to fitness and adaptation, such as heat tolerance, tend to be more influenced by non-additive genetic effects. In this context, the primary objectives of this study were to estimate variance components and assess the predictive performance of genomic prediction of breeding values based on alternative models and two independent datasets, including performance records from a purebred pig population and heat tolerance indicators recorded in crossbred lactating sows. RESULTS: Including non-additive genetic effects when modelling performance traits in purebred pigs had no effect on the residual variance estimates for most of the traits, but lower additive genetic variances were observed, especially when additive-by-additive epistasis was included in the models. Furthermore, including non-additive genetic effects did not improve the prediction accuracy of genomic breeding values, but there was animal re-ranking across the models. For the heat tolerance indicators recorded in a crossbred population, most traits had small non-additive genetic variance with large standard error estimates. Nevertheless, panting score and hair density presented substantial additive-by-additive epistatic variance. Panting score had an epistatic variance estimate of 0.1379, which accounted for 82.22% of the total genetic variance. For hair density, the epistatic variance estimates ranged from 0.1745 to 0.1845, which represent 64.95-69.59% of the total genetic variance. CONCLUSIONS: Including non-additive genetic effects in the models did not improve the accuracy of genomic breeding values for performance traits in purebred pigs, but there was substantial re-ranking of selection candidates depending on the model fitted. Except for panting score and hair density, low non-additive genetic variance estimates were observed for heat tolerance indicators in crossbred pigs.

The impact of pig breed on stress levels and meat quality: a study on mangalita purebred and Duroc x Landrace crossbred pigs in Romania / [O impacto da raça suína nos níveis de estresse e na qualidade da carne: um estudo em porcos Mangalita puro-sangue e Duroc x Landrace cruzados na Romênia]

ABSTRACT This study aimed to investigate the impact of pig breed on stress levels and meat quality in two commercial pig farms in the north-eastern part of Romania. One farm raised 52 Mangalita pure-bred pigs and the other 82 Duroc x Landrace crossbred pigs. Serum cortisol, a biomarker of stress, and serum glucose were measured before and after slaughtering, while meat pH was measured at 45 minutes and 24 hours post-mortem. Results showed that the Duroc x Landrace crossbred pigs had higher serum cortisol and glucose values before and after slaughtering compared to the Mangalita purebred pigs. The meat pH values of the two breeds were similar, with the pH45 and pH24 values being 6.67 and 5.48 for Duroc x Landrace crossbred and 6.53 and 5.52 for Mangalita purebred, respectively. These results suggest that pig breed can have an impact on stress levels and meat quality, with Duroc x Landrace crossbred pigs showing higher stress levels and meat quality being not affected by the breed of pig. Further research is needed to confirm these findings and to understand the underlying mechanisms.

RESUMO Este estudo teve como objetivo investigar o impacto da raça suína nos níveis de estresse e na qualidade da carne em duas fazendas comerciais de suínos, no nordeste da Romênia. Uma fazenda criou 52 suínos puros Mangalita, e a outra 82 suínos mestiços Duroc x Landrace. O cortisol sérico, um biomarcador de estresse e a glicose sérica foram medidos antes e após o abate, enquanto o pH da carne foi medido aos 45 minutos e 24 horas post mortem. Os resultados mostraram que os suínos mestiços Duroc x Landrace apresentaram valores séricos de cortisol e de glicose mais elevados, antes e após o abate, em comparação com os suínos puros Mangalita. Os valores de pH da carne das duas raças foram semelhantes, sendo os valores de pH45 e pH24 de 6,67 e 5,48 para o mestiço Duroc x Landrace e de 6,53 e 5,52 para o puro sangue Mangalita, respectivamente. Esses resultados sugerem que a raça suína pode ter um impacto nos níveis de estresse e na qualidade da carne, com os porcos mestiços Duroc x Landrace apresentando níveis mais altos de estresse e a qualidade da carne não sendo afetada pela raça do porco. Mais pesquisas são necessárias para confirmar esses achados e entender os mecanismos subjacentes.

Characterisation of landrace 'criollo' maize silage from the highlands of Mexico in terms of starch content.

Maize silage is appreciated for dairy cows due to its high energy content. Mexico is a centre of origin for maize and small-scale dairy farmers use landrace 'criollo' maize silages to feed their herds. However, the characteristics of landrace 'criollo' maize silages in terms of starch content, which defines their nutritional value in terms of energy, are not known. The objective was to characterise criollo maize silages in terms of starch content. Seventy-seven silage samples from 2011 to 2015 were analysed for contents of dry matter (DM), organic matter (OM), neutral detergent fibre (NDF), acid detergent fibre (ADF), crude protein (CP), in vitro dry matter digestibility (IVDMD), and starch content. A factor analysis using principal component analysis as an extraction method was undertaken, and a hierarchical cluster analysis performed. Five factors affected the starch content of silages and five maize silage clusters identified. There was a positive association between IVDMD and metabolisable energy and between crude protein and acid detergent fibre; moreover, a positive relation was found between dry matter and maize starch contents. Significant differences were found (P < 0.001) for the contents of IVDMD, ME, ashes, OM, DM, and starch. The DM content of group 1 silage did not show any significant differences from other groups, except with group 2 silage, which had the lowest contents of DM and starch. Therefore, group 1 and 5 silage had the highest DM and starch contents, while group 3 silage had the highest IVDMD values and ME contents; finally, group 4 had the highest ash contents. Starch content in criollo maize silages was higher that reports for other maize races and is influenced by climate conditions and dry matter content.

Mobilization of seed storage proteins is crucial to high vigor in common bean seeds / Mobilização das proteínas de reserva é crucial para o alto vigor em sementes de feijão

Seed germination is a complex process controlled by many factors, in which physical and biochemical mechanisms are involved and the mobilization of reserves is crucial for this process to occur. Although, seed reserve mobilization is usually thought to be a post-germination process, seed reserve proteins mobilization occurs during germination. This study quantified seed proteins of bean genotypes during different hydration times, in order to understand the process of protein mobilization and whether there is relationship of this biochemical component with seed vigor. This study was conducted using seeds with different levels of vigor, genotypes with highest (13, 42, 55 and 81) and lowest (07, 23, 44, 50, IPR-88-Uirapurú and Iapar 81) physiological quality. High vigor genotypes showed greater efficiency in hydrolysis and mobilization of protein component, because they presented low globulins content in cotyledons at radicle protrusion in relation to low vigor genotypes (07, 23 and 50). The protein alpha-amylase inhibitor, observed in all genotypes, is involved with the longer time needed for radicle protrusion, according to the band intensity difference in genotypes 07, 44 and Iapar 81.

A germinação de sementes é um processo complexo controlado por muitos fatores, nos quais mecanismos físicos e bioquímicos estão envolvidos e a mobilização de reservas é decisiva para que esse processo ocorra. Embora a mobilização de reservas de sementes seja considerada um processo pós-germinativo, a mobilização das proteínas de reserva de sementes ocorre durante a germinação. Este estudo teve como objetivo quantificar as proteínas de sementes de genótipos de feijão durante os diferentes tempos de hidratação, a fim de compreender o processo de mobilização proteica e se há relação desse componente bioquímico com o vigor das sementes. Este estudo foi realizado utilizando sementes com diferentes níveis de vigor, genótipos com maior (13, 42, 55 e 81) e menor (07, 23, 44, 50, IPR-88-Uirapurú e Iapar 81) qualidade fisiológica. Os genótipos de alto vigor apresentaram maior eficiência na hidrólise e mobilização do componente proteico, pois apresentaram baixo teor de globulinas nos cotilédones na protrusão radicular em relação aos genótipos de baixo vigor (07, 23 e 50). A proteína inibidora da alfa-amilase, observada em todos os genótipos, está envolvida com o maior tempo necessário para a protrusão da radícula, de acordo com a diferença de intensidade da banda nos genótipos 07, 44 e Iapar 81.

Characteristics of faecal bacterial flora and volatile fatty acids in Min pig, Landrace pig, and Yorkshire pig

BACKGROUND In order to study the influence of long-term growth process and evolution environment on intestinal bacteria of different breeds, the intestinal bacteria and volatile fatty acids among the faeces of Min, Landrace and Yorkshire pigs were analysed by Illumina high-throughput sequencing of the 16S-rDNA and gas chromatography. RESULTS The shared core microbiota of Landrace, Yorkshire and Min pig were 1273, accounting for 69.56% of total abundance of organisms. The proportion of Firmicutes in Min pig faeces (57.89%) was significantly higher than that in Landrace and Yorkshire pig faeces (47.01% and 46.40%, respectively) (P < 0.05), but that of Bacteroidetes was exactly opposite. Moreover, Min pig presented more highly efficient membrane transport, environmental adaptation, carbohydrate transport, and metabolism than Yorkshire pig (P < 0.05). The acetic acid/total volatile fatty acid ratio in Min pig was significantly higher than that in Landrace pig (P < 0.05), and the isobutyric acid/ total volatile fatty acid ratio in Min pig was significantly larger than that in Yorkshire pig (P < 0.05). Furthermore, the content of branched chain volatile fatty acids in Min pig was significantly higher than that in Yorkshire pig (P < 0.05). CONCLUSION This study demonstrated that Min pig, as an excellent breed in the cold area of China, possessed special intestinal floral structure compared to the imported pigs in order to satisfy their phys iological and metabolic demands, which may influence their characteristics such as resistance to cold, diseases, and crude feeding, and the ability to deposit intramuscular fat.

The influence of maize genotype on the rhizosphere eukaryotic community.

The microbiota colonizing the rhizosphere contributes to plant growth, productivity, carbon sequestration and phytoremediation. Several studies address plant-associated bacteria; however, few studies analyze the effect of plant genotype on the eukaryotic community. Here, we analyzed the eukaryotic composition of maize rhizosphere from three different plant landraces and one inbred line grown in the same soil (common garden approach). This experimental design, coupled with 18S rDNA gene amplicon sequencing, allowed us to test the influence of maize and its genotype on the rhizosphere's eukaryotic community. We found that plant growth modified the eukaryotic community in soil, as diversity comparisons between maize rhizosphere and unplanted soil revealed significantly different eukaryotic composition. Various genera of nematodes and fungi, predominantly bacterial feeding nematodes and mycorrhizal fungi among other taxa, were increased in the rhizosphere samples. We also observed that maize genotype differentially shaped the relative abundance of the following fungal families in the rhizosphere: Acaulosporaceae, Aspergillaceae, Chaetomiaceae, Claroideoglomeraceae, Corticiaceae, Mortierellaceae, Trichocomaceae and Trichomeriaceae. Thus, plant genotype has a selective influence on establishing fungal communities in the rhizosphere. This study emphasizes the importance of an integrated consideration of plant genetics for future agricultural applications of microbes to crops.

Influence of Wounding and Temperature on Resistance of Maize Landraces From Mexico to Aflatoxin Contamination.

Maize is a staple for billions across the globe. However, in tropical and sub-tropical regions, maize is frequently contaminated with aflatoxins by Aspergillus section Flavi fungi. There is an ongoing search for sources of aflatoxin resistance in maize to reduce continuous exposures of human populations to those dangerous mycotoxins. Large variability in susceptibility to aflatoxin contamination exists within maize germplasm. In Mexico, several maize landrace (MLR) accessions possess superior resistance to both Aspergillus infection and aflatoxin contamination but their mechanisms of resistance have not been reported. Influences of kernel integrity on resistance of four resistant and four susceptible MLR accessions were evaluated in laboratory assays. Wounds significantly (P < 0.05) increased susceptibility to aflatoxin contamination even when kernel viability was unaffected. Treatments supporting greater A. flavus reproduction did not (P > 0.05) proportionally support higher aflatoxin accumulation suggesting differential influences by some resistance factors between sporulation and aflatoxin biosynthesis. Physical barriers (i.e., wax and cuticle) prevented both aflatoxin accumulation and A. flavus sporulation in a highly resistant MLR accession. In addition, influence of temperature on aflatoxin contamination was evaluated in both viable and non-viable kernels of a resistant and a susceptible MLR accession, and a commercial hybrid. Both temperature and living embryo status influenced (P < 0.05) resistance to both aflatoxin accumulation and A. flavus sporulation. Lower sporulation on MLR accessions suggests their utilization would result in reduced speed of propagation and associated epidemic increases in disease both in the field and throughout storage. Results from the current study should encourage researchers across the globe to exploit the large potential that MLRs offer to breed for aflatoxin resistant maize. Furthermore, the studies provide support to the importance of resistance based on the living host and maintaining living status to reducing episodes of post-harvest contamination.

Morphological Diversity and Genetic Relationships in Pulque Production Agaves in Tlaxcala, Mexico, by Means of Unsupervised Learning and Gene Sequencing Analysis.

Pulque is one of the oldest fermented beverages, with its origins dating back to pre-Hispanic Mexico. Recently, public consumption has increased. However, the majority of Agave plantations for pulque production have disappeared or been abandoned in recent decades. To create strategies for the conservation and production of pulque agaves, it is necessary to first determine their taxonomic identities and to better understand their genetic and morphological diversity. Despite the historical importance of pulque in Mexico, little attention has been placed on the study of Agave plants used for its production. Therefore, we analyzed the morphological diversity of vegetative characters of nine landraces of two Agave species (A. salmiana and A. mapisaga) which are widely cultivated for pulque production in Tlaxcala, Mexico. The analysis of morphological characters showed that the landraces largely clustered based on classic taxonomic relationships. One cluster of landraces associated with Agave mapisaga var. mapisaga and another with A. salmiana subsp. salmiana, but with the exception of A. salmiana subsp. salmiana "Ayoteco", which is more closely related with A. mapisaga var. mapisaga. Additionally, we analyzed the genetic relationships between 14 landraces and wild individuals using molecular markers (trnL and ITS). The identified genetic variants or haplotypes and genetic pools mainly corresponded with the species. In the case of "Ayoteco", incongruence between markers was observed. Low selection intensity, genetic flow events, and the plasticity of morphological traits may explain the high number of landraces without clear differences in their morphological diversity (vegetative characters) or genetic pools. The use of reproductive traits and massive sequencing might be useful for identifying possible morphological and genetic changes in the Agave landraces used for pulque production.

Transcriptional differentiation of UV-B protectant genes in maize landraces spanning an elevational gradient in Chiapas, Mexico.

Globally, farmers cultivate and maintain crop landraces (i.e., traditional varieties). Landraces contain unique diversity shaped in part by natural and human-mediated selection and are an indispensable resource for farmers. Since environmental conditions change with elevation, crop landraces grown along elevational gradients have provided ideal locations to explore patterns of local adaptation. To further probe traits underlying this differentiation, transcriptome signatures can help provide a foundation for understanding the ways in which functional genetic diversity may be shaped by environment. In this study, we returned to an elevational gradient in Chiapas, Mexico, to assess transcriptional differentiation of genes underlying UV-B protection in locally adapted maize landraces from multiple elevations. We collected and planted landraces from three elevational zones (lowland, approximately 600 m; midland, approximately 1,550 m; highland approximately 2,100 m) in a common garden at 1,531 m. Using RNA-seq data derived from leaf tissue, we performed differential expression analysis between maize from these distinct elevations. Highland and lowland landraces displayed differential expression in phenylpropanoid and flavonoid biosynthesis genes involved in the production of UV-B protectants and did so at a rate greater than expected based on observed background transcriptional differentiation across the genome. These findings provide evidence for the differentiation of suites of genes involved in complex ecologically relevant pathways. Thus, while neutral evolutionary processes may have played a role in the observed patterns of differentiation, UV-B may have also acted as a selective pressure to differentiate maize landraces in the region. Studies of the distribution of functional crop genetic diversity across variable landscapes can aid us in understanding the response of diversity to abiotic/biotic change and, ultimately, may facilitate its conservation and utilization.

Compositional Variation in Trans-Ferulic, p-coumaric, and Diferulic Acids Levels Among Kernels of Modern and Traditional Maize (Zea mays L.) Hybrids.

Maize is one of the most heterogenous cereals worldwide in terms of yield, physical characteristics, and biochemical composition due to its natural diversity. Nowadays the use of maize hybrids is extensive, while the use of landraces is mostly local. Both have become an important genetic resource useful to identify or generate varieties with desirable characteristics to overcome challenges of agronomic performance, nutritional quality, and functionality. In terms of functionality, one of the most studied families of compounds are phenolic acids. These compounds have been associated with the improvement of human health because of their antioxidant capacity. To evaluate the diversity of phenolic compounds in maize, two collections, the Nested Association Mapping (NAM) founders and 24 landraces, were crossed with B73. Phenolic compounds were extracted and quantified by HPLC-PDA. Soluble and cell wall phenolic acids were identified and significant differences between and within the NAM and Landrace collections were assessed. Soluble p-coumaric acid quantification of B73 × NAM hybrids presented high variation as the range went from 14.45 to 132.34 µg/ g dw. In the case of B73 × Landrace hybrids, wide variation was also found, ranging 25.77-120.80 µg/g dw. For trans-ferulic acid, significant variation was found in both hybrid groups: B73 × NAM presented an average of 157.44 µg/g dw (61.02-411.13 µg/g dw) whereas the B73 × Landrace hybrids average was 138.02 µg/g dw (49.32-476.28 µg/g dw). In cell wall p-coumaric acid, a range from 30.93 to 83.69 µg/g dw and 45.06 to 94.98 µg/g dw was found for landrace and NAM hybrids, respectively. For cell wall trans-ferulic acid, a range from 1,641.47 to 2,737.38 µg/g dw and 826.07 to 2,536.40 µg/g dw was observed for landrace and NAM hybrids, respectively. Significant differences between hybrid groups were found in p-coumaric acid, for both soluble and cell wall-bounded. Therefore, maize hybrids produced by conventional techniques using both modern and traditional varieties showed a high diversity in terms of phenolic compounds, denoting the role of these compounds in the maize ability to endure different environment conditions. This study provides a platform of comparison through the unveiling of maize phenolic compounds for future breeding efforts.

Postural changes, nursing behavior, and production performance of two breeds of sows in enriched environment

This study was performed to compare changes in posture, nursing behavior, and production performance of two breeds of sows. The posture, postural changes, nursing behavior, and production performance of hybrid Damin (Large White × Min pig, n = 32) and Landrace × Large White (n = 32) sows were observed by video recording for 72 h after farrowing and from 07:00 to 09:00 h and 13:00 to 15:00 h within any successive two-day period of each week from the two to five weeks postpartum. The production performances were compared between the two breeds. Except standing at days 1 to 3 postpartum and sitting at day 2 postpartum, there were significant differences in postures between the two breeds of sows. The frequency of ventral-to-lateral recumbency at day 1 and weeks 4 and 5 postpartum and sitting-tolying at days 1 and 3 and weeks 4 and 5 postpartum was significantly lower for the Damin than for Landrace × Large White sows. The frequency of standing-to-lying in the first 72 h postpartum was significantly higher for the Damin than for Landrace × Large White sows. At days 2 and 3 postpartum, piglet loss was significantly lower for the Damin than for Landrace × Large White sows. The duration of parturition and farrowing interval were significantly longer for the Landrace × Large White than for Damin sows. The number of live piglets was higher for the Damin than for Landrace × Large White sows. The birth weight of litters and weaning weight of piglets were lower for Damin than for Landrace × Large White piglets. These data suggest that the Damin sows showed stronger maternal instincts through their behaviors and postural changes compared with the Landrace × Large White sows.(AU)

Landrace maize varieties differ from conventional and genetically modified hybrid maize in response to inoculation with arbuscular mycorrhizal fungi.

Land area planted with genetically modified (GM) crops has grown rapidly, and Brazil has the second largest area with those plants. There is, however, limited information on the possible effects of that technology on non-target organisms, especially root symbionts, such as arbuscular mycorrhizal fungi (AMF). We evaluated AMF symbiosis development in five maize genotypes: one landrace, two conventional hybrids (DKB 240 and Formula), and two GM hybrids (DKB 240-VT Pro and Formula TL). We evaluated symbiosis response in two separate experiments: one in autumn and the other in summer. Plants were inoculated with Rhizophagus clarus (Rc) and Gigaspora margarita (Gm) and compared to plants without inoculation. We evaluated root colonization, spore number, and plant biomass and phosphorous accumulation 30 and 60 days after inoculation. There were no consistent effects of GM crops, but AMF species and maize genotype affected symbiosis development. Formula genotype (isoline and GM) had a negative response to inoculation, with a decrease of around 30% in biomass and P concentration in Rc-inoculated plants. The maize landrace had a positive response, with increases of 17% and 14% in the same variables. DKB genotype (isoline and GM) showed negative, positive, and neutral effects. The results show that plant genetic identity is a determinant factor in symbiosis performance, suggesting that plants selected in low P availability can make better use of mycorrhizal symbiosis. Given the role that AMF play in different ecosystem processes, use of landrace maize may contribute to agrobiodiversity conservation.

Genome-wide genotyping of a novel Mexican Chile Pepper collection illuminates the history of landrace differentiation after Capsicum annuum L. domestication.

Studies of genetic diversity among phenotypically distinct crop landraces improve our understanding of fruit evolution and genome structure under domestication. Chile peppers (Capsicum spp. L.) are economically valuable and culturally important species, and extensive phenotypic variation among landraces exists in southern Mexico, a center of C. annuum diversity. We collected 103 chile pepper seed accessions from 22 named landraces across 27 locations in southern Mexico. We genotyped these accessions with genotyping by sequencing (GBS), yielding 32,623 filtered single-nucleotide polymorphisms. Afterward, we genotyped 32 additional C. annuum accessions from a global collection for comparison to the Mexican collection. Within the Mexican collection, genetic assignment analyses showed clear genetic differentiation between landraces and clarified the unique nature of the Tusta landrace. Further clustering analyses indicated that the largest fresh-use Chile de Agua and dry-use Costeño landraces were part of separate clades, indicating that these two landraces likely represent distinct populations. The global accessions showed considerable admixture and limited clustering, which may be due to the collapse of use-type divisions outside of Central America. The separation of the Mexican landraces in part by fruit morphology related to use highlights the relevance of this use-type morphological diversity for plant breeders and the utility of fruit development variation for evolutionary biologists.

Strategies to control inbreeding in a pig breeding program: a simulation study / Estratégias para controle de endogamia em um programa de melhoramento genético de suínos: um estudo de simulação

The objective of this study was to evaluate, through data simulation, the impact of restrictions on the maximum number of full- and half-sibs selected for males and females on the level of inbreeding and genetic gain of the herd. Data came from real populations A and B, composed of Pietrain and Landrace breed pigs, respectively. To generate the simulated populations, a Fortran-language simulator was developed using the (co)variances of the breeding values and the productive and reproductive rates obtained from populations A and B. Two data files were created. The first contained the pedigree of the previous 10 years, with 21,906 and 251,343 animals in populations A and B, respectively. The second included breeding values for age to reach 110 Kg body weight, backfat thickness, and feed conversion, for both populations; longissimus dorsi muscle depth, for population A only; and number of live piglets at the 5th day of life per farrowing, for population B only. Three scenarios were simulated with ten generations by varying the restrictions on the number of full- and half-sibs selected for males and females, with 30 replicates per generation and scenario. Regardless of the mating strategy used in a closed production unit, there is an increase in inbreeding levels. Inbreeding increases are larger in populations of smaller effective size. Restrictions on the number of full- and half-sibs selected are effective in reducing increments in inbreeding. Restriction to a maximum of two full-sibs and three half-sibs for males and three full sisters for females provided the highest genetic gains.(AU)

O objetivo deste estudo foi avaliar, por meio de simulação de dados, o impacto das restrições no número máximo de irmãos completos e meios-irmãos selecionados para machos e fêmeas no nível de endogamia e ganho genético do rebanho. Os dados originais são provenientes das populações reais A e B, compostas por suínos da raça Pietrain e Landrace, respectivamente. Para gerar as populações simuladas, foi desenvolvido um simulador em linguagem Fortran utilizando as (co)variâncias dos valores genéticos e as taxas produtivas e reprodutivas obtidas das populações A e B. Dois arquivos de dados foram criados. O primeiro continha o pedigree dos 10 anos anteriores, com 21.906 e 251.343 animais nas populações A e B, respectivamente. O segundo incluiu os valores genéticos para idade para atingir 110 Kg de peso vivo, espessura de toucinho e conversão alimentar, para ambas as populações; profundidade do músculo longissimus dorsi, apenas para a população A; e número de leitões vivos no 5º dia de vida por parto, apenas para a população B. Três cenários foram simulados com dez gerações, variando as restrições quanto ao número de irmãos completos e meios-irmãos selecionados para machos e fêmeas, com 30 repetições por geração e cenário. Independentemente da estratégia de acasalamento utilizada em um núcleo de produção fechada, há aumento nos níveis de endogamia. Aumentos de endogamia são maiores em populações de menor tamanho efetivo. Restrições ao número de irmãos completos e meios-irmãos selecionados são eficazes na redução de incrementos na endogamia. A restrição de no máximo dois irmãos completos, três meios-irmãos para machos e três irmãs completas para fêmeas fornece os maiores ganhos genéticos.(AU)

Strategies to control inbreeding in a pig breeding program: a simulation study / Estratégias para controle de endogamia em um programa de melhoramento genético de suínos: um estudo de simulação

ABSTRACT: The objective of this study was to evaluate, through data simulation, the impact of restrictions on the maximum number of full- and half-sibs selected for males and females on the level of inbreeding and genetic gain of the herd. Data came from real populations A and B, composed of Pietrain and Landrace breed pigs, respectively. To generate the simulated populations, a Fortran-language simulator was developed using the (co)variances of the breeding values and the productive and reproductive rates obtained from populations A and B. Two data files were created. The first contained the pedigree of the previous 10 years, with 21,906 and 251,343 animals in populations A and B, respectively. The second included breeding values for age to reach 110 Kg body weight, backfat thickness, and feed conversion, for both populations; longissimus dorsi muscle depth, for population A only; and number of live piglets at the 5th day of life per farrowing, for population B only. Three scenarios were simulated with ten generations by varying the restrictions on the number of full- and half-sibs selected for males and females, with 30 replicates per generation and scenario. Regardless of the mating strategy used in a closed production unit, there is an increase in inbreeding levels. Inbreeding increases are larger in populations of smaller effective size. Restrictions on the number of full- and half-sibs selected are effective in reducing increments in inbreeding. Restriction to a maximum of two full-sibs and three half-sibs for males and three full sisters for females provided the highest genetic gains.

RESUMO: O objetivo deste estudo foi avaliar, por meio de simulação de dados, o impacto das restrições no número máximo de irmãos completos e meios-irmãos selecionados para machos e fêmeas no nível de endogamia e ganho genético do rebanho. Os dados originais são provenientes das populações reais A e B, compostas por suínos da raça Pietrain e Landrace, respectivamente. Para gerar as populações simuladas, foi desenvolvido um simulador em linguagem Fortran utilizando as (co)variâncias dos valores genéticos e as taxas produtivas e reprodutivas obtidas das populações A e B. Dois arquivos de dados foram criados. O primeiro continha o pedigree dos 10 anos anteriores, com 21.906 e 251.343 animais nas populações A e B, respectivamente. O segundo incluiu os valores genéticos para idade para atingir 110 Kg de peso vivo, espessura de toucinho e conversão alimentar, para ambas as populações; profundidade do músculo longissimus dorsi, apenas para a população A; e número de leitões vivos no 5º dia de vida por parto, apenas para a população B. Três cenários foram simulados com dez gerações, variando as restrições quanto ao número de irmãos completos e meios-irmãos selecionados para machos e fêmeas, com 30 repetições por geração e cenário. Independentemente da estratégia de acasalamento utilizada em um núcleo de produção fechada, há aumento nos níveis de endogamia. Aumentos de endogamia são maiores em populações de menor tamanho efetivo. Restrições ao número de irmãos completos e meios-irmãos selecionados são eficazes na redução de incrementos na endogamia. A restrição de no máximo dois irmãos completos, três meios-irmãos para machos e três irmãs completas para fêmeas fornece os maiores ganhos genéticos.

Phenolic Acids Profiles and Cellular Antioxidant Activity in Tortillas Produced from Mexican Maize Landrace Processed by Nixtamalization and Lime Extrusion Cooking.

Phenolic acids profiles, chemical antioxidant activities (ABTS and ORAC), as well as cellular antioxidant activity (CAA) of tortilla of Mexican native maize landraces elaborated from nixtamalization and lime cooking extrusion processes were studied. Both cooking procedures decreased total phenolics, chemicals antioxidant activity when compared to raw grains. Extruded tortillas retained 79.6-83.5%, 74.1-77.6% and 79.8-80.5% of total phenolics, ABTS and ORAC values, respectively, compared to 47.8-49.8%, 41.3-42.3% and 43.7-44.4% assayed in traditional tortillas, respectively. Approximately 72.5-88.2% of ferulic acid in raw grains and their tortillas were in the bound form. Regarding of the CAA initially found in raw grains, the retained percentage for traditional and extruded tortillas ranged from 47.4 to 48.7% and 72.8 to 77.5%, respectively. These results suggest that Mexican maize landrace used in this study could be considered for the elaboration of nixtamalized and extruded food products with nutraceutical potential.

Attraction, Feeding Preference, and Performance of Spodoptera frugiperda Larvae (Lepidoptera: Noctuidae) Reared on Two Varieties of Maize.

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is an economically important pest of maize and other crops in the Americas. Studies suggest that modern varieties of maize lost some of their natural defense mechanisms against herbivores during domestication and agricultural selection. In the present study, we evaluated the attraction, feeding preference (host fidelity and consumption rate), and performance of S. frugiperda larvae reared on hybrid (Pioneer P4063W) and landrace (Tuxpeño) varieties of maize. We also evaluated the damage caused by S. frugiperda to Pioneer and Tuxpeño maize plants in the field. We found that fifth-instar larvae were more attracted to Pioneer plants than to Tuxpeño plants in a Y-tube olfactometer. Additionally, the fall armyworm larvae showed more fidelity to Pioneer leaves than to Tuxpeño leaves. However, the larval consumption rate was similar for both types of maize plants. The life cycle of S. frugiperda was significantly longer when the larvae were reared on Tuxpeño leaves than on Pioneer leaves. In the field, the Pioneer variety was infested with more S. frugiperda larvae than the Tuxpeño variety. Thus, our results provide evidence that modern varieties of maize may have lost some of their defensive traits during selective breeding.

Hydration patterns and physiologic quality of common bean seeds / Padrão de hidratação e qualidade fisiológica de sementes de feijão

This study aimed to investigate the relationship between the hydration pattern of landrace bean genotypes and their physiological quality. The hydration curve of eight landrace (BAFs 07, 13, 23, 42, 44, 50, 55, 81) and two commercial cultivars (IPR-88-Uirapurú and Iapar 81) genotypes was determined from seed moisture. Determination of initial physiological quality was performed by germination and vigor tests (seedling performance and accelerated aging). Characterization of the genotypes, regarding accelerated aging tests, showed that BAFs 13, 42, 55 and 81 had the highest physiological potential, whereas BAFs 07, 23, 44, 50 and the commercial cultivars had lower physiological quality. The hydration curve followed a triphasic pattern with radicle protrusion occurring between 21 and 27 hours after seed hydration. The percentage of reserves translocated to the seedling during formation showed that BAF 42 had the highest conversion efficiency compared to the smaller efficiencies of BAFs 23, 50 and Iapar 81. The seedling length test showed that BAFs 42 and 55 had the most vigorous seedlings, which was driven by the high percentage of reserves translocated to the seedling during formation. BAFs 23, 50 and the cultivar Iapar 81 showed lower reserve translocation, demonstrating that low mobilization potential leads to smaller seedlings. The hydration of bean seeds during germination wa

O trabalho objetivou verificar relação do padrão de hidratação de genótipos crioulos de feijão e a sua qualidade fisiológica. Utilizaram-se oito genótipos crioulos (BAFs 07, 13, 23, 42, 44, 50, 55, 81) e dois comerciais (IPR-88-Uirapurú e Iapar 81) submetidos à determinação da curva de hidratação por meio da umidade das sementes. A determinação da qualidade fisiológica inicial foi realizada por meio do teste de germinação e testes de vigor (desempenho de plântulas e envelhecimento acelerado). A caracterização dos genótipos quanto ao teste de envelhecimento acelerado evidenciou os BAFs 13, 42, 55 e 81 como sendo de maior potencial fisiológico, e os BAFs 07, 23, 44 e 50 e cultivares comerciais, apresentando menor qualidade fisiológica. A curva de hidratação seguiu padrão trifásico com protrusão radicular entre 21 e 27 horas. O percentual de reserva translocada para a formação da plântula demonstrou que o BAF 42 obteve a maior eficiência de conversão comparada às menores, BAFs 23 e 50 e cultivar Iapar 81. Os BAFs 42 e 55 apresentaram plântula mais vigorosa pelo teste de comprimento de plântulas, decorrente do alto percentual de reserva translocada para a formação da plântula. Os BAFs 23 e 50 e a cultivar Iapar 81 apresentaram menor translocação de reservas e demonstraram que este baixo potencial de mobilização culminou com plântulas menores. A hidratação das sementes de feijão dur