Inbred Lines Research Articles

Identification and quantitative trait locus mapping of Tartary buckwheat pre-harvest sprouting.

Tartary buckwheat (Fagopyrum tartaricum) is particularly vulnerable to pre-harvest sprouting (PHS) due to its extended flowering and fruiting cycle, especially during periods of prolonged rainfall. This susceptibility has significant adverse effects on yield, quality and post-harvest processing. In this study, a recombinant inbred lines (RILs) population (XJ-RILs) was developed from a cross between the PHS-susceptible Tartary buckwheat variety 'Xiaomiqiao' (female parent) and the highly PHS-resistant variety 'Jinqiaomai 2' (male parent). Key traits, including germination percentage, germination energy, germination index, field PHS (PHS-F) and simulated PHS (PHS-S), were evaluated, and a quantitative trait locus (QTL) mapping analysis was performed. (i) PHS-S was strongly and significantly correlated with PHS-F. (ii) A total of 11 QTLs associated with seed germination and 14 QTLs related to PHS were identified. Notably, the major QTL cluster qPHS8-1 was consistently detected and mapped within the interval of 8.53-9.65 Mbp on chromosome Ft8. (iii) Genotyping of 221 XJ-RILs across eight chromosomes revealed five residual heterozygous lines carrying a heterozygous interval of qPHS8-1 cluster, with inbred line R56 being particularly suited for the fine mapping of qPHS8-1. The PHS-S test, conducted on entire Tartary buckwheat spikes, is an effective and comprehensive method for assessing PHS resistance in this crop. QTL mapping identified qPHS8-1 as a major locus for PHS resistance, and inbred line R56 offers a promising resource for further fine mapping of this cluster. © 2025 Society of Chemical Industry.

The molecular mechanism by which heat stress during the grain filling period inhibits maize grain filling and reduces yield

High temperatures significantly impair plant growth and development by restricting maize grain filling; however, the molecular mechanisms underlying heat stress remain poorly understood. In this study, 350 maize inbred lines were evaluated under field conditions, leading to the identification of heat-tolerant Zheng58 and heat-sensitive Qi319. The two inbred lines were exposed to controlled conditions of 30°C/20°C (optimal) and 42°C/30°C (heat stress) during the grain filling period. Heat stress significantly reduced thousand-kernel weight and seed setting rates, with Qi319 experiencing more pronounced declines. In contrast, Zheng58 showed superior performance, with a grain filling rate 48% higher and seed setting rate 57% greater than Qi319. Transcriptome analysis showed that heat stress disrupted starch biosynthesis and hormonal homeostasis, notably affecting abscisic acid and auxin pathways. Additionally, photosynthetic and transpiration rates in panicle leaves were reduced due to the downregulation of genes related to light-harvesting complexes, photosystem I subunits, and water transport. These findings highlight the critical roles of starch metabolism, hormonal regulation, and photosynthetic efficiency in heat tolerance, offering valuable insights for developing heat-resilient maize varieties to mitigate yield losses under high-temperature conditions.

Genetic Mapping for Seed Aging Tolerance Under Multiple Environments in Sweet Corn

Seed vigor significantly impacts seed production and storage. Enhancing seed vigor is a pivotal goal in sweet corn breeding, as improved seed sowing quality is crucial for agricultural development, aiding in better resilience against storage adversities and facilitating long-term germplasm preservation. In this study, a recombinant inbred line (RIL) population, including 158 families, was derived from the aging-tolerant line K62 and the aging-sensitive line K107. Utilizing SNP arrays, genotypes were identified, and a genetic linkage map was constructed. Composite interval mapping was employed to detect quantitative trait loci (QTLs) associated with five seed vigor traits, namely the seedling fresh weight (SFW), germination potential (GP), germination rate (GR), germination index (GI), and vigor index (VI), at three days after artificial aging treatment. Upon analysis, a total of 42 QTLs affecting seed vigor indices were identified over two years. Of these, six were linked to SFW, while the GP, GR, GI, and VI each comprised nine QTLs. Nine QTL clusters were identified, with significant contributions (>10%) from Loci02.1, Loci05.2, Loci06.1, and Loci10.1, ranging from 9.50% to 24.20%, 8.89% to 11.54%, 9.16% to 15.55%, and 7.54% to 17.77%, respectively. Candidate genes were explored within QTL cluster regions based on the aging-induced transcriptomic sequencing data of K62 and K107. Through Gene Ontology enrichment, gene annotation, and expression profiling clustering analyses, 12 positive candidate genes linked to seed aging tolerance were identified. This study provides a foundational understanding of the genetic mechanisms of seed aging tolerance and the innovation of an elite germplasm for seed aging tolerance in sweet corn.

Genome-Wide Association Study on Imputed Genotypes of 180 Eurasian Soybean Glycine max Varieties for Oil and Protein Contents in Seeds

Soybean (Glycine max) is a leguminous plant with a broad range of applications, particularly in agriculture and food production, where its seed composition—especially oil and protein content—is highly valued. Improving these traits is a primary focus of soybean breeding programs. In this study, we conducted a genome-wide association study (GWAS) to identify genetic loci linked to oil and protein content in seeds, using imputed genotype data for 180 Eurasian soybean varieties and the novel “genotypic twins” approach. This dataset encompassed 87 Russian and European cultivars and 93 breeding lines from Western Siberia. We identified 11 novel loci significantly associated with oil and protein content in seeds (p-value < 1.5 × 10−6), including one locus on chromosome 11 linked to protein content and 10 loci associated with oil content (chromosomes 1, 5, 11, 16, 17, and 18). The protein-associated locus is located near a gene encoding a CBL-interacting protein kinase, which is involved in key biological processes, including stress response mechanisms such as drought and osmotic stress. The oil-associated loci were linked to genes with diverse functions, including lipid transport, nutrient reservoir activity, and stress responses, such as Sec14p-like phosphatidylinositol transfer proteins and Germin-like proteins. These findings suggest that the loci identified not only influence oil and protein content but may also contribute to plant resilience under environmental stress conditions. The data obtained from this study provide valuable genetic markers that can be used in breeding programs to optimize oil and protein content, particularly in varieties adapted to Russian climates, and contribute to the development of high-yielding, nutritionally enhanced soybean cultivars.

Analysis of stomatal characteristics of maize hybrids and their parental inbred lines during critical reproductive periods

Analysis of stomatal characteristics of maize hybrids and their parental inbred lines during critical reproductive periods

Ac/Ds-like Transposon Elements Inserted in ZmABCG2a Cause Male Sterility in Maize

Using male sterile (MS) lines instead of normal inbred maternal lines in hybrid seed production can increase the yield and quality with lower production costs. Therefore, developing a new MS germplasm is essential for maize hybrid seed production in the future. Here, we reported a male sterility gene ms*-N125, cloned from a newly found MS mutant ms*-N125. This mutant has an underdeveloped tassel that showed impaired glumes and shriveled anthers without pollen grains. The MS locus of ms*-N125 was mapped precisely to a 112-kb-interval on the chromosome 5. This interval contains only three candidate genes, Zm958, Zm959, and Zm960. Sequencing results showed that only candidate Zm960 harbored a 548-bp transposable element (TE) in its 9th exon, and the two other candidate genes were found to have no genetic variations between the mutant and wild type (WT). Thus, Zm960 is the only candidate gene for male sterility of the mutant ms*-N125. In addition, we screened another recessive MS mutant, ms*-P884, which exhibited similar male sterility phenotypes to ms*-N125. Sequencing Zm960 in ms*-P884 showed a 600-bp TE located in its 2nd exon. Zm960 encodes an ATP-binding cassette in the G subfamily of ABC (ABCG) transporters, ZmABCG2a, with both mutants which harbored an Ac/Ds-like transposon in each. To verify the function of ZmABCG2a for male sterility further, we found an ethyl methanesulfonate (EMS) mutant, zmabcg2a*, which displayed male sterility and tassel phenotypes highly similar to ms*-N125 and ms*-P884, confirming that ZmABCG2a must be the gene for male sterility in maize. In addition, the results of lipid metabolome analysis of ms*-N125 young tassels showed that the total lipid content of the mutant was significantly lower than that of the WT, with 15 subclasses of lipids, including PE (phosphatidylethanolamine), PC (phosphatidylcholine), DG (digalactosyldiacylglycerols), and MGDG (monogalactosyldiacylglycerol) which were significantly down-regulated in the ms*-N125 mutant versus its wild type. In summary, we identified alternate mutations of the ZmABCG2a gene, which may be a potential germplasm for hybrid seed production in maize.

Identification of candidate genes for leaf size by QTL mapping and transcriptome sequencing in Brassica napus L

Leaf is the main photosynthetic organ at the seedling stage of rapeseed and leaf size is a crucial agronomic trait affecting rapeseed yield. Understanding the genetic mechanisms underlying leaf size is therefore important for rapeseed breeding. In this study, QTL mapping for three traits related to leaf size, i.e., leaf width (LW), leaf length (LL) and leaf area (LA), was performed using a recombinant inbred line (RIL) population and four QTLs for LW, two QTLs for LL and four QTLs for LA were detected. Transcriptome analysis revealed that differentially expressed genes (DEGs) were enriched in the GO terms related to microtubules, and the expression level of several genes involved in cell division also showed significant differences. Microscopic analysis suggested that the cell number was the main factor regulating leaf size. Combining QTL mapping and RNA sequencing, four promising candidate genes, including BnaA10G0085600ZS, BnaA10G0156900ZS, BnaC03G0441700ZS, and BnaC08G0410600ZS, were proposed to control leaf size by regulating cell division. The results of QTL, transcriptome analysis, and anatomical observation were highly consistent, collectively revealing that genes related to cell division played a crucial role in regulating the leaf size traits in rapeseed. These findings provided further insights into the genetic mechanism of leaf size and built fundamental theory basis for high-density tolerance breeding in rapeseed.

Genome-wide identification and functional roles relating to anthocyanin biosynthesis analysis in maize

BackgroundAnthocyanin is an important class of water-soluble pigments that are widely distributed in various tissues of plants, and it not only facilitates diverse color changes but also plays important roles in various biological processes. Maize silk, serving as an important reproductive organ and displaying a diverse range of colors, plays an indispensable role in biotic resistance through its possession of anthocyanin. However, the copy numbers, characteristics, and expression patterns of genes involved in maize anthocyanin biosynthesis are not fully understood. In this study, gene numbers, distribution, structure, cis-elements of the anthocyanin synthetic gene family were identified, and then the potential transcriptional factors were predicted by two analyzed methods. Finally, genes involved in maize silk pigment were screened by un-targeted metabolism analysis.ResultsTen gene families involved in the maize anthocyanin biosynthesis pathway were identified, and 142 synthetic genes were obtained. These anthocyanin biosynthetic genes have high copy numbers and are normally clustered on chromosomes. The promoters of these synthetic genes contain various cis-elements and the gene expression patterns and transcriptional regulatory networks were analyzed. These genes are distributed on different chromosomes and gene expression patterns vary across different tissues in maize. Specifically, these genes often exhibit higher expression in the stem, leaves, and seeds. Ten highly expressed genes in silks were identified. Based on un-targeted metabolites detection in the silks of four maize representative inbred lines with different colors, two main differential anthocyanin components were identified. Furthermore, the gene expression patterns of the ten highly expressed genes and their potential interacting transcriptional factors were analyzed across the four inbred lines.ConclusionsThe results in this study show a through picture of maize anthocyanin synthetic genes, and the structure and function of genes related to anthocyanin biosynthesis in maize could be further investigated.

FlexLMM: a nextflow linear mixed model framework for GWAS.

Linear mixed models are a commonly used statistical approach in genome-wide association studies when population structure is present. However, naive permutations of the phenotype to empirically estimate the null distribution of a statistic of interest are not appropriate in the presence of population structure or covariates. This is because the samples are not exchangeable with each other under the null hypothesis, and because permuting the phenotypes breaks the relationship among those and eventual covariates. For this reason we developed FlexLMM, a Nextflow pipeline that can perform appropriate permutations in linear mixed models while allowing for flexibility in the definition of the exact statistical model to be used. FlexLMM can set a significance threshold via permutations, thanks to a two-step process where the population structure is first regressed out, and only then are the permutations performed on the uncorrelated residuals. We envision this pipeline will be particularly useful for researchers working on multi-parental crosses among inbred lines of model organisms or farm animals and plants. The source code and documentation for the FlexLMM is available at https://github.com/birneylab/flexlmm.

Genomic strategies to facilitate breeding for increased β-Glucan content in oat (Avena sativa L.)

BackgroundHexaploid oat (Avena sativa L.) is a commercially important cereal crop due to its soluble dietary fiber β-glucan, a hemicellulose known to prevent cardio-vascular diseases. To maximize health benefits associated with the consumption of oat-based food products, breeding efforts have aimed at increasing the β-glucan content in oat groats. However, progress has been limited. To accelerate oat breeding efforts, we leveraged existing breeding datasets (1,230 breeding lines from South Dakota State University oat breeding program grown in multiple environments between 2015 and 2022) to conduct a genome-wide association study (GWAS) to increase our understanding of the genetic control of beta-glucan content in oats and to compare strategies to implement genomic selection (GS) to increase genetic gain for β-glucan content in oat.ResultsLarge variation for β-glucan content was observed with values ranging between 3.02 and 7.24%. An independent GWAS was performed for each breeding panel in each environment and identified 22 loci distributed over fourteen oat chromosomes significantly associated with β-glucan content. Comparison based on physical position showed that 12 out of 22 loci coincided with previously identified β-glucan QTLs, and three loci are in the vicinity of cellulose synthesis genes, Cellulose synthase-like (Csl). To perform a GWAS analysis across all breeding datasets, the β-glucan content of each breeding line was predicted for each of the 26 environments. The overall GWAS identified 73 loci, of which 15 coincided with loci identified for individual environments and 37 coincided with previously reported β-glucan QTLs not identified when performing the GWAS in single years. In addition, 21 novel loci were identified that were not reported in the previous studies. The proposed approach increased our ability to detect significantly associated markers. The comparison of multiple GS scenarios indicated that using a specific set of markers as a fixed effect in GS models did not increase the prediction accuracy. However, the use of multi-environment data in the training population resulted in an increase in prediction accuracy (0.61–0.72) as compared to single-year (0.28–0.48) data. The use of USDA-SoyWheOatBar-3 K genotyping array data resulted in a similar level of prediction accuracy as did genotyping-by-sequencing data.ConclusionThis study identified and confirmed the location of multiple loci associated with β-glucan content. The proposed genomic strategies significantly increase both our ability to detect significant markers in GWAS and the accuracy of genomic predictions. The findings of this study can be useful to accelerate the genetic improvement of β-glucan content and other traits.

Tissue-specific resistance and susceptibility to the tomato brown rugose fruit virus (ToBRFV) conferred by Solanum pennellii loci

BackgroundPlant breeding research heavily relies on wild species, which harbor valuable traits for modern agriculture. This work employed a new introgression population derived from Solanum pennellii (LA5240), a wild tomato native to Peru, composed of 1,900 genotyped backcross inbred lines (BILs_BC2S6) in the tomato inbreds LEA and TOP cultivated genetic backgrounds. This Peruvian accession was found resistant to the most threatening disease of tomatoes today, caused by the tobamovirus tomato brown rugose fruit virus (ToBRFV).ResultsThe BILs were inoculated and genotyped for 5000 single primer enrichment technology (SPET) markers and phenotyped for virus presence, using ELISA, and for visual symptoms in the terminal shoot, axillary shoots, and fruits. Growth of the recombinant BILs in a highly infected greenhouse enabled the mapping of a quantitative trait locus (QTL) for resistance to ToBRFV to chromosome 2 next to tomato mosaic-1 (Tm-1). The QTL reduced the ELISA values and the symptoms of the axillary shoots in both TOP and LEA BILs. Another locus for resistance was mapped to chromosome 3, which protected the terminal and axillary shoots of the TOP BILs only. A strong QTL for fruit susceptibility to ToBRFV was mapped to chromosome 7 only in the LEA background.ConclusionTaken together, S. pennellii loci conferring resistance and susceptibility act in a tissue-specific manner and are modified by genetic background.

Genome-wide association mapping for stay-green and stem reserve mobilization traits in wheat (Triticum aestivum L.) under combined heat and drought stress.

Stay-green (SG) and stem reserve mobilization (SRM) are two significant mutually exclusive traits, which contributes to grain-filling during drought and heat stress in wheat. The current research was conducted in a genome-wide association study (GWAS) panel consisting of 278 wheat genotypes of advanced breeding lines to find the markers linked with SG and SRM traits and also to screen the superior genotypes. SG and SRM traits, viz. soil plant analysis development (SPAD) value, canopy temperature (CT), normalized difference vegetation index (NDVI), leaf senescence rate (LSR) and stem reserve mobilization efficiency (SRE) were recorded. The trial was conducted in α-lattice design, under control and combined heat and drought stress (HD). Analysis of variance and descriptive statistics showed a significant difference across the evaluated traits. The highest mean of SRE (31.7%) and SRM (0.42g/stem) was reported in HD, while highest SRE in HD and lowest in control was 52.56% and 15.7%, respectively. Genotyping was carried out using the 35K Axiom R Wheat Breeder's Array, 14,625 SNPs were kept after filtering. Through GWAS, 36 significant marker trait associations (MTAs) were identified on 16 distinct chromosomes; out of this, 22 MTAs were found under control and 14 MTAs under HD. Candidate genes that code for UDP-glycosyltransferase 73C4-like and protein detoxification 40-like was linked to SPAD and CT respectively. One MTAs was detected for SRM on chromosome 6B that code for wall associated receptor kinase 4 like. These SNPs can be utilized to generate cultivars that adapt to climate change by a marker-assisted gene transfer.

Improvement of Nicotiana tabacum L. for low conversion of nicotine to nornicotine and its effect on morphological traits and chemical composition

Nornicotine is a secondary metabolite formed in tobacco leaves by the oxidative N-demethylation (conversion) of nicotine. Its high level is undesirable because this alkaloid is a precursor of N-nitrosonornicotine, which has been shown to have carcinogenic properties. The aim of the study was to assess the nicotine and nornicotine content in four successive generations of ten tobacco cultivars/breeding lines. The possibility of reducing potentially harmful compounds in the cultivars/breeding lines was also determined. The study was conducted as field experiments between the years 2014 and 2018. The alkaloid content in the leaves was determined by the gas chromatography/ mass spectrometry (GC/MS) method. The systematic assessment of the alkaloid profile of tobacco and eliminating converter plants in four successive generations, particularly within breeding lines characterized by a wide conversion range, made it possible to reduce the nornicotine content and, thus, the potentially carcinogenic compounds in the leaves. Three lines, ZD2, TNX1, and WGLB with a stable conversion rate of ≤3% and low content of nornicotine were obtained. Furthermore, the morphological traits of the isogenic lines ZD2, TNX1 and WGLB, which exhibit markedly different conversion capacity were evaluated. The greenhouse experiment showed that there were significant differences in some morphological traits. The non-converting lines TNX1 and ZD2 produced longer and wider 9th and 15th leaves than the converting analogues. A relationship has been identified between the traits that determine the phenotype of tobacco cultivars/lines and their ability to convert nicotine to nornicotine.

Adaptation of Diverse Maize Germplasm to Spring Season Conditions in Northeast China

Northeast China (NEC) is a major spring maize (Zea mays L.) growing belt, and the outputs substantially influence national grain production. However, the maize grain yield per unit area has little changes in recent years, partially due to the lack of elite germplasm resources and innovation. Therefore, this study aimed to determine the performance of diverse populations in NEC to propose appropriate strategies for the utilization of elite germplasm to broaden the genetic base of Chinese germplasm. Fifteen diverse maize populations from the International Maize and Wheat Improvement Center (CIMMYT) and the U.S. were crossed to two local tester lines, representing Chinese heterotic groups Reid and Lancaster, for evaluating the combining ability and heterosis in three locations (Gongzhuling, Jilin Province, and Harbin and Suihua, Heilongjiang Province) in NEC over two years. The U.S. (BS13(S)C7 and BS31) and Chinese (Ji Syn A) populations exhibited more favorable alleles for high yield potential in all locations tested. Furthermore, the PH6WC × BS31 and PH6WC × Ji Syn A crosses had higher grain yields, and an appropriate number of days to silking, ear height, and resistance to lodging at Gongzhuling and Harbin in NEC. The best strategies for utilizing these diverse germplasms may be to develop new inbred lines from the existing elite populations or improve the grain yield and resistance to lodging of the elite line PH4CV for broadening the genetic base of the Chinese group Lancaster in NEC.

Quantitative Trait Loci for Phenology, Yield, and Phosphorus Use Efficiency in Cowpea

Background/Objectives: Cowpea is an important legume crop in sub-Saharan Africa (SSA) and beyond. However, access to phosphorus (P), a critical element for plant growth and development, is a significant constraint in SSA. Thus, it is essential to have high P-use efficiency varieties to achieve increased yields in environments where little-to- no phosphate fertilizers are applied. Methods: In this study, crop phenology, yield, and grain P efficiency traits were assessed in two recombinant inbred line (RIL) populations across ten environments under high- and low-P soil conditions to identify traits’ response to different soil P levels and associated quantitative trait loci (QTLs). Single-environment (SEA) and multi-environment (MEA) QTL analyses were conducted for days to flowering (DTF), days to maturity (DTM), biomass yield (BYLD), grain yield (GYLD), grain P-use efficiency (gPUE) and grain P-uptake efficiency (gPUpE). Results: Phenotypic data indicated significant variation among the RILs, and inadequate soil P had a negative impact on flowering, maturity, and yield traits. A total of 40 QTLs were identified by SEA, with most explaining greater than 10% of the phenotypic variance, indicating that many major-effect QTLs contributed to the genetic component of these traits. Similarly, MEA identified 23 QTLs associated with DTF, DTM, GYLD, and gPUpE under high- and low-P environments. Thirty percent (12/40) of the QTLs identified by SEA were also found by MEA, and some of those were identified in more than one P environment, highlighting their potential in breeding programs targeting PUE. QTLs on chromosomes Vu03 and Vu08 exhibited consistent effects under both high- and low-P conditions. In addition, candidate genes underlying the QTL regions were identified. Conclusions: This study lays the foundation for molecular breeding for PUE and contributes to understanding the genetic basis of cowpea response in different soil P conditions. Some of the identified genomic loci, many being novel QTLs, could be deployed in marker-aided selection and fine mapping of candidate genes.

Marker-assisted selection in segregating populations of tomatoes for resistance to TYLCV, ToMV, and Fusarium wilt.

Tomato yellow leaf curl virus (TYLCV), tomato mosaic virus (ToMV), and Fusarium wilt are three of tomatoes' most important viral and fungal diseases. In this study, the application of molecular markers associated with tomato yellow leaf curl virus resistance gene (Ty1), tomato mosaic virus resistance gene (Tm2), and Fusarium wilt resistance gene (I-1) (linked marker) were evaluated. In order to optimize and use SNP markers (by HRM diagnostic method) and SCAR markers, segregating populations of tomatoes were produced by self-pollination of commercial hybrid cultivars. For Ty1 and Tm2, a part of the gene was isolated from F3 populations by PCR reaction. After the sequencing of amplicons, the SNPs were identified between genotypes. According to the previous sequences, the proper site of the gene was determined and new primers were designed for PCR and HRM analysis. The results showed that among the genotypes tested for the resistance against the TYLCV virus, Comodoro, Speedy, and Matin genotypes were heterozygous and showed differentiation in the F3 generation, while Namib and SV8320 genotypes were resistant homozygous and their progeny did not show segregation. Regarding the ToMV virus, in the F3 generation of Matin, Comodoro, and Speedy 30, 12.5 and 12.5% of resistant plants were homozygous, respectively. Although a small number of resistant plants were observed among the F3 generation of SV8320 and Speedy, it can be concluded that these two genotypes were also heterozygous for this gene. Finally, concerning Fusarium wilt disease, in the F5 generation, Matin, Comodoro, Speedy, SV8320, and Namib genotypes were all homozygous. In the field experiment of F1, F2, and F3 generation of SV8320 high heritability was observed for yield per plant, days to flowering, and fruit shelf life. Overall, the findings of this study can inform tomato breeding programs aimed at producing resistant inbred lines.

Assessing the success of breeding maize inbred lines with contrasting diferulate concentrations.

The crosslinking of maize cell wall components, particularly mediated by the formation of ferulic acid dimers or diferulates, has been associated with important crop valorization traits such as increased pest resistance, lower forage digestibility, or reduced bioethanol production. However, these relationships were based on studies performed using diverse unrelated inbred lines and/or populations, so genetic background could interfere on these associations. In the present research, the success of a pedigree selection program aimed to obtain inbred lines from a common antecessor with contrasting diferulate concentration was evaluated. From the 10 inbreds lines developed we could validate the success of the breeding program, obtaining 4 inbred lines with significant contrating values of total diferulate content in the pith tissues (two of each group): high (X̅= 0.69mg/g of DW) and low (X̅= 0.35mg/g). Ferulate changes in the same way were also observed: high (X̅= 3.09mg/g of DW) and low (X̅= 1.62mg/g). On the other hand, we found strong and positive correlations between DFAT and individual dimers, and moderate negative correlations between total DFAT and a main cell wall component such as cellulose. However, we did not find a significant effect of DFAT on maize valorization traits, except of a negative effect of DFAT on the concentration of sugars released after the enzimatic hydrolysis of the pith tissues. Interestingly, increasing DFAT in the pith does not seem to affect the digestibility of the forage or the saccharification of the stover residue, highlighting that changes in a specific tissue do not encompass correlated changes in other resources. Overall, we have obtained contrasting inbred lines with diferulates concentration, which could be uselful in further studies focussing in the identification of regions/genes predominantly involved in the hydroxycinnamate biosynthesis pathway and cell wall crosslinking network.

Evaluating Maize Hybrids for Yield, Stress Tolerance, and Carotenoid Content: Insights into Breeding for Climate Resilience.

To ensure food and feed security, modern maize hybrids must not only perform well under changing climate conditions but also consistently achieve higher and stable yields, exhibit maximum tolerance to stress factors, and produce high quality grains. In a study conducted in 2022 and 2023, 50 maize hybrids were developed from crosses of five elite (highly productive) inbred lines and ten lines possessing favorable genes for carotenoid content. These hybrids were tested under particularly unfavorable conditions for maize cultivation. The aim was to identify which lines effectively transmit the desired traits to the offspring (general combining ability-GCA), and to identify superior hybrids in terms of productivity, adaptability, and quality (specific combining ability-SCA). The study revealed that total carotenoids ranged from 2.30 to 40.20 μg/g for the inbred lines and from 7.45 to 25.08 μg/g for hybrids. A wider distribution of values was observed in the inbred lines compared to the hybrids for key carotenoids such as lutein, zeaxanthin, β-cryptoxanthin, and β-carotene. Among the hybrids, notable performers in yield, adaptability, and carotenoid content included E390×D302, A452×D302, and A447×D302. The paternal inbred line D302 exhibited a high general combining ability for yield (1446 kg ha-1) and, when crossed with several inbred lines, produced hybrids with enhanced yields and higher levels of zeaxanthin, lutein, and β-carotene, as well as improved unbroken plants percent.

Different MHC class I cell surface expression levels in diverse chicken lines, associations with B blood group, and proposed relationship to antigen-binding repertoire

The Major Histocompatibility Complex (MHC) is a cluster of genes with primarily immune-related functions. The MHC class I genes are responsible for self- versus non-self-recognition and viral antigen presentation to T lymphocytes. The chicken MHC class I protein binds its cognate antigen(s) over a repertoire spectrum ranging from promiscuous (generalist) to fastidious (specialist). The MHC class I protein expression level at the cell surface is inversely related to the promiscuity of its peptide-binding repertoire. In our study, erythrocytes from 6 diverse and highly inbred lines of chickens, a closed broiler line, and a highly advanced intercross line were evaluated for MHC class I antigen expression level by flow cytometry using monoclonal antibodies to chicken MHC class I molecules. In chickens, the B blood group antigens include the MHC class I antigen expressed from the MHC. Thus, the B blood group has historically been used as a genetic marker for Marek's Disease virus response. Erythrocytes of the inbred lines were blood typed by serology. The B21 blood type is widely recognized as relatively resistant to Marek's disease and regarded as an MHC class I generalist with low MHC class I expression. The Spanish line, which types serologically as B21.1 (similar to B21), was the lowest MHC class I expressing line. The two sublines (B5.1 and B15.2) of the Fayoumi breed, which significantly differed in their MHC class I expression, also differ in response to multiple pathogens. These defined genetic lines of chickens, with distinct MHC class I expression levels, provide an excellent platform to further interrogate the hypothesis of high or low MHC class I expression (antigenic specialists or generalists, respectively) determining diverse responses to pathogens.

Stochastic variation in foraging traits within inbred lines of Drosophila.

Investigating the causes and consequences of niche partitioning in populations is a major goal in ecology and evolutionary biology. Previous studies have investigated genetic and environmentally induced variation in resource utility and their ecological implications. However, few studies have explored variability (non-genetic, stochastic variation) as a factor contributing to variation in resource utility. In this study, we studied the variability in foraging traits of Drosophila lutescens, a species of wild fruit fly. Using 70 iso-female lines from a single population, we observed two foraging traits, i.e., locomotive speed and resource preferences, in an "8"-shaped experimental arena containing different types of fruit juices. The mean locomotive speed and relative preference for orange juice over grape juice varied significantly among iso-female lines. Additionally, the degree of intraline variation (variability) was detected a fold-change of larger than 2-fold between the smallest line and the largest line. While the mean locomotive speed itself did not correlate with mean resource preferences, the variability of locomotive speed significantly correlated with that of resource preferences. These results suggest that the degree of variability within inbred lines for both locomotive activity and resource preference is potentially partly genetic and that a shared genetic basis may govern variability in these traits. The variability of a particular trait is considered to interact cooperatively with the variability of several other traits in creating phenotypic intraspecific variation within a population.