41 research outputs found
Genetic Resources 2(3)
Genetic Resources is an open access journal disseminating global knowledge and tools used by the community of practitioners of plant, animal and forest genetic resources involved in monitoring, collecting, maintaining, conserving, characterizing and using genetic resources for food, agriculture and forestry. Genetic Resources publishes original research as well as methods, strategies, guidelines, case studies or reviews on a variety of topics of interest on the present and future use of genetic resources. These may include the documentation, conservation, management, assessment, characterization and evaluation of genetic resources and their link to broader biodiversity, socioeconomic practices, policy guidelines or similar, serving stakeholders within and across sectors. Occasionally, Genetic Resources publishes special issues with a focus on selected topics of interest for the genetic resources community. The journal welcomes contributions from all world regions
Genetic Resources 2(4)
Genetic Resources is an open access journal disseminating global knowledge and tools used by the community of practitioners of plant, animal and forest genetic resources involved in monitoring, collecting, maintaining, conserving, characterizing and using genetic resources for food, agriculture and forestry. Genetic Resources publishes original research as well as methods, strategies, guidelines, case studies or reviews on a variety of topics of interest on the present and future use of genetic resources. These may include the documentation, conservation, management, assessment, characterization and evaluation of genetic resources and their link to broader biodiversity, socioeconomic practices, policy guidelines or similar, serving stakeholders within and across sectors. Occasionally, Genetic Resources publishes special issues with a focus on selected topics of interest for the genetic resources community. The journal welcomes contributions from all world regions
Genetic Resources â A new attempt at serving the community
Through the Horizon 2020 project 'GenRes Bridge' the new journal Genetic Resources was conceived to serve as a new cross-cutting platform for stakeholders and practitioners in genetic resources. Its ambition is to provide access to relevant information and tools for the monitoring, conservation, management, characterization and use of genetic resources, and thus to contribute to the FAO global plans of action on genetic resources. Conceived to fill the gaps left by the discontinuation of the journals Plant Genetic Resources Newsletter and Animal Genetic Resources, it aims at serving the genetic resources community worldwide and across sectors
Fine mapping and identification of candidate genes for the sy-2 locus in a temperature-sensitive chili pepper (Capsicum chinense)
Key message
The sy-2 temperature-sensitive gene from Capsicum chinense was fine mapped to a 138.8-kb region at the distal portion of pepper chromosome 1. Based on expression analyses, two putative F-box genes were identified as sy-2 candidate genes.
Abstract
Seychelles-2 (sy-2) is a temperature-sensitive natural mutant of Capsicum chinense, which exhibits an abnormal leaf phenotype when grown at temperatures below 24 °C. We previously showed that the sy-2 phenotype is controlled by a single recessive gene, sy-2, located on pepper chromosome 1. In this study, a high-resolution genetic and physical map for the sy-2 locus was constructed using two individual F2 mapping populations derived from a cross between C. chinense mutant sy-2 and wild-type No. 3341. The sy-2 gene was fine mapped to a 138.8-kb region between markers SNP 5-5 and SNP 3-8 at the distal portion of chromosome 1, based on comparative genomic analysis and genomic information from pepper. The sy-2 target region was predicted to contain 27 genes. Expression analysis of these predicted genes showed a differential expression pattern for ORF10 and ORF20 between mutant and wild-type plants; with both having significantly lower expression in sy-2 than in wild-type plants. In addition, the coding sequences of both ORF10 and ORF20 contained single nucleotide polymorphisms (SNPs) causing amino acid changes, which may have important functional consequences. ORF10 and ORF20 are predicted to encode F-box proteins, which are components of the SCF complex. Based on the differential expression pattern and the presence of nonsynonymous SNPs, we suggest that these two putative F-box genes are most likely responsible for the temperature-sensitive phenotypes in pepper. Further investigation of these genes may enable a better understanding of the molecular mechanisms of low temperature sensitivity in plants.OAIID:RECH_ACHV_DSTSH_NO:T201625254RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A076900CITE_RATE:3.9FILENAME:TAG(2016) Fine mapping and identification of candidate genes for sy2.pdfDEPT_NM:ìëŹŒìì°êłŒíë¶EMAIL:[email protected]_YN:YFILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/c773c8d3-fc79-496f-af60-fa1b9b2e214e/linkCONFIRM:
Development and application of Single Primer Enrichment Technology (SPET) SNP assay for population genomics analysis and candidate gene discovery in lettuce
Single primer enrichment technology (SPET) is a novel high-throughput genotyping method based on short-read sequencing of specific genomic regions harboring polymorphisms. SPET provides an efficient and reproducible method for genotyping target loci, overcoming the limits associated with other reduced representation library sequencing methods that are based on a random sampling of genomic loci. The possibility to sequence regions surrounding a target SNP allows the discovery of thousands of closely linked, novel SNPs. In this work, we report the design and application of the first SPET panel in lettuce, consisting of 41,547 probes spanning the whole genome and designed to target both coding (~96%) and intergenic (~4%) regions. A total of 81,531 SNPs were surveyed in 160 lettuce accessions originating from a total of 10 countries in Europe, America, and Asia and representing 10 horticultural types. Model ancestry population structure clearly separated the cultivated accessions (Lactuca sativa) from accessions of its presumed wild progenitor (L. serriola), revealing a total of six genetic subgroups that reflected a differentiation based on cultivar typology. Phylogenetic relationships and principal component analysis revealed a clustering of butterhead types and a general differentiation between germplasm originating from Western and Eastern Europe. To determine the potentiality of SPET for gene discovery, we performed genome-wide association analysis for main agricultural traits in L. sativa using six models (GLM naive, MLM, MLMM, CMLM, FarmCPU, and BLINK) to compare their strength and power for association detection. Robust associations were detected for seed color on chromosome 7 at 50 Mbp. Colocalization of association signals was found for outer leaf color and leaf anthocyanin content on chromosome 9 at 152 Mbp and on chromosome 5 at 86 Mbp. The association for bolting time was detected with the GLM, BLINK, and FarmCPU models on chromosome 7 at 164 Mbp. Associations were detected in chromosomal regions previously reported to harbor candidate genes for these traits, thus confirming the effectiveness of SPET for GWAS. Our findings illustrated the strength of SPET for discovering thousands of variable sites toward the dissection of the genomic diversity of germplasm collections, thus allowing a better characterization of lettuce collections
Fine mapping of Restorer-of-fertility in pepper (Capsicum annuum L.) identified a candidate gene encoding a pentatricopeptide repeat (PPR)-containing protein
Key message
Using fine mapping techniques, the genomic region co-segregating with Restorer-of-fertility (Rf) in pepper was delimited to a region of 821 kb in length. A PPR gene in this region, CaPPR6, was identified as a strong candidate for Rf based on expression pattern and characteristics of encoding sequence.
Abstract
Cytoplasmic-genic male sterility (CGMS) has been used for the efficient production of hybrid seeds in peppers (Capsicum annuum L.). Although the mitochondrial candidate genes that might be responsible for cytoplasmic male sterility (CMS) have been identified, the nuclear Restorer-of-fertility (Rf) gene has not been isolated. To identify the genomic region co-segregating with Rf in pepper, we performed fine mapping using an Rf-segregating population consisting of 1068 F2 individuals, based on BSA-AFLP and a comparative mapping approach. Through six cycles of chromosome walking, the co-segregating region harboring the Rf locus was delimited to be within 821 kb of sequence. Prediction of expressed genes in this region based on transcription analysis revealed four candidate genes. Among these, CaPPR6 encodes a pentatricopeptide repeat (PPR) protein with PPR motifs that are repeated 14 times. Characterization of the CaPPR6 protein sequence, based on alignment with other homologs, showed that CaPPR6 is a typical Rf-like (RFL) gene reported to have undergone diversifying selection during evolution. A marker developed from a sequence near CaPPR6 showed a higher prediction rate of the Rf phenotype than those of previously developed markers when applied to a panel of breeding lines of diverse origin. These results suggest that CaPPR6 is a strong candidate for the Rf gene in pepper.OAIID:RECH_ACHV_DSTSH_NO:T201625308RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A076900CITE_RATE:3.9FILENAME:TAG(2016) Fine mapping of Rf in pepper.pdfDEPT_NM:ìëŹŒìì°êłŒíë¶EMAIL:[email protected]_YN:YFILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/8c5822f8-5600-4a60-a386-0529e2f49934/linkCONFIRM:
Global Analysis of Arabidopsis/Downy Mildew Interactions Reveals Prevalence of Incomplete Resistance and Rapid Evolution of Pathogen Recognition
Interactions between Arabidopsis thaliana and its native obligate oomycete pathogen Hyaloperonospora arabidopsidis (Hpa) represent a model system to study evolution of natural variation in a host/pathogen interaction. Both Arabidopsis and Hpa genomes are sequenced and collections of different sub-species are available. We analyzed âŒ400 interactions between different Arabidopsis accessions and five strains of Hpa. We examined the pathogen's overall ability to reproduce on a given host, and performed detailed cytological staining to assay for pathogen growth and hypersensitive cell death response in the host. We demonstrate that intermediate levels of resistance are prevalent among Arabidopsis populations and correlate strongly with host developmental stage. In addition to looking at plant responses to challenge by whole pathogen inoculations, we investigated the Arabidopsis resistance attributed to recognition of the individual Hpa effectors, ATR1 and ATR13. Our results suggest that recognition of these effectors is evolutionarily dynamic and does not form a single clade in overall Arabidopsis phylogeny for either effector. Furthermore, we show that the ultimate outcome of the interactions can be modified by the pathogen, despite a defined gene-for-gene resistance in the host. These data indicate that the outcome of disease and disease resistance depends on genome-for-genome interactions between the host and its pathogen, rather than single gene pairs as thought previously
Carrot genetic diversity in Europe based on breeding traits
ECPGR European Evaluation Network (EVA
Computational Prediction and Molecular Characterization of an Oomycete Effector and the Cognate Arabidopsis Resistance Gene
Hyaloperonospora arabidopsidis (Hpa) is an obligate biotroph oomycete pathogen of the model plant Arabidopsis thaliana and contains a large set of effector proteins that are translocated to the host to exert virulence functions or trigger immune responses. These effectors are characterized by conserved amino-terminal translocation sequences and highly divergent carboxyl-terminal functional domains. The availability of the Hpa genome sequence allowed the computational prediction of effectors and the development of effector delivery systems enabled validation of the predicted effectors in Arabidopsis. In this study, we identified a novel effector ATR39-1 by computational methods, which was found to trigger a resistance response in the Arabidopsis ecotype Weiningen (Wei-0). The allelic variant of this effector, ATR39-2, is not recognized, and two amino acid residues were identified and shown to be critical for this loss of recognition. The resistance protein responsible for recognition of the ATR39-1 effector in Arabidopsis is RPP39 and was identified by map-based cloning. RPP39 is a member of the CC-NBS-LRR family of resistance proteins and requires the signaling gene NDR1 for full activity. Recognition of ATR39-1 in Wei-0 does not inhibit growth of Hpa strains expressing the effector, suggesting complex mechanisms of pathogen evasion of recognition, and is similar to what has been shown in several other cases of plant-oomycete interactions. Identification of this resistance gene/effector pair adds to our knowledge of plant resistance mechanisms and provides the basis for further functional analyses
Genetic and phenotypic evaluation of european maize landraces as a tool for conservation and valorization of agrobiodiversity
The ECPGR European Evaluation Network (EVA) for Maize involves genebanks, research institutions, and private breeding companies from nine countries focusing on the valorization of maize genetic resources across Europe. This study describes a diverse collection of 626 local landraces and traditional varieties of maize (Zea mays L.) from nine European genebanks, including criteria for selection of the collection and its genetic and phenotypic diversity. High-throughput pool genotyping grouped the landraces into nine genetic groups with a threshold of 0.6 admixture, while 277 accessions were designated admixed and likely to have resulted from previous breeding activities. The grouping correlated well with the geographic origins of the collection, also reflecting the various pathways of introduction of maize to Europe. Phenotypic evaluations of 588 accessions for flowering time and plant architecture in multilocation trials over three years confirmed the great diversity within the collection, although phenotypic clusters only partially correlated with the genetic grouping. The EVA approach promotes conservation of genetic resources and opens an opportunity to increase genetic variability for developing improved varieties and populations for farmers, with better adaptation to specific environments and greater tolerance to various stresses. As such, the EVA maize collection provides valuable sources of diversity for facing climate change due to the varietiesâ local adaptation