Biology subjects

Antanaviciute, L.

Publications and source records attributed to Antanaviciute, L..

3 recordsLinked to original sources

bioRxiv2019

High-quality, genome-wide SNP genotypic data for pedigreed germplasm of the diploid outbreeding species apple, peach, and sweet cherry through a common workflow

High-quality genotypic data is a requirement for many genetic analyses. For any crop, errors in genotype calls, phasing of markers, linkage maps, pedigree records, and unnoticed variation in ploidy levels can lead to spurious marker-locus-trait associations and incorrect origin assignment of alleles to individuals. High-throughput genotyping requires automated scoring, as manual inspection of thousands of scored loci is too time-consuming. However, automated SNP scoring can result in errors that should be corrected to ensure recorded genotypic data are accurate and thereby ensure confidence in downstream genetic analyses. To enable quick identification of errors in a large genotypic data set, we have developed a comprehensive workflow. This multiple-step workflow is based on inheritance principles and on removal of markers and individuals that do not follow these principles, as demonstrated here for apple, peach, and sweet cherry. Genotypic data was obtained on pedigreed germplasm using 6-9K SNP arrays for each crop and a subset of well-performing SNPs was created using ASSIsT. Use of correct (and corrected) pedigree records readily identified violations of simple inheritance principles in the genotypic data, streamlined with FlexQTL software. Retained SNPs were grouped into haploblocks to increase the information content of single alleles and reduce computational power needed in downstream genetic analyses. Haploblock borders were defined by recombination locations detected in ancestral generations of cultivars and selections. Another round of inheritance-checking was conducted, for haploblock alleles (i.e., haplotypes). High-quality genotypic data sets were created using this workflow for pedigreed collections representing the U.S. breeding germplasm of apple, peach, and sweet cherry evaluated within the RosBREED project. These data sets contain 3855, 4005, and 1617 SNPs spread over 932, 103, and 196 haploblocks in apple, peach, and sweet cherry, respectively. The highly curated phased SNP and haplotype data sets, as well as the raw iScan data, of germplasm in the apple, peach, and sweet cherry Crop Reference Sets is available through the Genome Database for Rosaceae.

genetics↗

bioRxiv2018

Identification of powdery mildew resistance QTL in Fragaria x ananassa

The obligate biotrophic fungus Podosphaera aphanis is the causative agent of powdery mildew on cultivated strawberry (Fragaria x ananassa). Genotypes from two bi-parental mapping populations Emily x Fenella and Redgauntlet x Hapil were phenotyped for powdery mildew disease severity in a series of field trials. Here we report multiple QTL associated with resistance to powdery mildew, identified in ten phenotyping events conducted across different years and locations. Seven QTL show a level of stable resistance across multiple phenotyping events however many other QTL were represented in a single phenotyping event and therefore must be considered transient. One of the identified QTL was closely linked to an associated resistance gene across the wider germplasm. Furthermore, a preliminary association analysis identified a novel conserved locus for further investigation. Our data suggests that resistance is highly complex and that multiple additive sources of quantitative resistance to powdery mildew exist across strawberry germplasm. Implementation of the reported markers in marker-assisted breeding or genomic selection would lead to improved powdery mildew resistant strawberry cultivars, particularly where the studied parents, progeny and close pedigree material are included in breeding germplasm.\n\nKey MessagePowdery mildew resistance in two strawberry mapping populations is controlled by both stable and transient novel QTL of moderate effect. Some transferability of QTL across wider germplasm was observed.

pathology↗

bioRxiv2017

Vegetative compatibility groups explain variation in the virulence of Verticillium dahliae on strawberry

Verticillium dahliae infection of strawberry (Fragaria x ananassa) is a major cause of disease-induced wilting in soil-grown strawberries across the world. To understand what components of the pathogen are affecting disease expression, the presence of the known effector VdAve1 was screened in a sample of Verticillium dahliae isolates. Isolates from strawberry were found to contain VdAve1 and were divided into two major clades, based upon their vegetative compatibility groups (VCG); no UK strawberry isolates contained VdAve1. VC clade was strongly related to their virulence levels. VdAve1-containing isolates pathogenic on strawberry were found in both clades, in contrast to some recently published findings.\n\nOn strawberry, VdAve1-containing isolates had significantly higher virulence during early infection, which diminished in significance as the infection progressed. Transformation of a virulent non-VdAve1 containing isolate, with VdAve1 was found neither to increase nor decrease virulence when inoculated on a susceptible strawberry cultivar. There are therefore virulence factors that are epistatic to VdAve1 and potentially multiple independent routes to high virulence on strawberry in V. dahliae lineages.\n\nGenome sequencing a subset of isolates across the two VCGs revealed that isolates were differentiated at the whole genome level and contained multiple changes in putative effector content, indicating that different clonal VCGs may have evolved different strategies for infecting strawberry, leading to different virulence levels in pathogenicity tests. It is therefore important to consider both clonal lineage and effector complement as the adaptive potential of each lineage will differ, even if they contain the same race determining effector.

plant biology↗