A major QTL controlling apple skin russeting maps on the linkage group 12 of 'Renetta Grigia di Torriana'

Background: Russeting is a disorder developed by apple fruits that consists of cuticle cracking followed by the replacement of the epidermis by a corky layer that protects the fruit surface from water loss and pathogens. Although influenced by many environmental conditions and orchard management practices, russeting is under genetic control. The difficulty in classifying offspring and consequent variable segregation ratios have led several authors to conclude that more than one genetic determinant could be involved, although some evidence favours a major gene (Ru). Results: In this study we report the mapping of a major genetic russeting determinant on linkage group 12 of apple as inferred from the phenotypic observation in a segregating progeny derived from 'Renetta Grigia di Torriana', the construction of a 20 K Illumina SNP chip based genetic map, and QTL analysis. Recombination analysis in two mapping populations restricted the region of interest to approximately 400 Kb. Of the 58 genes predicted from the Golden Delicious sequence, a putative ABCG family transporter has been identified. Within a small set of russeted cultivars tested with markers of the region, only six showed the same haplotype of 'Renetta Grigia di Torriana'. Conclusions: A major determinant (Ru_RGT) for russeting development putatively involved in cuticle organization is proposed as a candidate for controlling the trait. SNP and SSR markers tightly co-segregating with the Ru_RGT locus may assist the breeder selection. The observed segregations and the analysis of the 'Renetta Grigia di Torriana' haplotypic region in a panel of russeted and non-russeted cultivars may suggest the presence of other determinants for russeting in apple

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

An easy and robust method for isolation and validation of single-nucleotide polymorphic markers from a first Erysiphe alphitoides draft genome

Isolating genetic markers is often costly and time-consuming for non-model fungal species. However, these markers are of primary importance to identify the origin of invasive species and to infer their reproductive mode and dispersal ability. We slightly modified a recent molecular method to quickly isolate and validate single-nucleotide polymorphism (SNP) markers, from a first Erysiphe alphitoides draft genome, one of the main causal agent of oak powdery mildew in Europe. Although the draft assembly was strongly fragmented (555,289 contigs), we successfully isolated 1700 SNPs from 75 single-copy genes conserved in most fungal genomes. Ninety percent of them allowed to clearly distinguish the two main Erysiphe species reported on European oaks: E. alphitoides and E. quercicola. Thirty-six SNPs, located in distinct genes, were then validated using a strategy of MassArray genotyping on 95 E. alphitoides isolates sampled in Europe. This genotyping showed that only monospore isolates had the expected haploid signature, whereas direct genotyping from field leaves showed signature of mixed infection. Considering haploid isolates, these markers led to the first results of population genetic diversity, and suggested that E. quercicola may have a more asexual reproduction than its sister species, E. alphitoides