Identification of stable QTLs for vegetative and reproductive traits in the microvine (Vitis vinifera L.) using the 18 K Infinium chip

UMR AGAP - équipe DAAV - Diversité, adaptation et amélioration de la vigne[b]Background[/b] [br/]The increasing temperature associated with climate change impacts grapevine phenology and development with critical effects on grape yield and composition. Plant breeding has the potential to deliver new cultivars with stable yield and quality under warmer climate conditions, but this requires the identification of stable genetic determinants. This study tested the potentialities of the microvine to boost genetics in grapevine. A mapping population of 129 microvines derived from Picovine x Ugni Blanc flb, was genotyped with the Illumina® 18 K SNP (Single Nucleotide Polymorphism) chip. Forty-three vegetative and reproductive traits were phenotyped outdoors over four cropping cycles, and a subset of 22 traits over two cropping cycles in growth rooms with two contrasted temperatures, in order to map stable QTLs (Quantitative Trait Loci). [br/][b]Results[/b] [br/]Ten stable QTLs for berry development and quality or leaf area were identified on the parental maps. A new major QTL explaining up to 44 % of total variance of berry weight was identified on chromosome 7 in Ugni Blanc flb, and co-localized with QTLs for seed number (up to 76 % total variance), major berry acids at green lag phase (up to 35 %), and other yield components (up to 25 %). In addition, a minor QTL for leaf area was found on chromosome 4 of the same parent. In contrast, only minor QTLs for berry acidity and leaf area could be found as moderately stable in Picovine. None of the transporters recently identified as mutated in low acidity apples or Cucurbits were included in the several hundreds of candidate genes underlying the above berry QTLs, which could be reduced to a few dozen candidate genes when a priori pertinent biological functions and organ specific expression were considered. [br/][b]Conclusions[/b] [br/]This study combining the use of microvine and a high throughput genotyping technology was innovative for grapevine genetics. It allowed the identification of 10 stable QTLs, including the first berry acidity QTLs reported so far in a Vitis vinifera intra-specific cross. Robustness of a set of QTLs was assessed with respect to temperature variatio

Molecular mapping of grapevine genes

In this chapter, we review the history of grapevine genetics and gene mapping. Genetic markers are introduced considering both sequence-based and sequence-independent approaches used for variant discovery. We provide a survey of genotyping tools, from low- to high-throughput platforms. We describe general principles of map building and implementation, highlighting specificities for outbred species such as the grapevine. Then, we review the different approaches applied for QTL identification according to the genetic material, from bi-parental progenies, pedigree-supported segregating populations, to germplasm collection. In particular, our emphasis is on the relevance of such studies for the dissection of a complex trait. We describe the difficult process of identifying genes responsible for QTLs and the few cases of QTL cloning. Many years have passed from the first grapevine marker isolation, the development of genetic and physical maps, until the deciphering of the genome sequence. With such a wealth of detailed information on wild and cultivated grapevines, we discuss how data sharing and multidisciplinary data integration are the current challenges that the scientific community faces to effectively translate knowledge into practic

PediaVirus chatline: all together against COVID-19

On occasion of the COVID-19 pandemic, in Italy, during the outbreak period, 140 professionals, including paediatricians (the majority), general health practitioners, infectious diseases specialists, epidemiologists, neuropsychiatrists, neurologists, psychologists, pharmaceutical representatives, magistrates, predominantly Italian but also from other countries in Europe and beyond, created a chatline to share their own experiences.The results of such investigation have been reported in this report