The isolation and purification of DNA from Vitis vinifera L. plants and in vitro cultures

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Methylated DNA changes associated with the initiation and maintenance of Vitis vinifera in vitro shoot and callus cultures: A possible mechanism for age-related changes

Tissue culture technologies are an important aspect of the genetic modification of grapevine (Vitis vinifera). The molecular basis of this phenomenon is not well understood, however, the extent of DNA methylation is recognised as a factor in the control of gene expression. This study explores the possibility that DNA methylation may have a role in grapevine culture responses. DNA methylation profiles were constructed for Vitis vinifera, cv. Sultanina, during plantlet micropropagation, callus induction and proliferation. Methylation of genomic DNA and ribosomal RNA genes (rDNA) was found in glasshouse-grown plants, micropropagated plantlets and callus cultures. An analysis of rDNA showed that glasshouse-grown plants had 74.6% of the recognition sequences for Hpa II methylated at the internal cytosine position CmCGG, whereas 7.7% of the recognition sequences appeared to be methylated at the external cytosine (mCmCGG). The rDNA profiles of micropropagated subcultures S0 (initial subcultures) and S4 (fourth subcultures), representing one year of in vitro growth, showed that the percentage of recognition sequences containing a methylated external cytosine increased from 7.7% in glasshouse-grown plants to 64.5% for S-0 and 72.5% for the S4 subculture. The implications of these findings for the in vitro manipulation of grapevine used in genetic modifications are discussed

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