Inter clonal genomic variation in Vitis vinifera L. cv. Malbec

CALDERÓN, LUCIANO; LIJAVETZKY, D

Foz do Iguazu

Congreso; XXII International Congress of Genetics (ICG); 2018

Somatic mutations are a major force introducing novel genetic variation; this rolebecomes enhanced in systems lacking of sexual reproduction. This is the case ofgrapevines used in the wine industry. Here clonal propagation through asexual cuttings isthe regular practice, in order to preserve quality traits of productive relevance.Nonetheless, a remarkable phenotypic variation has been reported among clones withincultivars. However, less is known about the intra-cultivar genetic variability and itspotential impact on the phenotype. Here we characterize the clonal genetic variabilityof Vitis vinifera L. cv. Malbec, which is the main cultivar for Argentine viticulture. Weperformed a genome wide analysis of four Malbec clones, obtaining Illumina reads at a35x depth for each clone. Bioinformatic tools were employed to align our sequences tothe reference genome (genotype PN40024). We implemented variant calling pipelines forsingle nucleotide variations (SNVs) discovery, and applied strict quality filters todetermine a set of reliable SNVs. We discovered ca. 2.6 million SNVs that distinguish cv.Malbec from the reference genome, and identified between 22 and 29 thousand SNVsthat are unique for each of the four sequenced clones. The predicted effect on geneexpression of the clone-specific SNVs indicated that 60% occurred in non-coding regions;however, 40% occurred both in regulatory and exonic regions. We found a notoriousclonal genetic variability, consequence of somatic mutations accumulation. Moreover, ourin silico analyses showed that some clone-specific SNVs could be affecting geneexpression, possibly explaining part of the phenotypic variation reported for Malbec.