Update of the PHYLLI international database for grape phylloxera: aims and challenges

Abstract

The International Phylloxera Genotype Database “PHYLLI” which is supported by the 2014 ISHS Phylloxera group describes Grape Phylloxera (Daktulosphaira vitifoliae) genotypes, which are genotyped by seven SSR markers (Dvit6, DVSSR4, DV4, DV8, Phy_III_36, Phy_III_55, Phy_III_30). The samples are standardised by single founder lineages, that are equally biotyped. The advantages of this approach are:

• Distinguishing among sexual vs. asexually reproduction (on a population level)
• Comparing phylloxera genotypes against defined biotypes (deposited in the database)
• Tracing the origin of overwintering “wandering” asexual larvae adapted to leaf-galling in commercial vineyards (biotypes G).

Using the PHYLLI standardised marker approach remains a viable, but limited, approach. Therefore, it is necessary to develop strategies and devising measures to control aggressives phylloxera strains. Modern, more effective molecular technologies are needed to quickly and effectively barcode biotypes by identifying relevant effector genes induced by the phylloxera–host interaction. Current research in the scientific community is evolving to develop genome-based markers to effectively (quick and cost-effective) defining phylloxera biotypes based on effector genes. At this point we maintain the PHYLLI database (based on microsatellites) to bridge this gap. We are aware that this requires the parallel monitoring and maintenance of single founder lineage insects’ performance (as standard biotypes) until relevant effector genes(s) have been confirmed.