In this study, the transcriptome of Vitis flexuosa leaves inoculated with Elsinoe ampelina was analysed to identify useful genes and elucidate their function and differential expression patterns through assembly and annotation gene ontology of data from sequencing short reads on the Illumina platform. We assembled ~121 million high-quality trimmed reads using Velvet and Oases with optimal parameters into a non-redundant set of 70,899 transcripts ( ≥ 200 bp in length). The transcripts exhibited an average length of 1138 bp and a N50 length of 1695 bp, with the largest contig length being 9623 bp. Functional categorization revealed the conservation of genes involved in various molecular functions, including protein binding (21.1%) and oxidoreductase activity (11.7%), in V. flexuosa. The V. flexuosa transcript set generated in this study will serve as a resource for gene discovery and development of functional molecular markers.

Grapevine cultivar identification is based mainly on two complementary methodologies: microsatellite (simple sequence repeat (SSR)) DNA analysis and traditional ampelography. Here, we report a direct multiplex PCR approach that allows the simultaneous amplification of 11 SSR loci from crude samples, i.e. bypassing DNA extraction, by using an engineered DNA polymerase improved to tolerate plant PCR inhibitors. Many different plant tissues were successfully amplified: leaf, root, wood, berry flesh and skin, stalk and must, from wine and table grape varieties, and rootstocks. The direct multiplex PCR that we propose is quicker and cheaper than the methodologies used until now, and provides accurate results. Thus, SSR DNA analysis becomes economically more accessible to a larger number of potential users in addition to research institutes.

Grape phylloxera, Daktulosphaira vitifoliae Fitch, is an important pest of grapevines (Vitis vinifera L.) (Vitaceae). The distribution and frequency of phylloxera clone lineages vary within infested regions of Australia, suggesting the introduction of separate lineages of D. vitifoliae with host associations. Virulence levels of particular phylloxera clones may vary on V. vinifera, but much of this evidence is indirect. In this study, we directly tested the performance of phylloxera clones on V. vinifera using an established excised root assay and a new glasshouse vine assessment. In the root assay, grape phylloxera clones differed in egg production and egg to adult survivorship. In the vine assay, clones differed in the number of immature and adult life stages on roots. In addition vine characteristics, including mean stem weight, root weight, leaf chlorophyll and leaf area, were affected by different phylloxera clones. The two most widespread clones displayed high levels of virulence. These results point to only some phylloxera clones being highly virulent on V. vinifera, helping to explain patterns of field damage, phylloxera distributions and continued survival and production of V. vinifera vines in some infested areas.