BackgroundGrape phylloxera (Daktulosphaira vitifoliae Fitch) is a major insect pest that negatively impacts commercial grapevine performance worldwide. Consequently, the use of phylloxera resistant rootstocks is an essential component of vineyard management. However, the majority of commercially available rootstocks used in viticulture production provide limited levels of grape phylloxera resistance, in part due to the adaptation of phylloxera biotypes to different Vitis species. Therefore, there is pressing need to develop new rootstocks better adapted to specific grape growing regions with complete resistance to grape phylloxera biotypes.ResultsGrapevine rootstock breeding material, including an accession of Vitis cinerea and V. aestivalis, DRX55 ([M. rotundifolia x V. vinifera] x open pollinated) and MS27-31 (M. rotundifolia specific hybrid), provided complete resistance to grape phylloxera in potted plant assays. To map the genetic factor(s) of grape phylloxera resistance, a F1 V. cinerea x V. vinifera Riesling population was screened for resistance. Heritability analysis indicates that the V. cinerea accession contained a single allele referred as RESISTANCE TO DAKTULOSPHAIRA VITIFOLIAE 2 (RDV2) that confers grape phylloxera resistance. Using genetic maps constructed with pseudo-testcross markers for V. cinerea and Riesling, a single phylloxera resistance locus was identified in V. cinerea. After validating SNPs at the RDV2 locus, interval and linkage mapping showed that grape phylloxera resistance mapped to linkage group 14 at position 16.7 cM.ConclusionThe mapping of RDV2 and the validation of markers linked to grape phylloxera resistance provides the basis to breed new rootstocks via marker-assisted selection that improve vineyard performance.Electronic supplementary materialThe online version of this article (10.1186/s12870-018-1590-0) contains supplementary material, which is available to authorized users.

Background and Aims In Australia, hot water immersion and steam application are recommended disinfestation strategies for harvesting bins, vineyard machinery and vehicles against grape phylloxera, Daktulosphaira vitifoliae Fitch. This study validated the effectiveness of these two strategies against genetically diverse phylloxera strains. Methods and Results The first instars of six phylloxera genetic strains, G1, G4, G7, G19, G20 and G30, were subjected to steam projected from 8 and 24 cm, and from 92 cm for G1 only, for 10, 20 and 30 s. All steam treatments achieved 100% mortality across the six genetic strains. The efficacy of hot water treatment (HWT) against phylloxera was investigated by immersing first instars in a water bath set at 22, 40, 45, 50, 60 and 70°C for 60 and 120 s. Treatments of 50°C and above for a minimum of 60 s resulted in 100% mortality across the six genetic strains. Survival was observed at 40 and 45°C, and first instars subsequently established feeding sites, developed into adults and reproduced on excised grapevine roots. Conclusions Steam application and HWT, as currently recommended in the Australian National Phylloxera Management Protocol, are effective for disinfestation of diverse phylloxera strains. Significance of the Study This study has validated, for the first time, the efficacy of steam application and HWT against phylloxera first instars and highlights the potential to lower the recommendations for treatment duration and water temperature disinfestation while still achieving 100% mortality.

The beef feedlot industry in Australia produces a large amount of solid organic by-product each year that is currently applied to agricultural land as a fertiliser supplement. Manure is known to be a valuable source of organic matter and some plant nutrients, especially nitrogen and phosphorus. In addition, manure contains excessive quantities of cations such as sodium (Na) and potassium (K), which may result in long-term sustainability problems for the soil, particularly when large amounts are applied over short time periods. The aim of this study was to determine the effects of composted beef feedlot manure when applied to agricultural soils. Two sites were selected, one a brown Dermosol and the other a red Kurosol, both in north-eastern Victoria near the Rutherglen Research Institute. Both sites received rates of manure up to 109 t/ha in 1996. In 1997 soil samples were collected and compared with untreated control soils. The Dermosol site was sown to an oat and clover mixture in 1996 and 1997 and the red Kurosol was sown to lupin in 1996 and wheat in 1997. The application of composted bovine manure resulted in a 1% increase in soil organic carbon, an increase in soil pH by 1.5 units, increased levels of magnesium, calcium, nitrogen and K in the surface 10 cm soil layer at both sites and an increase in extractable phosphorus levels in the subsoil. There was no detectable increase in surface Na, although there was a small but significant decrease in Na in the 40–80 cm soil layer. It is suggested that soluble organic compounds, migrating down through the soil profile are able to complex with Na and effectively remove some of this cation from the exchange sites of the clay surfaces. In addition, the high porosity of these soils coupled with the high degree of Na mobility ensures that most of this cation is transported deeper into the soil profile. The beneficial effects of applying composted manure are promising as a means of reducing sodicity although these results will require further validation. In addition, the long-term effects of saturating subsurface soil with Na are also a cause for concern and need to be further investigated.

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Background and Aims Grape phylloxera, Daktulosphaira vitifoliae Fitch, is an important biosecurity pest in Australia. As part of a management strategy, movement of grapevine cuttings, rootlings and propagation material must comply with the National Phylloxera Management Protocols which recommend a hot water treatment. This study validated the effectiveness of the protocol against genetically diverse phylloxera strains and developmental stages. Methods and Results Excised roots of Vitis vinifera L. infested with first instars of phylloxera G1, G4, G7, G19, G20 and G30 genetic strains, and eggs, intermediates and adult stages of G4 were immersed in water for 5 and 30 min at 22, 40, 45, 50 and 54°C. Treatments of 45°C for 30 min and >50°C for a minimum of 5 min resulted in 100% mortality of first instars across all six genetic strains as well as eggs, intermediates and adults of phylloxera G4 strain. Insects survived at 22 and 40°C when immersed for 5 and 30 min and 45°C for 5 min and subsequently developed into egg laying adults. Conclusions Hot water immersion for grapevine root material, as currently recommended in the National Phylloxera Management Protocols is effective for disinfestation of genetically diverse phylloxera and developmental stages. A lower temperature treatment of 45°C for 30 min was 100% effective across diverse strains and developmental stages. Significance of the Study Immersion duration and water temperature are important considerations for effective disinfestation of grapevine material against genetically diverse phylloxera strains and different developmental stages.