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Background and Aims Rooted leaves were used to analyse the salt exclusion phenotype in grapevines. Genotypes included rootstocks 140 Ruggeri and K51‐40 and cultivar Cabernet Sauvignon – respectively, good, poor and intermediate chloride excluders. Methods and Results We investigated the effect of short‐term salt treatment on the chloride, sodium and potassium concentration of organs and whole rooted leaves and the time course of chloride accumulation in salt‐treated, whole rooted leaves. The effect of Control and salt plus low and high nitrate concentration on chloride and nitrate concentration in organs was assessed. Salt treatment increased chloride and sodium concentration in all organs but had no effect on potassium concentration. The chloride concentration of whole rooted leaves and the sodium concentration of lamina and petiole were similar between salt‐treated rooted leaves of 140 Ruggeri and K51‐40; 140 Ruggeri accumulated more chloride in roots and less in leaf (petiole and lamina) than K51‐40. Roots of salt‐treated 140 Ruggeri and K51‐40 responded to higher external nitrate by decreasing chloride concentration and increasing nitrate concentration. Conclusions Restricted transport of chloride to the leaf and greater storage in roots is a feature of the chloride exclusion phenotype in rooted leaves. The short‐term capacity of 140 Ruggeri for chloride exclusion from the leaf was reduced in the salt plus high nitrate treatment. This was linked to higher nitrate and reduced chloride accumulation in roots. Significance of the Study The chloride exclusion phenotype in rooted leaves was shown to involve greater partitioning to roots and less to the leaf, rather than differences in net chloride accumulation by whole rooted leaves.

Background and Aims The effect of rootstock on chloride (Cl−) and sodium (Na+) exclusion capacity and yield of Chardonnay and Shiraz was investigated in the final 2 years (2007/08 and 2008/09) of a long-term (14-year) saline irrigation trial. Methods and Results Chardonnay and Shiraz, on own roots and on nine rootstocks, were irrigated for the first 12 seasons with water of electrical conductivity (ECiw) of 2.1 dS/m, with 7.15 ML/ha the mean total applied. The final two seasons were years of water restrictions, where the vines were irrigated with water of (mean) ECiw of 1.65 dS/m at a seasonal application of 3.04 ML/ha. Vines on own roots had a relatively low yield, for example 2.0 kg/vine (Chardonnay) and 8.8 kg/vine (Shiraz), and a high concentration of both chloride and sodium in grape juice (>1000 mg/L for Chardonnay and >500 mg/L for Shiraz). Ramsey and 1103 Paulsen rootstocks produced a high yield of 11–12 kg/vine with Chardonnay, and Ramsey and C7 produced a high yield of 23.5–24.5 kg/vine with Shiraz. Chardonnay on C5 and Shiraz on C7 rootstocks had the lowest concentration of grape juice chloride and sodium (in each case 10 years) study to compare the effect of rootstocks on the tolerance of Chardonnay and Shiraz to salinity.

Potted grapevines of 140 Ruggeri (Vitis berlandieri × Vitis rupestris), a good Cl(-) excluder, and K 51-40 (Vitis champinii × Vitis riparia 'Gloire'), a poor Cl(-) excluder, and of a family obtained by crossing the two genotypes, were used to examine the inheritance of Cl(-) exclusion. Rooted leaves were then used to further investigate the mechanism for Cl(-) exclusion in 140 Ruggeri. In both a potting mix trial (plants watered with 50 mM Cl(-)) and a solution culture trial (plants grown in 25 mM Cl(-)), the variation in Cl(-) accumulation was continuous, indicating multiple rather than single gene control for Cl(-) exclusion between hybrids within the family. Upper limits of 42% and 35% of the phenotypic variation in Cl(-) concentration could be attributed to heritable sources in the potting mix and solution culture trials, respectively. Chloride transport in roots of rooted leaves of both genotypes appeared to be via the symplastic pathway, since addition of 8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS), an apoplastic tracer, revealed no obvious PTS fluorescence in the laminae of either genotype, despite significant accumulation of Cl(-) in laminae of K 51-40 during the PTS uptake period. There was no significant difference in either unidirectional (36)Cl(-) flux (10 min) or (36)Cl(-) uptake (3 h) into roots of rooted leaves exposed to 5, 10, or 25 mM Cl(-). However, the percentage of (36)Cl(-) transported to the lamina (3 h) was significantly lower in 140 Ruggeri than in K 51-40, supporting reduced Cl(-) loading into xylem and implicating the root stele in the Cl(-) exclusion mechanism.

Background and Aims: Within-site comparisons were made of rootstock effects on yield, and chloride and sodium concentrations in petioles, juice and wine of Shiraz and Chardonnay vines at sites with irrigation water salinities (ECiw) ranging from low (0.4 dS/m) to moderate-high (1.8 to 3.3 dS/m). It also compared consistency of yield performance of the various rootstocks with both scions over 8 years at one site with an ECiw of 2.1 dS/m. Methods and Results: Chardonnay and Shiraz on own roots and on Ramsey, 1103 Paulsen, 140 Ruggeri, K51-40, Schwarzmann, 101-14, Rupestris St. George and 1202 Couderc were compared. Ramsey resulted in better yields relative to most of the other rootstocks at three of the four sites for each scion. Exceptions were the low salinity site where Schwarzmann was best with Chardonnay, and Padthaway where 140 Ruggeri was best with Shiraz. Chardonnay wine chloride concentrations were similar to grape juice chloride concentrations, but Shiraz wine chloride concentrations were on average 1.7-fold higher than grape juice chloride. Conclusions: Shiraz on own roots, K51-40 and 1202C rootstocks carry some risk of accumulating unacceptable levels of chloride in grape juice and wine when the salinity of the irrigation water is at moderate to high levels. Rootstocks K51-40 (with Chardonnay and Shiraz) and potentially 101-14 (with Shiraz) should be avoided in situations of long term irrigation with moderate to high salinity water. Significance of the Study: The study identifies rootstocks with acceptable yields and grape juice chloride concentrations for potential use in regions affected by salinity.

Background and Aims: Rootstocks influence the inorganic ion and organic acid composition of grapes of the scion variety. The aim was to investigate the impact of rootstocks on the inter-relationship of inorganic ions and organic acid anions in the skin and pulp of grapes and in resultant wine. Methods and Results: Vines were irrigated with water having electrical conductivities in the range 1.6–2.1 dS/m. Chloride, sodium, potassium, malic and tartaric acid concentrations were higher in almost all cases in skin than in pulp. Significant positive correlations existed between chloride and sodium concentrations in both pulp and skin. A significant negative linear regression existed between malic acid and both chloride and sodium concentrations in skin of Chardonnay berries. There were positive linear regressions in chloride concentration between berry (pulp and skin) and resultant wine chloride in both Chardonnay and Shiraz. Conclusion: The higher malic acid and lower chloride concentrations in skin of most grafted Chardonnay and Shiraz vines, and vice versa for own rooted vines, may indicate competition for similar transporter proteins involved in loading into skins. Alternatively, higher salt concentrations in skins may be associated with accelerated malic acid catabolism. Significance of the Study: Chloride-excluding rootstocks demonstrated advantages through reduced chloride (but not sodium) in pulp and skin of grape berries and in resultant wines. Where rootstocks reduced chloride concentrations in skin of grape berries, there is potential for higher malic acid in skin and in the resultant red wines.

Shiraz and Chardonnay grapevines that had been initially assessed for Cl- exclusion in the 1996 and 1997 harvest seasons at both Merbein (inland region of Victoria) and at Padthaway (sub-coastal region of South Australia), were re-evaluated in 2003 and 2004 at those same two locations. Both scion varieties were grown either on their own roots or were grafted to one of the following rootstocks: Ramsey, 1103 Paulsen, 140 Ruggeri, K51-40, Schwarzmann, 101-14, Rupestris St George and 1202 Couderc. Both sites had been irrigated with saline water since 1994. The salinity of irrigation water at Merbein was approximately 2.1 dS/m; at Padthaway irrigation salinity varied between approximately 1.6 dS/m and 2.5 dS/m during the survey period. Changes in the Cl--excluding ability of all rootstock/scion combinations between 1996, 1997 and 2003, 2004 were based upon analysis of Cl- concentrations in grape juice and in laminae at harvest, as well as Electrical Conductivity (EC), pH and Sodium Adsorption Ratio (SAR) of the 1:5 soil:water extract. Taking juice Cl- as indicative of rootstock effectiveness for Cl- exclusion, and considering data from Merbein, our analyses demonstrated that overall means for Shiraz juice Cl- increased from around 190 to 427 mg/L over the survey period (7 years). In Chardonnay grapevines at Merbein, overall mean concentrations of Cl- in juice increased from around 70 to around 225 mg/L over 7 years. Significant differences between rootstocks were evident, with some rootstocks at Merbein showing a diminished capacity for Cl- exclusion in 2003 and 2004. By contrast, in Padthaway there was no consistent deterioration in Cl--excluding capacity by rootstocks supporting either Shiraz or Chardonnay as scions. In 2004 there were significant differences between grapevines at Merbein and Padthaway in the concentration of Cl- accumulated, even though the mean soil EC1:5 after harvest for 0–90 cm depth was the same at both sites, namely 0.4 dS/m. Containment of grapevine salinity at Padthaway (relative to Merbein) between 1996/97 and 2003/04 was most likely due to factors such as a lower volume of saline irrigation, double the rainfall and 27% lower pan evaporation.

Field vines of cv. Sultana, grown either on their own roots, or grafted to a range of rootstocks, were drip-irrigated at three salinity levels (0.40, 1.75 and 3.50 dS/m) over a five-year period. Rootstocks comprised Ramsey, 1103 Paulsen, J17-69 and 4 hybrids (designated R1, R2, R3 and R4) derived from parentage involving Vitis champini, V. berlandieri and V. vinifera. Concentrations of Cl-, Na+, K+, Ca2+ and Mg2+ were measured in petioles at flowering, and in laminae and grape juice at harvest, in each year of the trial. Vines on all rootstocks accumulated less chloride in either petioles at flowering or in laminae and juice at harvest compared with vines on own roots at all salinity treatments. By inference, all rootstocks behaved as chloride excluders relative to the roots of own-rooted vines. 1103 Paulsen was the best chloride excluder based on lowest concentrations of accumulated Cl- in petioles, laminae and grape juice at high salinity. Sultana on R3 rootstock at high salinity accumulated more Na+ in both laminae and grape juice (at harvest) than did Sultana on own roots or on any of the other rootstocks. Laminae K+ at harvest time was reduced at high salinity in Sultana on own roots and on all rootstocks. Concentrations of both Cl- and Na+ in petioles at flowering and in laminae and grape juice at harvest showed no significant correlation with either yield (as kg of fresh grapes per vine) or vigour (as measured by fresh weight of one-year-old pruning wood per vine) for any salinity treatment. There was however, a strong positive correlation between yield and the subsequent weight of one-year-old pruning wood for all salinity treatments. There was also a negative correlation between Na+ concentrations in petioles at flowering and the subsequent weight of one year-old-pruning wood from the 0.40 dS/m treatment. Similar negative correlations were found between Na+ concentration in both laminae and grape juice at harvest time, and the subsequent weight of one-year-old pruning wood from the 0.40 dS/m treatment (but not from either the 1.75 or 3.50 dS/m treatments). Based on these findings and those from Walker et al. 2002a we conclude that a high innate vigour of a rootstock combined with moderate to high chloride and sodium exclusion ability represents the best combination for salt tolerance in Sultana grapevines as measured by yield at moderate to high salinity.