Effects of salinity on leaf mineral composition and salt injury symptoms of some Iranian wild grapevine ( Vitis vinifera L. ssp. sylvestris) genotypes

摘要

Aim: To evaluate the suitability of wild grapevine genotypes to saline conditions by measuring leaf ion content and salt injury symptoms.Methods and results: Vines of nine wild (Vitis vinifera L. ssp. sylvestris) genotypes were planted in pots and after the good establishment, salinity treatments (0, 50, 100 and 150 mM NaCl) started. At the end of the experimental period, the K+, Na+, NO3- and Cl- content of leaves and visible symptoms of salt injury were recorded. Leaf Na+ and Cl- content increased with increasing salinity but levels and accumulation rates were different among genotypes.Conclusion: Based on Na+ and Cl- content and salt symptoms, genotypes 4 and 7 showed less symptoms than the other genotypes at moderate (50-100 mM) NaCl concentration and none could tolerate high salt (150 mM) concentration.Significance and impact of the study: Under saline conditions, ion accumulation in the leaves significantly varied among wild genotypes and some of them could be recommended as saline tolerant genotypes. IntroductionAccumulation of Cl- and Na+ in grapevines in saline condition may result in physiological disturbances leading to reductions in growth, vegetative biomass, and fruit yield (Walker et al., 2010). The specific ion toxicity occurs when the vines accumulate certain ions at levels above those known to cause detrimental effects. Grapevines are considered moderately sensitive to root-zone salinity and it has long been known that variation in salt tolerance exists between grapevine species and cultivars (Fisarakis et al., 2001). Several studies revealed that salt tolerance mechanisms in grapevine involve many factors like restriction of ion absorption, translocation from roots to shoots, photosynthesis alteration and solute accumulation (Shani and Ben-Gal, 2005; Walker et al., 2010). Some of the grapevine rootstocks have been rated as tolerant to salinity due to their ability to prevent Na+ and/or Cl- uptake and translocation to aerial parts of the vines (Tregeagle et al., 2006). When used as a grapevine rootstock, 140 Ruggeri (Vitis berlandieri × Vitis rupestris) is known to be a good Cl- excluder, whereas K 51-40 (Vitis champinii × Vitis riparia 'Gloire') is a poor excluder and scions grafted to it accumulate high concentrations of Cl- when grown under saline conditions (Walker et al., 2010). One of the strategies adopted in overcoming salinity is the use of tolerant genotypes through the characterization of local genetic resources and the selection of potential tolerant genotypes (Fisarakis et al., 2001). In Iran, wild grapevine (Vitis vinifera ssp. sylvestris) populations are generally found in riparian woodland habitats in the Alborz and Zagros Mountains in the north and north-west of the country (Doulati Baneh et al., 2011). The availability of these genotypes provides an excellent opportunity to determine their suitability to saline conditions. So the aim of this study was to evaluate the tolerance of nine wild grapevine genotypes to salt stress, with an emphasis on ion (Na+, K+, Cl-, NO3-) accumulation and interaction in leaves.Materials and methodsVines of nine wild grapevine genotypes were planted in pots containing a mixture of soil (fine loamy, super active, mixed, mesic typic calcixerepts) and sand (1:1 v/v). They were grown for 40 days and after good plant establishment (8 cm green shoot growth, 5 young leaves), salinity treatments started. The experimental design was a Factorial Complete Randomized Block design with two factors (salinity at 0, 50, 100 and 150 mM NaCl and genotype including 9 wild grapevines). This experiment was carried out at the Agricultural and Natural Resource Research Center of West Azerbaijan-Iran. At the end of the experimental period, the concentration of K+, Na+, NO3- and Cl- in leaves was measured and visible symptoms of salt injury in vines scored as: 1- plants with no necrotic tissues; 2- necrosis on 30% of blade and on the tip of the leaves; 3- necrosis on 50% of the leaves and on the stem; 4- necrosis on 60-80% of the leaves and on the stem; and 5- necrosis leading to the death of the plant. Analysis of variance (two way ANOVA) was done using SAS 9.1 software and differences among means were compared by Duncan’s Multiple Range Test at PPTable 1. Analysis of variance on different characters affected by salinity and genotype.View popupExpand inlineCollapse inlineS.O.Vd.fMeans of SquareaNa+K+Cl-NO3-Salt InjuryBlock230.932.2345.132.220.07**Salinity (S)31006.00**12.47**1658.75**161.97**7.73**Genotype (G)842.47**1.54**67.11**61.66**0.32**S×G2410.24**0.82**14.63**12.04**0.10**Error703.010.353.232.540.02C.V (%)7.0710.346.5113.168.62S.O.V., Source of variance; d.f., degree of freedom; ** Significant differences at P≤ 0.01; a. Table 2. Percentage of Explained Variance.View popupExpand inlineCollapse inlineS.O.VPercentage of Explained Variance (PEV)Na+K+Cl-???? NO3-Salt InjurySalinity (S)77.83880.516.178.1Genotype (G)8.712.58.742.98.6S×G6.3205.6825.18S.O.V., Source