Lime-induced Chlorosis Research Articles

Integrating GIS and irrigation water quality index approaches for identifying groundwater irrigation potential zones in Central Gujarat, India.

In this study, groundwater irrigation potential zones are identified by measuring an integrated irrigation water quality index using a GIS platform in the Vishwamitri River Basin (VRB) region, Gujarat, India. Classification of different irrigation potential zones is about the collective paraphernalia of thematic maps, namely, electrical conductivity (EC), sodium adsorption ratio (SAR), Na+, Cl-, and HCO3-, which principally regulate the groundwater quality for irrigation. The EC, SAR, and chloride values are > 3000 µS/cm, > 9meq/L, and > 10meq/L, respectively, indicating 98.78%, 41.78%, and 84.88% of the total area, respectively, belong to groundwater both hazardous and unsuitable for irrigation. Similarly, 39.55% of the total area is unsuitable for irrigation due to its high Na+ concentration. The permeability, porosity, and infiltration risk usually appear when excessive sodium ions reduce the rate of flow of irrigation water which moves in the lower soil zones. Similarly, high bicarbonate and chloride concentrations have been denoted to hamper the development of several crops causing symptoms analogous to lime-induced chlorosis due to toxic effects of the salt. The final irrigation potential map is marked by four levels, such as "most suitable," "moderately suitable," "moderately unsuitable," and "unsuitable for irrigation." Approximately, 56.69% of the total VRB region are covered with unsuitable for irrigation purposes. In such areas, irrigation must be avoided in usual conditions, and the halophytes, namely, Khati palak (Atriplex stocksii), Lamb's quarters (Chenopodium album), and Rudravanti (Cressa cretica) should be recommended with high soil permeability and proper drainage facilities. The soil must be highly permeable for groundwaters with high salinity and sodicity. Based on this study, policymakers and environmental managers can estimate the resource implications for drinking and irrigation.

Regreening properties of the soil slow-mobile H2bpcd/Fe3+ complex: Steps forward to the development of a new environmentally friendly Fe fertilizer.

The application of synthetic Fe-chelates stands for the most established agronomical practice to alleviate lime-induced chlorosis, which still constitutes a major agronomic problem. However, the percolation through the soil profile due to the negative charge of the most deployed molecules results in agronomical and environmental problems. H2bpcd/Fe3+ complex features distinctive chemical characteristics, including moderate stability of the Fe(bpcd)+ species (logβML = 20.86) and a total positive charge, and we studied its behavior in soil and regreening effects on cucumber plants. Soil column experiments have underlined that H2bpcd/Fe3+ is retained in more amounts than EDDHA/Fe3+. The new ligand was not proven to be toxic for the cucumber and maize seedlings. A concentration of 20 μM H2bpcd/Fe3+ attained regreening of Fe-deficient cucumber plants grown in the hydroponic solution supplied with CaCO3, similar to that shown by EDDHA/Fe3+. Experiments with a 2 μM concentration of 57Fe showed that cucumber roots absorbed H2bpcd/57Fe3+ at a slower rate than EDTA/57Fe3+. The high kinetic inertness of H2bpcd/Fe3+ may explain such behavior.

Rhizosphere Acidification as the Main Trait Characterizing the Differential In Vitro Tolerance to Iron Chlorosis in Interspecific Pyrus Hybrids

Physiological responses of different interspecific Pyrus hybrids and an open pollinated Pyrus communis ‘Williams’ (Pcw) grown under in vitro culture conditions simulating lime induced chlorosis were studied. The hybrids were derived from crosses between the ‘Pyriam’ pear rootstock and four Pyrus species of the Mediterranean region, namely P. amygdaliformis Vill. (Pa), P. amygdaliformis persica Bornme. (Pap), P. communis cordata (Desv.) Hook. (Pcc), and P. elaeagrifolia Pall (Pe), all known for their higher field tolerance to iron-chlorosis than P. communis. Twenty hybrids and one open pollinated Pcw were micropropagated, and plantlets were in vitro characterized for their physiological responses to iron-deficiency conditions. Rooted plantlets were transferred to a culture medium with 2 µM Fe3+ DTPA and 10 or 20 mM NaHCO3. These physiological responses were scored at 1, 3, 7, and 28 days from the start of the in vitro assay. Leaf total chlorophyll content, the capacity of roots to acidify the medium, reduced iron, and exudates of phenolic acids and organic acids were analyzed in each media and time sample. Leaf chlorophyll levels for the clones derived from Pcc were the highest, especially under the highest bicarbonate concentration, followed by those derived from Pap and Pa. The higher chlorophyll content of Pcc clones were related with their higher capacity to acidify the media but not with their iron reduction capacity at the root level. On the other hand, hybrid clones derived from Pe showed a higher Fe3+ reduction ability than clones from all the other species during the whole assay but only when the bicarbonate concentration was lower. The exudation of phenolic acids by the roots was higher in Pcw than in the other species, and this response might explain why the total chlorophyll levels in Pcw clones are similar to those of Pe and Pa ones. These results with Pyrus spp. bring more evidence in support of the idea that iron reduction capacity at the root level is not directly related with a higher tolerance to iron deficiency caused by the high pH of calcareous soils. Instead, the ability to acidify the rhizosphere is the trait of choice for the selection of the pear hybrid clones better adapted to lime induced chlorosis. In addition, the in vitro assay to select the Pyrus clones for tolerance to iron chlorosis could be shortened to one week of culture in 10 mM NaHCO3, measuring the leaf chlorophyll level, acidification of the culture medium, and exudation of phenolic acids as the physiological responses to predict tolerance to lime-induced chlorosis.

Selection of Tolerant of Some Citrus Hybrids F1 to Calcareous Stress and Identification Sexuall Individuals by SSR Marker

The research was conducted during two seasons 2018-2019 and 2019-2020, at the Scientific Research Center in Lattakia-Syria, where the cross between Sour orange, Cleopatra mandarin and Trifoliate orange. The first season was (Sour orange ♂ × Cleopatra mandarin ♀) and (Cleopatra mandarin ♂ × sour orange ♀) and (sour orange ♂ × trifoliate orange ♀), and the crossing in the second season was (Trifoliate orange ♂ × Sour orange ♀), and (Trifoliate orange ♂ × Cleopatra mandarin ♀). The plants of the first generation F1 were exposed to calcareous stress according to two methods. The first one for a long term (two years) method was grown in plots containing 15% and 35% Calcium Carbonate and the control free of Calcium Carbonate for the first cross, and the second one short term (two months) by watering method was with a solution of 1 mol and 2 mol of Calcium Carbonate for the second cross. The indicators of proline and chlorophyll A, B and T were measured in the first-generation individuals, once at the beginning of the experiment and a second time at the end of study. Seven SSR primers were used to identify sexual individuals, five primers were able to identify sexual F1 individuals are CSM13, CSM17, CSM147, CSM18 and TAA27, F1 individuals in the first season (mixture experiment) gave high values of chlorophyll and were tolerant to calcareous stress from crossing Cleopatra mandarin and Sour orange, where they did not show a deterioration in chlorophyll, but rather increased chlorophyll values, and the Trifoliate orange hybrids were sensitive to this stress, and in the watering experiment the F1 showed significant deterioration in Chlorophyll in all seedlings, and symptoms of Lime-induced chlorosis appeared on the more sensitive seedlings.

Nutrients Assimilation and Chlorophyll Contents for Different Grapevine Varieties in Calcareous Soils in the Somontano DO (Spain)

Lime-induced chlorosis (LIC) is an important abiotic constraint affecting the growth and yield of grapevines growing in calcareous soils in the Mediterranean region, and the sensory properties of the produced wine. In the work presented herein, the impact of LIC on the nutritional status and chlorophyll content was assessed for eleven varieties and a clone (Merlot, Pinot Noir, Cabernet Sauvignon, Tempranillo, Parraleta, Moristel, Aglianico, Macabeo, Sauvignon, Chardonnay, and Riesling), grafted to the same rootstock (1103 Paulsen). Macro- and micronutrient contents were determined in the fruit set and veraison stages by petiole analyses, while chlorophyll content in young leaves was monitored by SPAD. Significant differences were detected amongst varieties for all nutrients (including Fe), and inverse relationships between Fe and P contents in the petiole and chlorophyll concentration in the young leaves were found. Regarding LIC resistance, the Fe and chlorophyll contents suggest that Cabernet Sauvignon, Tempranillo and Aglianico varieties would show the best performance, while Sauvignon would be the least tolerant.

Investigation of responses of some apple (Mallus x domestica Borkh.) cultivars grafted on MM106 and M9 rootstocks to lime-induced chlorosis and oxidative stress

The response of dwarf (M9) and semi dwarf (MM106) clonal apple rootstocks and 5 apple cultivars [Granny Smith (GS), Fuji (F), Royal Gala (RG), Mondial Gala (MG) and Red Chief (RC)] grafted on these rootstocks to lime induced iron chlorosis and iron deficiency induced oxidative stress were investigated. Both rootstocks and cultivars were divided into two groups. One of the group were kept as control group. To the second group, to ensure the lime-induced chlorosis, bicarbonate (HCO3−) was applied. Both groups were grown for two years in a pot experiment. The soil used in the experiment was a clay loam calcareous soil containing 70.9gkg−1 lime. To evaluate the lime-induced chlorosis effects on both rootstocks and cultivars, accumulation of H2O2 and membrane damage (MDA, lipid peroxidation), activities of catalase (CAT, EC 1.11.1.6), superoxide dismutase (SOD, EC 1.15.1.1) and ascorbate peroxidase (APX, EC 1.11.1.11) determined. Bicarbonate treatment reduced active and total Fe and total chlorophyll concentrations, and FCR (leaf ferric chelate reductase) activity while increased the MDA, H2O2, SOD and APX activity of cultivars and rootstocks in both years. These changes and the statistical significances of individual and combined effects of treatment and cultivar or rootstocks showed great differences among the cultivars and rootstocks. So B/C rates helped us to evaluate the tolerance to lime induced chlorosis of the cultivars and rootstocks. B/C referring Fe efficiency ratio calculated as the value for the bicarbonate treatment divided by that for the control for each parameter studied used for tolerance state of cultivars and rootstocks. According to B/C ratios calculated for active and total Fe, FCR, the MG and RG grafted on both rootstocks regarded as tolerant cultivars. In addition to this, the MM106 rootstock was more tolerant than the M9 rootstock under bicarbonate applied condition giving higher B/C ratio for active and total Fe, total chlorophyll, FCR and APX but lower MDA concentrations. It can be concluded that suitable cultivar-rootstock combinations is a good strategy to overcome Fe chlorosis in apple plants grown in calcareous soils.

Response of ungrafted rootstocks and rootstocks grafted with wine grape varieties (Vitis sp.) to ‘lime-induced chlorosis’

ABSTRACTThe ungrafted rootstocks 41B, 1103P, 110R and 140Ru, the grafted combinations of 41B, 1103P and 110R with Xinomavro (one of the most important red wine grape varieties in Greece), as well as those of 1103P, 110R and 140Ru with Chardonnay, were evaluated for 'lime-induced chlorosis' tolerance by growing them with a) basic nutrient solution (BNS), b) BNS + 10 mM bicarbonate, c) BNS without iron (Fe) and d) BNS without zinc (Zn), in hydroponics. The ungrafted 140Ru followed by 41B under high bicarbonate presented the lowest degree of chlorosis; however only 41B presented non-differentiated biomass production and root/shoot ratio. Chlorotic symptoms in combination with plant growth parameters should be used as a tool for grapevine rootstock lime-tolerance screening whereas leaf Fe concentration and root ferric chelate reductase (FCR) activity should not. Lime-stress conditions affected plant mineral nutrition by depressing leaf nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg) and increasing potassium (K), and zinc (Zn).

Lime-induced chlorosis of grapevine as affected by rootstock and root infection with arbuscular mycorrhiza and Pseudomonas fluorescens

Grapevine cuttings ( Vitis vinifera L. cv. Pinot blanc, clone VCR 5), grafted on 3309 C, a lime-susceptible rootstock, SO 4, a medium lime-tolerant rootstock and 41 B, a lime-tolerant rootstock, were grown in pots containing unsterilized calcareous soil. Before potting, the roots of the grafted plants were inoculated with a suspension of a mutant of Pseudomonas fluorescens and with the vesicular-arbuscular mycorrhizal (VAM! fungus Glomus mosseae (Nicol. & Gerd.) Gerd. & Trappe, in order to investigate the effect of these microorganisms on the severity of lime-induced chlorosis. The most significant findings were: Pseudomonas fluorescens and Glomus mosseae treatments increased Fe and chlorophyll concentrations in the leaves and thus lime tolerance in plants grafted on 3309 C and 41 B; the positive effect of VAM treatment was associated with increased levels of root infection and lower root growth; the bacterial treatment improved the establishment of VAM fungi; fruit quality of the susceptible graft combination raised to the level of untreated Pinot blanc/SO 4 vines due to the root treatments.

Humic Acid–Like Substances Extracted from Compost Improve Fe Nutrition of Lemon Grown on Calcareous Soil: An Environmentally Safe Approach

The short-term effectiveness of soil-applied humic acid–like substances [naturally complexed or uncomplexed with iron (Fe)] extracted from composted poultry (HLSP) and sheep (HLSS) manures in preventing lime-induced Fe chlorosis in Eureka lemon (Citrus lemon L.) cuttings grafted on sour orange (Citrus aurantium L.) was investigated and compared with the commonly applied ethylenediamine di-2-hydroxyphenyl acetate ferric (FeEDDHA). Treatments were untreated plants and plants fertilized with FeEDDHA, HLSP, and HLSS injected into the soil at a total rate of 25 mg Fe per plant each. Chlorophyll concentration index (CCI) of the youngest fully expanded leaves, growth vigor, and leaf Fe concentration were measured. HLSP and HLSS, similar to FeEDDHA, resulted in significantly greater CCI values, growth vigor, and leaf Fe concentration compared to untreated plants. HLSP and HLSS offer potential alternative to FeEDDHA to prevent lime-induced Fe deficiency in Eureka lemon. Concentrates of HLSP and HLSS can be commercially prepared to offer an inexpensive and environmentally safe product.

Předběžné výsledky hodnocení rezistence podnoží pro révu vinnou k chloróze vyvolané vápníkem

Resistance to lime-induced chlorosis is very important characteristic of grapevine rootstocks. Lime-induced chlorosis influence yield and quality of grapes. Evaluation of chlorosis resistance is very important for grape growing and breeding. The aim of this work is provide results of evaluation grapevine rootstocks to chlorosis. High resistance was show in Fercal. From the viewpoint of the resistance to chlorosis, the rootstocks registered in the State Variety Book of the Czech Republic can be ranked from the most resistant to the most sensitive as follows: Craciunel 2 – SO 4 – Kober 125 AA – Kober 5 BB – Teleki 5 C – Amos – LE-K-1.

Iron efficiency of different corn hybrids grown in nutrient solution culture

Growing Fe-efficient genotype(s) could be considered as a preferred genetic approach to tackle the widespread constraint of Fe-deficiency-/lime-induced chlorosis in crop grown on alkaline soil. This study aimed to investigate morphological and physiological traits linked to expression of Fe deficiency among four corn (Zea mays) including sweet (Z. mays sacchrata cvs. H403 and H404) and grain (Z. mays indentata cvs. H500 and H700) hybrids grown in nutrient solution using two Fe concentrations (5 and 50 µM Fe-ethylenediaminetetraacetic acid (Fe-EDTA)). Significant variation was found among studied hybrids in their tolerance to Fe-deficiency stress. Sweet corn hybrids were more sensitive to Fe deficiency as compared with grain corn hybrids and greater reduction was observed in their shoot dry matter at the 5 µM Fe-EDTA treatment. The greatest decrease in plant height, leaf area, and root and shoot dry matter weight under Fe-deficiency condition was found for H403 hybrid. No significant correlation was found between shoot and root Fe concentration with crop tolerance to Fe deficiency. Furthermore, different response of corn hybrids to Fe deficiency is an important factor, which has to be considered in Fe fertilizer recommendation as well as breeding programs.

Tolerance k chloróze vyvolané vápnem a k suchu u podnoží pro révu vinnou

Due to the expansion of phylloxera into European vineyards rootstocks became an integral part of successful modern growing of grapevine. Breeding of rootstocks and their selection for resistance against both biotic and abiotic factors can be classified as a biotechnology. In this respect, the ca­pa­bi­li­ty of grapevine plants to adapt themselves to pedological conditions, especially to drought and a high content of lime (or factors inducing their chlorosis) represents a very important breeding goal. In this survey possible causes of lime-induced chlorosis and drought damage and their consequences are analysed. Some important drought-and-lime induced chlorosis-related properties of some selected rootstocks are mentioned as well.

Physiological responses to soil lime in wild grapevine (Vitis vinifera ssp. sylvestris)

Lime-induced chlorosis is a widespread nutritional disorder affecting grapevines cultivated in calcareous soils. A greenhouse experiment was conducted to investigate the response of Vitis vinifera ssp. sylvestris to soil lime by evaluating the effects of a range of soil CaCO3 contents (0–60%) on plant growth, nutrient content (iron, potassium, nitrogen and phosphorus) and photosynthetic performance (gas exchange, chlorophyll fluorescence parameters and photosynthetic pigments). The highest soil CaCO3 concentration induced nutrient imbalances and significantly inhibited photosynthetic function, causing a reduction in carbon gain and consequently, a drastic growth reduction and high mortality. However, all the plants survived external CaCO3 contents of up to 40%, and reduction in growth at 20% CaCO3 was slightly lower than that recorded in several previously studied lime-tolerant varieties of grapevine. Plants grown at 20% CaCO3 maintained net photosynthesis values of around 6μmolm−2s−1, a similar chlorophyll content to that of the control plants and dawn Fv/Fm values close to the optimal values for unstressed plants. Up to the 40% CaCO3 treatment, the study species was capable of maintaining Fe uptake by the roots and translocation to leaves, while controlling the nutritional status of N and P. Our study indicates that the studied population of V. vinifera ssp. sylvestris could provide a source of genetic diversity for lime tolerance improvement in grapevine.

Mapping genetic loci for tolerance to lime-induced iron deficiency chlorosis in grapevine rootstocks (Vitis sp.)

Iron is essential to plants for chlorophyll formation as well as for the functioning of various iron-containing enzymes. Iron deficiency chlorosis is a wide-spread disorder of plants, in particular, of those growing on calcareous soils. Among the different ways to control iron deficiency problems for crops, plant material and especially rootstock breeding is a suitable and reliable method, especially for fruit trees and grapes. The aim of the experiment was to characterize the genetic basis of grapevine chlorosis tolerance under lime stress conditions. A segregating population of 138 F1 genotypes issued from an inter-specific cross between Vitis vinifera Cabernet Sauvignon (tolerant) × V. riparia Gloire de Montpellier (sensitive) was developed and phenotyped both as cuttings and as rootstock grafted with Cabernet Sauvignon scions in pots containing non-chlorosing and chlorosing soils. Tolerance was evaluated by chlorosis score, leaf chlorophyll content and growth parameters of the shoots and roots. The experiments were performed in 2001, 2003 and 2006. The plants analysed in 2006 were reassessed in 2007. The most significant findings of the trial were: (a) the soil properties strongly affect plant development, (b) there are differences in tolerance among segregating genotypes when grown as cuttings or as rootstocks on calcareous soil, (c) calcareous conditions induced chlorosis and revealed quantitative trait loci (QTLs) implicated in polygenic control of tolerance, (d) rootstock strongly contributes to lime-induced chlorosis response, and (e) a QTL with strong effect (from 10 to 25 % of the chlorotic symptom variance) was identified on chromosome 13. This QTL colocalized with a QTL for chlorophyll content (R (2) = 22 %) and a major QTL for plant development that explains about 50 % of both aerial and root system biomass variation. These findings were supported by stable results among the different years of experiment. These results open new insights into the genetic control of chlorosis tolerance and could aid the development of iron chlorosis-tolerant rootstocks.

Occurrence and correction of lime-induced chlorosis in petunia plants

The effect of various concentrations and ratios of iron (Fe) and manganese (Mn) chelates on growth, micronutrient uptake and chlorophyll content was investigated in a glasshouse experiment using potted petunia plants. The plants were cultivated in a peat substrate amended with dolomitic limestone at rate of 3.0 g/L (control substrate) or 12.0 g/L. The higher rate was established both to restrict the uptake of Fe, Mn and other nutrients and also to test the effectiveness of various Fe and Mn treatments. The plants in all the treatments were fertigated at weekly intervals with a nutrient solution containing macronutrients and micronutrients. Various chelate forms of Fe and Mn were used with the exception of two treatments where these two elements were omitted. The effects of different substrate pH levels (derived from different limestone contents) had a large effect on plant growth, chlorophyll content and content of Fe and Mn accumulated in the plant leaves. The plants in the high-limestone substrate devoid of Fe and Mn had reduced growth and lower chlorophyll content. They also had lower leaf Fe and Mn content than the control plants in the R3 substrate. Regular fertigation with a nutrient solution containing Mn and Fe improved plant growth rate and also increased chlorophyll content. However, its efficiency depended on the chelate form and concentration used. The effect of chelate application on the Fe and Mn leaf content was unclear as it only marginally increased leaf Fe absorption in some treatments. No effect of the various Fe/Mn ratios was observed.

Is Mundulla Yellows really a threat to undisturbed native vegetation? A comment

Summary The term Mundulla Yellows (MY) was coined in 1997 to refer to a dieback disorder involving leaf chlorosis which affects Eucalyptus and other native southern Australian vascular plants. It was thought to be a new, spreading, contagious biotic disease with the potential to devastate native vegetation. Since then, research has found no evidence to confirm any role of biotic agents and generally the disorder has been more convincingly attributed to abiotic soil factors. It has now been suggested that most or all of the reported cases of MY are simply the very well-known nutrient disorder of alkaline soils, lime-induced chlorosis. All of the well-documented records of MY are from sites where acidic soils have become more alkaline because of the use of crushed limestone in road-making or to the use of alkaline irrigation water; none are from undisturbed native vegetation. Despite this research and much circumstantial evidence, the view that MY poses a grave risk to undisturbed vegetation still persists and needs to be corrected accordingly.

Oxidative stress responses and root lignification induced by Fe deficiency conditions in pear and quince genotypes

We analysed Pyrus communis cv. Conference and Cydonia oblonga BA29, differently tolerant to lime-induced chlorosis, to identify the key mechanisms involved in their different performance under Fe deficiency induced by the absence of Fe (-Fe) or by the presence of bicarbonate (+FeBic). Under our experimental conditions, a decrease in root elongation was observed in BA29 under bicarbonate supply. Superoxide dismutase (SOD) and peroxidase (POD) activities were analysed and the relative isoforms were detected by native electrophoresis. The data obtained for both genotypes under -Fe and for BA29 +FeBic suggest the occurrence of overproduction of reactive oxygen species (ROS) and, at the same time, of a scarce capacity to detoxify them. The detection of ROS (O(2)(-) and H(2)O(2)) through histochemical localization supports these results and suggests that they could account for the modifications of mechanical properties of the cell wall during stress adaptation. On the other hand, in the cv. Conference +FeBic, an increase in non-specific POD activity was detected, confirming its higher level of protection in particular against H(2)O(2) accumulation. Peroxidases involved in lignification were assayed and histochemical analysis was performed. The results suggest that only in BA29 under bicarbonate supply can the presence of ROS in root apoplast be correlated with lignin deposits in external layers and in endodermis as a consequence of the shift of PODs towards a lignification role. We suggest that in BA29 the decrease in root growth could impair mineral nutrition, generating susceptibility to calcareous soils. In the cv. Conference, the allocation of new biomass to the root system could improve soil exploration and consequently Fe uptake.

Response of four grapevine (Vitis spp.) genotypes to direct or bicarbonate-induced iron deficiency

In Turkey, calcareous soil conditions usually cause significant decreases in grape yield. Understanding the physiological responses of grapevine genotypes under such conditions would yield invaluable knowledge to recover these problems. This study was thus conducted on the comparative evaluation of the responses of four Vitis spp. materials (a cultivar, 'Alphonse Lavallee', and three rootstocks, 'Fercal', '99 R' and '1613 C'), differing in tolerance potential to direct and lime-induced chlorosis. In greenhouse, rooted cuttings were grown in inert perlite using containers for two years with complete Hoagland nutrients solution except for Fe as variable. The experiment comprised five applications performed for three times per year. Iron applications (FeNaEDTA) in 9 and 36 mg L–1 doses and their combinations with 840 mg L–1 NaHCO3 were compared with control (iron-free Hoagland solution). FeNaEDTA addition into nutrient solution induced significant increases in iron and chlorophyll contents across the genotypes. The highest Fe level was determined in 'Fercal' (169.8 mg kg–1) with 36 mg L–1 FeNaEDTA. Bicarbonate additions restricted the vegetative development of '1613 C'. For instance, iron content of '99 R' was 137.9 mg kg–1 when treated with 9 mg L–1 FeNaEDTA, whereas the iron value reduced to 73.9 mg kg–1 when NaHCO3 was added. 'Alphonse Lavallée' and 'Fercal' displayed their lime-tolerances by exhibiting little reduction of both iron and chlorophyll contents. Therefore, 'Fercal' would be proven as a favorable rootstock for regions with calcareous soil. Tolerance to NaHCO3-induced Fe shortage appeared to be genotype-dependent. Chlorophyll content of young leaves positively correlated with Fe concentration, indicating the vital role of iron in chlorophyll content of leaves.

Effects of Traditional and New Methods on Overcoming Lime-Induced Chlorosis of Grapevine

<i>Vitis vinifera</i> L. cv. Merlot clone R3 grafted on the hybrid <i>Vitis riparia</i> x <i>Vitis rupestris</i> 3309C rootstock was grown in pots containing either calcareous or noncalcareous soil. Three treatments were applied to the plants growing on the calcareous soil: soil application of EDDHA (iron chelate), groundcover with <i>Festuca ovina</i> grass cv. Aurora Gold, and soil application of vivianite (iron phosphate). Shoot growth was recorded and at veraison the chlorosis occurrence and mineral element concentrations of young leaves were analyzed. Grape yield and berry composition were checked at harvest, including soluble solids, titratable acidity, tartaric acid, anthocyanins, polyphenols, and stilbenes. All treatments alleviated chlorosis symptoms over the untreated vines growing on calcareous soil. Grape yield and soluble solids were not affected by the treatments, while acidity, anthocyanins, and polyphenols evolved differently according to treatment. <i>trans</i>-Resveratrol concentration was reduced by all treatments. The floor management with <i>Festuca ovina</i> seems to be an effective, sustainable method to overcome lime-induced chlorosis, as compared with chelate and vivianite application.

Pear plantlets cultured ‘in vitro’ under lime-induced chlorosis display a better adaptive strategy than quince plantlets

In many fruit trees species lime-induced chlorosis causes serious economic damage. In the last few years, the in vitro culture technique has been applied to test rootstocks for susceptibility to iron chlorosis and to study biochemical and molecular aspects of the syndrome. In this study in vitro shoot cultivation of quince rootstocks MA, BA29 and pear cv. 'Conference' was used to unravel the relationship between iron deficiency, presence of bicarbonate, and growth development and chloroplast pigment behav- iour. Stresses were obtained by using MS medium supplemented with various concentrations of FeNa- EDTA and/or KHCO3. Substrate pH, shoot growth and development parameters, total leaf iron and photosynthetic pigment contents of plantlets were independently determined after 24 days of culture. The medium was acidified by the species under all stress conditions. Iron deficiency and bicarbonate condition led to different growth patterns and mod- ular development among the genotypes. This reflects a different sensitivity and plastic adaptation to the elements of this stress. Iron concentration in leaves and the shoot apex of plantlets decreased in all genotypes. However, chloroplast pigments only decreased in quince plantlets under iron deficiency and bicarbonate condition while they did not change in pear plantlets. Our results demonstrate firstly that a plantlet without a root system, which is cultivated in vitro, is able to sense iron deficiency and bicarbonate enriched conditions and, consequently, activates biochemical and physiological responses. Secondly, acidification appears to be related to iron concentra- tion in tissues of quince rootstocks and pear cultivar. Finally, chloroplast biochemical elements are strongly and differently regulated under both stress conditions and between genotypes.