Uptake Of Mineral Elements Research Articles

Nitric oxide mitigates salt stress effects of pepper seedlings by altering nutrient uptake, enzyme activity and osmolyte accumulation.

This study was planned to evaluate the role of exogenous application of sodium nitroprusside (SNP), a NO donor, on the deleterious effect of salinity in Capsicum annum L. seedlings. Different NO doses (0, 50, 100 and 150µM SNP) were foliarly applied to pepper seedlings grown under the non-saline and saline conditions (50, 100 and 150mM of NaCl). The photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2 concentration (Ci), transpiration rate (Tr), mineral element (Zn, Fe, B, K, Ca and Mg) uptake, plant growth and leaf relative water content (LRWC) weredecreased by NaCl treatment, but NO treatments generally improved the observed parameters. 150mM NaCl treatment caused overaccumulation of hydrogen peroxide (H2O2) and malondialdehyde (MDA) by 87 and 100% respectively as compared to control. However, NO application (150µM SNP) at 150mM of NaCl significantly decreased H2O2 and MDA to 34 and 54%, respectively. The present study clarified that the exogenous NO treatment supported pepper seedlings against salinity stress by regulating the mineral nutrient uptake, antioxidant enzyme activity, osmolyte accumulation, and improving the LRWC and photosynthetic activity.

Mineral elements uptake and physiological response of Amaranthus mangostanus (L.) as affected by biochar

Amaranthus mangostanus L. (amaranth) was hydroponically grown in different concentrations of biochar amended nutrient solution to investigate the mineral elements migration and physiological response of amaranth as affected by biochar. Our results showed that exposure to 26.6 g/L of biochar greatly increased the root and shoot K, Na and Al content, while 2.6 g/L of biochar greatly increased the root Ca and Mg content. The uptake of K and Al notably altered other elements' accumulation in shoots and roots upon the biochar exposure. The ratio of Ca: K in shoots and Mg: K in roots were negatively correlated to the biochar concentrations, while the ratio of Al: Ca and Al: Mg in roots were positively related to the biochar concentrations. The Al: Fe ratio was also polynomial correlated to the concentrations of biochar. The addition of biochar beyond 2.6 g/L resulted in the cell membrane and DNA damages in roots. The activity of SOD and CAT in 6.7 g/L biochar treated roots was significantly elevated as compared to the ones in other biochar treatments and was almost 2-fold of the control. The photosynthetic Fv/Fm intensity and subcellular structure in leaves were also compromised upon exposure to 26.6 g/L biochar. Taken together, biochar could significantly alter the mineral migration in amaranth and physiologically damage in the plants. It is essential to study the effect of biochar within appropriate concentrations on plants prior to wide application in agriculture.

Mineral elements for new shoot development in Xanthoceras sorbifolia new shoots.

To clarify the variable characteristics of mineral elements in the development of Xanthoceras sorbifolia shoots, key nutrient elements influencing the development of various parts were used. Mineral elements (N, P, K, Fe, Mn, Cu, Zn, Ca, Mg, and Na) in different parts of the shoots were measured using Autoanalyzer and atomic absorption spectrometers with new shoots of X. sorbifolia from different growth periods. Distribution regularities and dynamic change trendencies of different mineral elements in different parts of the new shoots of X. sorbifolia were then clarified using a factor analysis and correlation analysis. Results showed that:(1) N, P, K, Cu, Fe, and Zn in the shoots decreased during shoots development, and Ca, Mg, Na, and Mn in the shoots increased. (2) Mineral elements in stem tips close to young leaves was always higher than young leaves. (3) Except on May 7th, N, P, Fe, and Mn in leaves were higher than stems. No significant differences were found for Na among stem tips, stems, and leaves. (4) Contents of Mg, Zn, and Cu in leaves at the early stage of shoot growth were higher than in stems, but at the later growing stage were lower. At the early stage, K and Ca content in stems were higher than in leaves, and at the later stage were lower than in leaves. (5) The factor analysis showed that the contents of P, N, K, Cu, and Fe had important effects on the development of X. sorbifolia shoots. The main mineral elements affecting stem tip development were P, N, and Cu; affecting stem development were P, N, and K; and affecting leaf development were P and Cu. (6) The correlation analysis for uptake and accumlation of mineral elements showed significant positive correlations of N, P, K, Cu, and Zn (PPX. sorbifolia shoots. To ensure a nutritional balance and plant health, additions of P, N, K, Cu, Fe and other necessary mineral elements should be coordinated and reasonably applied as fertilizer, to achieve a rational and standardized fertilization program for X. sorbifolia.

Fruit yellow-shoulder disorder as related to mineral element uptake of tomatoes grown in high temperature

Abstract In order to reduce yellow-shoulder (YS) disorder by regulating nutrient solution in high temperature, effects of potassium (K) and phosphorus (P) supplementation on YS index were investigated. Experiments were conducted in an optimum temperature condition under 20 °C, and in a high temperature condition under 31 °C. Nutrient solution of EC 0.9 dS m−1 (PO4-P 1.5 me L−1, K 3.0 me L−1), EC 0.9 + P (PO4-P 4.6 me L−1, K 3.0 me L−1), EC 0.9 + K (PO4-P 1.5 me L−1, K 5.8 me L−1), and EC 0.9 + P + K (PO4-P 4.6 me L−1, K 5.8 me L−1) were used. Each tomato (Solanum lycopersicum L. ‘CF Momotaro York’) plant was grown in 250 mL pot combining three trusses and high-density planting. Results showed that K uptake amount was significantly higher at EC 0.9 + P + K than at EC 0.9, EC 0.9 + P and EC 0.9 + K. K uptake efficiency was higher at EC 0.9 + P than that at EC 0.9, although the application concentraiton of K were identical in them. YS disorder was more severe in 31°C than 20°C temperatures condition in the case of nearly similar uptake of K per plant. The YS index showed a significantly negative linear correlation with K uptake (R2 = 0.81, P

Effects of zinc and silicon on cadmium toxicity and mineral element translocation in two rice ( Oryza sativa ) genotypes

To investigate the long-term effects of zinc-silicon (Zn-Si) on mineral element translocation from root to shoot of rice under cadmium (Cd) stress, we performed this experiment using two rice genotypes (Xiushui 110 and HIPJ 1) with eight combination treatments of three Si levels (0, 5 and 15 µmol/L Na2SiO3·9H2O), three Zn levels (0, 1 and 10 µmol/L ZnSO4·7H2O) and two Cd levels (0 and 15 µmol/L CdCl2). Data on plant biomass, photosynthesis, antioxidant enzyme activity, lipid peroxidation and mineral element concentrations were analyzed. The combination treatments of Cd (15 µmol/L) and Si (15 µmol/L) or Zn (10 µmol/L) resulted in higher shoot height and root length in both the genotypes as compared with the Cd (15 µmol/L) treatment. Analysis of dry mass showed that the sole Zn alleviation was more effective on biomass increase than the sole Si in both the genotypes. The malondialdehyde (MDA) content in leaf dropped across all alleviation treatments in both the genotypes; Xiushui 110 had higher overall leaf catalase activity than HIPJ 1. The sole Zn and Si and the Zn-Si alleviation treatments reduced Cd translocation factor (TF) from root to shoot in HIPJ 1 but not in Xiushui 110. Analysis of TFs showed that Cd significantly reduced the movement of elements such as Ca, Mn and Mg. Zn alone treatment increased plant growth more than Si alone and Zn-Si treatments. However, Zn-Si treatment was not effective on improving mineral element uptake in Cd stressed plants.

Efficient and flexible uptake system for mineral elements in plants.

Contents Summary 513 I. Introduction 513 II. Efficient uptake system formed by influx and efflux transporters of mineral elements 514 III. Polarity of transporters for mineral elements 515 IV. Regulation of transporters in response to environmental change 515 V. Sensing and signaling pathways regulating the uptake of mineral elements 515 VI. Conclusions and perspectives 516 Acknowledgements 516 References 516 SUMMARY: Mineral elements required for plant growth and development must first be taken up by the roots from soil. Plants have developed an efficient uptake system for the radial transport of mineral elements from soil to central stele through the allocation of various transporters at different root cells. These transporters are regulated at transcriptional, translational and/or post-translational level to cope with the fluctuation of mineral elements in soil. In this insight, we describe an efficient uptake system for mineral elements formed by influx and efflux transporters, regulatory mechanisms and polarity of these transporters, and sensing and signal pathways, in response to spatial and temporal changes of mineral elements in soil. An understanding of the mineral element uptake system in different plant species, and its regulatory network, will contribute to high and safe crop production under varying environments.

Overexpression of a Miscanthus sacchariflorus yellow stripe-like transporter MsYSL1 enhances resistance of Arabidopsis to cadmium by mediating metal ion reallocation

The yellow stripe-like (YSL) family of transporters mediates the uptake, translocation, and distribution of various mineral elements in vivo by transferring metal ions chelated with phytosiderophore or nicotianamine (NA). However, little is known about the roles of the YSL genes against cadmium in planta. In this study, we first cloned and characterized a vital member of the YSL gene family, MsYSL1, from the bioenergy plant Miscanthus sacchariflorus. MsYSL1 localized in the plasma membrane and was widely expressed throughout the whole seedling with the highest expression level in the stem. In addition, its expression in the root was stimulated by excess manganese (Mn), cadmium (Cd), and lead, and a shortage of iron (Fe), zinc (Zn), and copper. Functional complementation in yeast indicated that MsYSL1 showed transport activity for Fe(II)–NA and Zn–NA, but not for Cd–NA. Although they exhibited no significant differences versus the wild type under normal cultivation conditions, MsYSL1-overexpressing Arabidopsis lines displayed a higher resistance to Cd accompanied by longer root lengths, lower Cd, Zn, and Mn levels in roots, and higher Cd, Fe, and Mn translocation ratios under Cd stress. Moreover, genes related to NA synthesis, metal translocation, long-distance transport, and Cd exclusion were highly induced in transgenic lines under Cd stress. Thus, MsYSL1 may be an essential transporter for diverse metal–NAs to participate in the Cd detoxification by mediating the reallocation of other metal ions.

Effects of Foliar Selenite on the Nutrient Components of Turnip (Brassica rapa var. rapa Linn.).

We administered foliar applications of 50, 100, and 200 mg L−1 selenium (Se, selenite) on turnip (Brassica rapa var. rapa Linn.) and detected the changes in the main nutrient components in fleshy roots. Results showed that the foliar application of Se (IV) significantly increased the Se content in turnip, and Se (IV) positively affected the uptake of several mineral elements, including magnesium, phosphorus, iron, zinc, manganese, and copper. Se (IV) treatments also improved the synthesis of protein and multiple amino acids instead of crude fat and total carbohydrate in turnip, indicating that the foliar application of Se (IV) could enhance Se biofortification in turnip and promote its nutritional value. We recommended 50–100 mg L−1 Se treatment for foliar application on turnip based on the daily intake of Se for adults (96–139 μg person−1 day−1) and its favorable effects on the nutrient components of turnip.

Effect of application of exogenous nitric oxide at different critical growth stages in alleviating Fe deficiency chlorosis of peanut growing in calcareous soil

ABSTRACTThis study was to investigate peanut response to application of nitric oxide (NO) at different growth stages and the effects of NO application on peanut yield and quality in calcareous soil. Sodium nitroprusside (SNP, a NO donor) solution was poured into calcareous soil at sowing, seedling, flowering, and podding stages, respectively, or at each aforesaid critical stage. Results showed that NO application increased the content of active Fe and leaf chlorophyll, which improved the photosynthesis of peanut; enhanced the ability of resistance to oxidative stress by decreased the accumulation of O2•−, H2O2, and MDA and increased the activity of antioxidant enzymes. Nitric oxide increased the content of soil available Fe and root FCR activity, which can promote peanut absorb more Fe from the calcareous soil. What's more, peanut plants may pump a large amount of H+ from root cell membrane to consume in neutralization of HCO3−, and decrease the pH in apoplast, cytoplasm, and xylem, finally balance the mineral elements (Fe, Ca, Mg, Zn, and Cu) uptake and distribution. These results indicated that NO could improve peanut growth and development, increase peanut yield and quality. Furthermore, the application of NO at sowing or seedling stage did the most obvious effect on alleviating chlorosis of peanut in calcareous soil.

Effect of demineralization time on the mineral composition and mechanical properties of remineralized dentin.

The aim of this study was to determine whether recovery of mineral levels restored the mechanical properties of dentin subjected to different durations of demineralization. Dentin at the floor of class 1 cavities (n = 12) was demineralized for 1, 2, and 3 weeks. Half the demineralized cavity floor was coated (control side), and a Fuji IX restoration was placed. The remaining half was therefore in contact with the Fuji IX restoration (test side). Simulated dentin tubular fluid was then supplied to each pulp chamber for 6 weeks. After remineralization, the teeth were detached from the system and sectioned. Concentrations of calcium, phosphorus, fluorine, and strontium and mechanical properties (hardness and Young's modulus) of the test and control sides were determined by electron probe microanalysis and nano-indentation, respectively. For remineralized dentin demineralized for 1 week, the substantial uptake of mineral elements restored hardness and Young's modulus at depths of 50 to 200 μm from the lesion front. For longer periods of demineralization (2 and 3 weeks), structural damage to the demineralized dentin was severe and impeded recovery of mechanical properties, despite mineral uptake.

栄養生長期の土壌水分の違いが水稲の生育と養分吸収に及ぼす影響 : 作物の干ばつと養分吸収に関する研究(第3報)

栄養生長期の土壌水分の違いが水稲の生育と養分吸収に及ぼす影響 : 作物の干ばつと養分吸収に関する研究(第3報)

生殖生長期の干ばつが水稲の生育と養分吸収に及ぼす影響 : 作物の干ばつと養分吸収に関する研究(第2報)

生殖生長期の干ばつが水稲の生育と養分吸収に及ぼす影響 : 作物の干ばつと養分吸収に関する研究(第2報)

Uptake and Accumulation of Mineral Elements from Winery and Distillery Effluents by Typha latifolia and Phragmites australis

Mineral element uptake by the macrophytes Typha latifolia (bulrush) and Phragmites australis (common reed) from effluent (waste water) was investigated in a two-year sampling program carried out in constructed wetlands at a winery near Stellenbosch (33°55’S, 18°52’E), and at a distillery near Worcester (33°32’S, 19°13’E) in the Western Cape Province. Factors considered were: season of growth, site (distillery or winery), plant kind, wetland retention time and position in the wetland (inflow, outflow). Effluent nitrogen (N), potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na) concentrations were lower at the outflow than at the inflow at the winery, but not the distillery. Dry mass increases in both macrophytes were greater at the distillery than the winery. The distillery effluent contained higher concentrations of N and K than that from the winery. Tissue N, P, K, Na, Ca, Mg, copper (Cu) and zinc (Zn) concentrations were higher in plants at the distillery than at the winery. Tissue N and K concentrations were, respectively, higher and lower in P. australis than in T. latifolia. Retention time, and position within the wetland, had either no, or inconsistent, effects on tissue element concentrations. The total element contents of the macrophytes were small in relation to the quantities of elements in the effluent. Where differences in effluent composition across the winery wetland were observed, these were probably due to biological activity in the effluent itself, on the limestone gravel surfaces, or on the plant roots.

Cultivar and rootstock interaction affects the physiology and fruit quality of table grape with different water management – preliminary results

Vine rootstocks are known to have an influence on the vegetative growth and yield of the scion, and also can influence fruit quality in grafted vines with direct effects on the uptake of water and mineral elements, or more indirectly by affecting the balance between fruit and shoot growth. The adaptability of rootstocks to restrictive soil conditions, water and nutrient supply is variable. The impact of different rootstocks on vine performance and scion could be useful information for selecting which rootstock is more suitable for the soils with reduced water availability. This study was conducted in 2013 on three Vitis vinifera L. cultivars ('Summer Royal', 'Crimson seedless' and 'Autumn Royal') grown in Apulia region (southern Italy) and planted in the same trial site. All vines were grafted onto two rootstocks ('140 Ru' and '34 EM') and subjected to two different irrigation practices under controlled water deficit, in order to study the effect of grafting and water deficit on the whole vine growth and productive development. In particular, vine performance was assessed throughout the season by determining the leaf water potential and, at harvest, the crop yield and both the organoleptic and nutritional (organic acids, carbohydrates, flavonoid and non-flavonoid phenolic compounds) grape quality. From the preliminary findings, we can conclude that physiological responses, such as water relations, of table grape vines could be influenced by the rootstock type, whilst metabolomic characterization of mature grapes suggest that the fruit quality was mainly dependent on the cultivar genotype, even though the different size-controlling rootstocks exerted a relevant influence, especially on vines under restricted water regime.

Gene expression analysis of metallothionein and mineral elements uptake in tomato (Solanum lycopersicum) exposed to cadmium

Heavy metals such as Cd are considered to be the most important pollutants in soil contamination. Cd is a non-essential element adversely affecting plant growth and development, and it has caused some physiological and molecular changes. Metallothioneins (MTs) are low molecular weight, cysteine-rich, and metal binding proteins. In this study, we aimed to evaluate the MT gene expression levels and minerals uptake in the tissues of Solanum lycopersicum exposed to Cd. The transcriptional expression of the MT genes was determined by real-time quantitative PCR. The MT genes were regulated by the Cd and the mineral elements uptake changed tissue type and applied doses. The MT1 and MT2 transcript levels increased in the roots, the leaves and the fruits of the tomato. The MT3 and MT4 transcript pattern changed according to the tissue types. The Cd treatment on the growth medium increased the Mg, Ca, and Fe content in both the leaves and fruits of the tomato. However, the Cd affected the mineral levels in the roots depending on the mineral types and doses. Also, the Cd content increased in the roots, the leaves, and the fruits of the tomato, respectively. The results presented in this study show that Cd has synergistic and/or antagonistic effects on minerals depending on the tissue types. These results indicate that the MT1 and MT2 expression pattern increased together with the Mg, Ca, and Fe content in both the leaves and the fruits of the tomato.

Visualization of Uptake of Mineral Elements and the Dynamics of Photosynthates in Arabidopsis by a Newly Developed Real-Time Radioisotope Imaging System (RRIS).

Minerals and photosynthates are essential for many plant processes, but their imaging in live plants is difficult. We have developed a method for their live imaging in Arabidopsis using a real-time radioisotope imaging system. When each radioisotope, 22Na, 28Mg, 32P-phosphate, 35S-sulfate, 42K, 45Ca, 54Mn and 137Cs, was employed as an ion tracer, ion movement from root to shoot over 24 h was clearly observed. The movements of 22Na, 42K, 32P, 35S and 137Cs were fast so that they spread to the tip of stems. In contrast, high accumulation of 28Mg, 45Ca and 54Mn was found in the basal part of the main stem. Based on this time-course analysis, the velocity of ion movement in the main stem was calculated, and found to be fastest for S and K among the ions we tested in this study. Furthermore, application of a heat-girdling treatment allowed determination of individual ion movement via xylem flow alone, excluding phloem flow, within the main stem of 43-day-old Arabidopsis inflorescences. We also successfully developed a new system for visualizing photosynthates using labeled carbon dioxide, 14CO2. Using this system, the switching of source/sink organs and phloem flow direction could be monitored in parts of whole shoots and over time. In roots, 14C photosynthates accumulated intensively in the growing root tip area, 200–800 µm behind the meristem. These results show that this real-time radioisotope imaging system allows visualization of many nuclides over a long time-course and thus constitutes a powerful tool for the analysis of various physiological phenomena.

Transporters involved in mineral nutrient uptake in rice.

One of the most important roles of plant roots is to take up essential mineral nutrients from the soil for use in plant growth and development. The uptake of mineral elements is mediated by various transporters belonging to different transporter families. Here we reviewed transporters for the uptake of macronutrients and micronutrients identified in rice, an important staple food for half of the world's population. Rice roots are characterized by having two Casparian strips on the exodermis and endodermis and by the formation of aerenchyma in the mature root zone. This distinct anatomical structure dictates that a pair of influx and efflux transporters at both the exodermis and endodermis is required for the radial transport of a mineral element from the soil solution to the stele. Some transporters showing polar localization at the distal and proximal sides of the exodermis and endodermis have been identified for silicon and manganese, forming an efficient uptake system. However, transporters for the uptake of most mineral elements remain to be identified.

Induction of salt stress tolerance in cowpea [<italic>Vigna unguiculata</italic> (L.) Walp.] by arbuscular mycorrhizal fungi

The aim of present study was to examine the effect of arbuscular mycorrhizal fungi (AMF) on the growth, lipid peroxidation, antioxidant enzyme activity and some key physio-biochemical attributes in cowpea (<italic>Vigna unguiculata</italic> [L.] Walp.) subjected to salt stress. Salt stress (200 mM NaCl) reduced growth, biomass, relative water content and chlorophyll pigment content in cowpea leaves. AMF ameliorated the negative impact of salinity on the growth parameters studied. The activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and glutathione reductase (GR) enhanced under salt stress and AMF inoculation further enhanced their activity, thus strengthening the plant’s defense system. Proline content increased in salt stressed plants as well as AMF-inoculated plants providing efficient protection against salt stress. Besides this AMF also increased uptake of mineral elements which have direct impact on the osmoregulation of the plants. The present study shows that AMF possesses the potential to enhance salt tolerance of cowpea.

Effects of Eucalyptus saligna biochar-amended media on the growth of Acmena smithii, Viola var. hybrida, and Viola × wittrockiana

SummaryBiochar has been proposed as a suitable component for growing media; however, little research has been done on the effects of biochar-amended media on ornamental plant growth. We investigated the effects of four rates of application of Eucalyptus saligna wood biochar [0, 2.5, 5.0, or 10.0% (w/w)] in combination with three rates of a controlled-release fertiliser [CRF; 0 (no CRF), 3 kg m-3 (half-rate CRF), or 6 kg m-3 (the recommended rate of CRF)] on the growth of lilly pilly (Acmena smithii), pansy (Viola var. hybrida), and viola (Viola ?? wittrockiana) in a glasshouse experiment. The results showed that dry weight yields increased significantly in all species studied in response to an increase in CRF treatment; however, there was no significant effect of biochar treatment on any species. The combined application of biochar and CRF had significant effects on the concentrations and uptake of different mineral elements by all three species; however, the results were highly variable and no consistent trend was observed. We suggest that the positive responses in nutrient uptake could be attributed to improved fertiliser-use efficiency, as indicated by a higher dry weight yield per unit weight of CRF applied. It is unclear from our results whether E. saligna wood biocharamended growing media could provide nutrients directly to the species studied. Further studies are required to determine whether growing media amended with this biochar are suitable for use in ornamental nursery production.

Influence of rootstocks on growth, yield, fruit quality and leaf mineral element contents of pear cv. 'Santa Maria' in semi-arid conditions.

BackgroundRootstocks play an essential role to determining orchard performance of fruit trees. Pyrus communis and Cydonia oblonga are widely used rootstocks for European pear cultivars. The lack of rootstocks adapted to different soil conditions and different grafted cultivars is widely acknowledged in pear culture. Cydonia rootstocks (clonal) and Pyrus rootstocks (seedling or clonal) have their advantages and disadvantages. In each case, site-specific environmental characteristics, specific cultivar response and production objectives must be considered before choosing the best rootstock. In this study, the influence of three Quince (BA 29, Quince A = MA, Quince C = MC) and a local European pear seedling rootstocks on the scion yield, some fruit quality characteristics and leaf macro (N, P, K, Ca and Mg) and micro element (Fe, Zn, Cu, Mn and B) content of ‘Santa Maria’ pear (Pyrus communis L.) were investigated.ResultsTrees on seedling rootstock had the highest annual yield, highest cumulative yield (kg tree−1), largest trunk cross-sectional area (TCSA), lowest yield efficiency and lowest cumulative yield (ton ha−1) in the 10th year after planting. The rootstocks had no significant effect on average fruit weight and fruit volume. Significantly higher fruit firmness was obtained on BA 29 and Quince A. The effect of rootstocks on the mineral element accumulation (N, K, Ca, Mg, Fe, Zn, Cu, Mn and B) was significant. Leaf analysis showed that rootstocks used had different mineral uptake efficiencies throughout the early season.ConclusionThe results showed that the rootstocks strongly affected fruit yield, fruit quality and leaf mineral element uptake of ‘Santa Maria’ pear cultivar. Pear seedling and BA 29 rootstock found to be more prominent in terms of several characteristics for ‘Santa Maria’ pear cultivar that is grown in highly calcareous soil in semi-arid climate conditions. We determined the highest N, P (although insignificant), K, Ca, Mg, Fe and Cu mineral element concentrations on the pear seedling and BA 29 rootstocks. According to the results, we recommend the seedling rootstock for normal density plantings (400 trees ha−1) and BA 29 rootstock for high-density plantings (800 trees ha−1) for ‘Santa Maria’ pear cultivar in semi-arid conditions.