In vitro propagation using adventitious buds technique as a source of new variability in chrysanthemum

Eleven cultivars of Chrysanthemum × grandiflorum (Ramat.) Kitam.: ‘Richmond’ and its 10 radiomutants, representing the Lady group, were propagated in vitro with shoot tips and leaves as explants. The aim of this study was to investigate if the explant type used for micropropagation affects the genotype and phenotype of chrysanthemums. Plants grown from shoot tips and adventitious buds formed on leaves were rooted in vitro, acclimatized and cultivated in glasshouse up to full-flowering. The colour and shape of inflorescences of plants obtained from two different explant types were compared within the cultivars. All plants derived from shoot-tip explants showed the inflorescence colour and shape typical for the cultivars. Inflorescence colour of plants derived from adventitious buds were true-to-type in four cultivars: ‘Richmond’, ‘Lady Amber’, ‘Lady White’ and ‘Lady Yellow’. All plants of ‘Lady Apricot’ (originally: golden beet) and ‘Lady Salmon’ (salmon) propagated from adventitious buds technique showed altered inflorescence colour (respectively: purple gold; pink and white). ‘Lady Bronze’ (originally: reddish brown), ‘Lady Orange’ (orange brown) and ‘Lady Rosy’ (purple gold) propagated with adventitious buds had both typical and changed inflorescence colours (respectively: yellow; yellow and red; reddish pink). ‘Lady Vitroflora’ showed altered number of ligulate florets grown into tubes in inflorescence when propagated with shoot tips and leaves as explants. Those changes might be an effect of either chimeral structure or somaclonal variation of the plants investigated. The variation appears only if non-meristematical explants were used. The adventitious buds technique might be useful in chrysanthemum breeding as a source of a new variability.     

托桂型菊花花器性状杂种优势与混合遗传分析

以托桂型菊花品种‘QX-053’为母本,非托桂型菊花品种‘南农惊艳’为父本配制组合,调查F1代10个花器性状在2012和2013年的表型,运用单个分离世代的主基因 + 多基因混合遗传模型进行花器性状遗传分析。结果表明：10个花器性状均存在一定的杂种优势,除花径、舌状花数、舌状花长和管状花宽外,心花直径、舌状花宽、管状花数、管状花长、最深齿裂长和花柱长等6个性状的中亲优势值均达极显著水平。10个花器性状中,花径、心花直径、舌状花长、舌状花宽、管状花数、管状花长和花柱长均符合A-0模型,即无主基因控制,可能受环境影响比较大的多基因控制;而舌状花数、管状花宽、最深齿裂长符合B-1模型,即表现为加性-显性-上位性的两对主基因控制,主基因遗传率分别为93.85%、42.86%和52.00%。     

菊花花青素苷合成关键基因表达与花色表型的关系

 以切花菊（Chrysanthemum × morifolium Ramat.）粉色花品种‘日切桃红’（‘DF-3’）和其白色花突变体（‘MD’）的舌状小花为材料,研究花青素苷生物合成途径6个结构基因和3个调节基因表达对花色表型的影响。HPLC分析结果发现,‘DF-3’舌状花中含有2种矢车菊素苷衍生物cyanidin 3-O- （6"-O-monomalonyl-beta-glucopyranoside）和cyanidin 3-O-（3",6"-O-dimalonyl-beta-glucopyranoside）,而‘MD’舌状花中不含花青素苷。半定量RT-PCR分析结果显示,在‘DF-3’中结构基因CHI、F3H、F3′H的表达模式相似,在LⅠ期（花蕾直径 < 0.5 cm）均已有表达,表达量随着花序发育上升,在HⅡ期（外层舌状花直立,未展开）达到高峰,随后逐渐下降;结构基因CHS、DFR和ANS在蕾期表达弱,在HⅡ期表达量达到高峰,随后逐渐下降;且DFR和ANS只在舌状花中表达。调节基因WD40和bHLH均先于结构基因在LⅢ时期（外层1 ~ 2轮舌状花展开）即有强烈表达;MYB在蕾期无表达,在HⅠ期才开始表达,在HⅢ期达到表达高峰。突变体中结构基因和调节基因在各发育阶段的表达量均比野生型下调,其中F3H和ANS表达极弱,DFR始终没有检测到表达信号,调节基因MYB和WD40的表达量下调,bHLH的表达量非常微弱。这些结果表明,菊花舌状花中矢车菊素苷的积累是CHS、CHI、F3H、F3′H、DFR和ANS等关键结构基因共同表达的结果,突变体中调节基因MYB和bHLH的表达下调可能与其白花形成有密切关系。     

The effect of forcing temperature on peony shoot and flower development

Pre-chilled potted plants of Paeonia ‘Coral Sunset’, ‘Monsieur Jules Elie’, ‘Sarah Bernhardt’, and ‘Karl Rosenfeld’ were placed in a range of controlled temperature regimes to ascertain the effect of temperature on the timing of shoot emergence and floral development. For all cultivars, warmer temperatures up to 25 °C lead to more rapid shoot emergence and flower development. Linear temperature responses adequately described the rate of development from shoot emergence to flower bud appearance, and from bud appearance to flower opening, but a curvilinear response was required to describe the time taken for shoots to emerge. There were significant differences between cultivars in the number of heat units required for shoot emergence, with the shoots of the slowest-developing cultivar, ‘Monsieur Jules Elie’, taking 50% longer to emerge than those of the most rapid, ‘Coral Sunset’. No significant differences were found among cultivars in the time taken from shoot emergence to flower opening, although the ‘split’ stage (when the bud opens sufficiently for petal colour to be observed) was slightly earlier in ‘Karl Rosenfeld’.     

小菊新品种‘东篱红云’和‘东篱月光’

小菊新品种‘东篱红云’和‘东篱月光’均以自育株系‘388’为母本,以从德国Brandkamp公司引进的多个品种为父本进行人工杂交,经连续选择育成。‘东篱红云’舌状花粉色,观赏期9月下旬到10月下旬。‘东篱月光’舌状花展开前嫩黄色,展开后变为白色,观赏期9月中旬到10月下旬。开花期均早,株形圆整,分枝性强,适于盆栽或地栽,可以满足北京地区国庆节用花需求。     

Seasonal effects of seed age on regeneration potential and transformation success rate in three citrus cultivars

The effects of seed age on shoot regeneration potential and transformation rate of ‘Duncan’ and ‘Flame’ grapefruit cultivars, along with ‘Hamlin’ sweet orange cultivar were investigated. Shoot regeneration potential of all three cultivars varied throughout the season. Cumulative data for shoot regeneration of explants incubated in bacterial suspension exhibited higher values early in the season and in the first months of the spring, with significant drops during the winter months and later in the season. Transformation rate did not vary as much as shoot regeneration potential. Data describing the propensity of ‘Flame’ and ‘Hamlin’ tissue for genetic transformation exhibited a negative trend as the season progressed. ‘Duncan’ transformation rate held steady during the season. Taken together, our results confirm the need for specific culturing protocols to be developed and used for different citrus cultivars at specific times to reduce variability of responses these cultivars exhibit to culturing conditions and transformation attempts.     

切花小菊41 个品种花粉量的测定与散粉特性分析

 研究了41 个切花小菊品种的散粉特性及影响散粉量的关键指标,旨在为培育散粉少或不散 粉切花小菊奠定基础。结果发现：（1）供试的切花小菊品种每花序管状花数的变化范围为85.6 ~ 320.2 个, 绝大多数品种单花花药数为5 枚,花药含粉量变幅为0 ~ 1 017 粒,花序含粉量变幅为0 ~ 807 840 粒;（2） 9 个品种未散粉（其中8 个品种的花药内有花粉,但花药不开裂,仅‘Kingfisher’一个品种花药内没有 花粉）,11 个品种散粉量较少,9 个品种散粉量中等,12 个品种散粉量较多。应用聚类分析分别对各品种 花药含粉量和花序含粉量进行了评价,将花粉量聚类为多、中等、少、无4 类,其中,中等和少的品种 占80%。试验结果表明,切花小菊散粉量不仅与花序中管状花数和花药含粉量成正比,而且与花药开裂 速度和开裂程度成正比。     

Prolonged high-temperature exposure differentially reduces growth and flowering of 12 Viola × wittrockiana Gams. cvs

Many cool season garden crops, including Viola × wittrockiana Gams. (pansy), exhibit reduced flowering outdoors during the warm summer months. Twelve pansy cultivars varying in summer garden performance were grown under either 20 ± 1.5 or 30 ± 1 °C (air temperature) to determine growth and flowering responses to prolonged high-temperature exposure and to identify selection criteria to screen pansies for flowering heat tolerance. Increasing temperature from 20 to 30 °C increased leaf number below the first flower on ‘Crystal Bowl Primrose’ and ‘Skyline White’ only. Flower bud number reduction at 30 °C versus 20 °C varied from 20% for ‘Crystal Bowl Purple’ to 77% for ‘Majestic Giants Red and Yellow’. Flower diameter reduction at 30 °C versus 20 °C ranged from 14% for ‘Skyline Beaconsfield’ to 44% for ‘Super Majestic Giants Ocean’. The percentage reduction in total color (flower number × estimated flower area) ranged from 60% for ‘Crystal Bowl Primrose’ to 88% for ‘Majestic Giants Rose Shades’. Based on a weighted base selection index, ‘Super Majestic Giants Canary’ and ‘Delta Yellow’ were identified as the most heat-tolerant cultivars, while ‘Super Majestic Giants Ocean’ and ‘Majestic Giants Rose Shades’ were identified as the most heat-sensitive. In a second experiment, root and shoot dry mass were determined after 10, 20, or 30 d when grown at 20 or 30 °C. Relative growth rate and root:shoot ratio were also calculated. After 30 d, ‘Crystal Bowl Primrose’, ‘Crystal Bowl Sky Blue’ and ‘Skyline White’ relative growth rates were lower at 30 °C versus 20 °C. Root:shoot ratio on day 30 was lower at 30 °C compared to 20 °C for six cultivars, but similar across temperature for five cultivars and higher for ‘Crystal Bowl Primrose’. Flower bud number at first flower was positively correlated with branch number, shoot dry mass at flowering, but not correlated with root dry mass at flowering, and negatively correlated with flower diameter and root:shoot ratio (either at flowering, or after 10, 20 or 30 d at 30 °C), suggesting that these traits may be useful when screening pansies for flowering heat tolerance.     

60Co-γ辐射对切花菊试管苗的诱变效应

以‘神马’和‘长紫’两个切花菊品种的生根试管苗为试材,用60Co-γ射线进行辐射,设0（对照）、10、15和20 Gy等4个剂量处理,处理后以茎段和叶片为外植体进行离体培养,分析辐射对腋芽发生率、愈伤组织诱导率和分化率的影响,统计M1代田间主要性状及变异情况。结果表明：γ射线对试管苗茎段和叶片的愈伤组织诱导及分化有明显抑制作用,随着辐射剂量的增加抑制作用加强。不同品种、不同外植体对辐射的敏感程度都存在差异。茎段较叶片更适合做辐射后组培的外植体。‘长紫’M1代株高降低,花径减小;而‘神马’在株高和花径出现略微增加的趋势。茎段和叶片的再生植株田间主要性状的变异程度大于腋芽的再生植株。‘长紫’在花色和瓣形上的变异率高于‘神马’。     

番茄品种与砧木苗期耐盐性指标评价及耐盐品种筛选

为了筛选出耐盐的番茄品种和砧木品种,确定番茄幼苗的可适应盐浓度、筛选强度和可用于鉴别番茄苗期耐盐性的指标,试验以19 个番茄栽培品种和3 个砧木品种为试材,在苗期浇灌不同盐浓度的营养液,对幼苗生长等相关指标进行测定并进行相关分析。结果表明佳西娜（产地荷兰,樱桃番茄,红果）和瑰丽绝粉（产地甘肃,大果,粉果）为耐盐的番茄品种,番茄砧木406（产地山东,大果,红果）为耐盐的番茄砧木品种。在每隔2 d 1 次的灌溉强度下,番茄苗期可适应盐浓度为4 g·L^-1,筛选强度为8 g·L^-1。可以作为鉴别番茄幼苗耐盐性的指标为全株干质量、地上部干质量、根干质量、株高、茎粗、功能叶片数和壮苗指数,而根冠比则不可作为番茄幼苗耐盐性的鉴别指标。     

Adventitious shoot regeneration from hypocotyl slices of mature apricot (Prunus armeniaca L.) seeds: A feasible alternative for apricot genetic engineering

Adventitious shoot regeneration from hypocotyl slices of mature apricot seeds has been achieved with regeneration percentages of 31.7%, 44.4%, and 46.9% for the cultivars ‘Canino’, ‘Dorada’, and ‘Moniqui’, respectively. Regeneration was significantly affected by the parental origin of the explants (P < 0.05) but not by thidiazuron or 3-indolebutyric acid for any of the three cultivars, at the levels tested. None of the other factors studied (basal medium, 2,4 dichlorophenoxy-acetic acid pulses, dark incubation period, or addition of silver thiosulfate) affected significantly shoot regeneration percentage from ‘Canino’ hypocotyl sections. The effect of paromomycin on regeneration was genotype-dependent and different dose–response curves were obtained for each cultivar. While 40 μM paromomycin completely inhibited regeneration from ‘Canino’ sections, some buds were obtained from ‘Dorada’ and ‘Moniqui’ explants. The two aminoglycoside antibiotics tested, kanamycin and paromomycin, showed differing toxicity on ‘Canino’. A lower concentration of kanamycin (20 μM) than of paromomycin inhibited totally adventitious regeneration from ‘Canino’ explants. Agrobacterium-mediated transformation experiments, with the non-oncogenic strain AGL1 harboring the binary plasmid p35SGUSINT, were performed and GUS assays were carried out after four weeks to determinate stable transformation events. The utilization of paromomycin (10 μM) as the selective agent increased significantly both the number of explants that presented at least one transformation event (P < 0.05) and the number of large area or calli expressing the gus gene (P < 0.001), compared with the addition of kanamycin (10 μM). Moreover, when 10 μM paromomycin was added to the medium some massively transformed explants were observed and a chimerical bud was regenerated.     

Improvement of flower color by means of leaf treatments in lily

Flower color, an important feature biologically and commercially, is based on four natural pigments – flavonoids, carotenoids, betalains and chlorophylls. Temperature, light, nutrition – as well as additions of sugar, salt, or metals to the conservation water – have an effect on pigmentation. We investigated the effects of K-sulphate and/or sucrose on flower color in leaf treatments applied 30–10 days before harvest to four Asiatic lily (Lilium × elegans Thunb.) cultivars during the winter and summer. Colors of tepals were evaluated by a portable spectrocolorimeter that calculates the standard CIE L*a*b* coordinates and the color differences (E). After leaf treatments during both seasons, cultivars with flowers with high red components (e.g. the purple ‘Fangio’ and the pink ‘Brindisi’) showed significant improvements in color quality. The orange-flowered ‘Tresor’ showed improvement only if K-sulphate and Mix (K-sulphate and sucrose) solution treatments were applied during the summer. The yellow-flowered ‘Menorca’ was not affected by treatments during either summer or winter forcing season. Especially in the winter, a significant reduction in flower abortion was observed for cut flowers of all cultivars. In summer only ‘Fangio’ and ‘Tresor’ showed a reduction in flower abortion. Also, flower size and longevity were improved by the leaf treatment. The results, obtained from a commercial nursery operation, demonstrate that lily growers can adopt a very simple and inexpensive treatment to improve important qualitative traits of their product.     

Comparative forcing of Hydrangea macrophylla ‘Bailer’ as a florist's hydrangea

‘Bailer’ (Endless Summer™) is a new, pink- or blue-flowered hydrangea that flowers on new wood continuously throughout the growing season. It is also winter-hardy in northern, temperate climates (USDA Z4). Use of Endless Summer as a florist's potted hydrangea would provide consumers with a dual-use product (flowering potted plant, landscape shrub). The objectives were to determine if Endless Summer could be forced as a florist's hydrangea using two forcing regimes (immediate, standard), two soil pH regimes, and two pinching treatments. ‘Merritt Supreme Pink’ (pink), ‘Blue Danube’ (blue), and Endless Summer (blue, pink) were forced under immediate (no cold treatment, short- and long-day photoperiods) and standard (6 weeks cold, 4 °C to overcome dormancy) conditions. Since commercial liners were not yet available, cuttings of Endless Summer were used in the immediate forcing experiment. Days to visible flower bud, first color, full flower were recorded, as well as height, no. of branches, no. of flowers, and flower size. In the immediate forcing experiment, only Endless Summer produced flowers. Cultivars differed significantly (P < 0.001) for days to visible flower bud, days to first color, days to full flower, and height. The number of flowers and flower size were not significantly different among pink cultivars. In the standard forcing experiment, Endless Summer reached days to visible flower bud, days to first color, and days to full flower significantly earlier than either comparison, although it exhibited weaker stems and less intense flower pigmentation. Pinching (blue pH) had a significant effect on all traits except the days to full flower and flower size, although no pinching treatment was significant for pink pH. Photoperiod was significant only for the days to visible flower bud (pink pH), days to full flower (blue pH), and final height (blue pH). Further research is needed before Endless Summer can be grown as a dual-use florist's potted hydrangea with acceptable quality.     

Increase in the number of decorative florets in the inflorescence of Hydrangea through phytoplasma infection

Hydrangea (Hydrangea spp.) has two types of florets in an inflorescence. One has decoratively developed sepals and is termed as the decorative floret. The other has plain sepals and is termed as the non-decorative floret. Hydrangea is classified into two types according to its inflorescence: globular (hortensia) and lacecap. In hortensia, the surface of inflorescence is covered with decorative florets. In lacecap, decorative florets are situated around the periphery of the inflorescence. Japanese hydrangea phyllody (JHP) phytoplasma infection often leads to an increase in the number of decorative florets. JHP phytoplasma was inoculated into ten hortensia and five lacecap cultivars by grafting. The ratios of decorative florets to total florets were compared between the JHP phytoplasma-infected and non-infected plants. The infected plants showed lower decorative floret ratios in six hortensia cultivars and higher decorative floret rations in four lacecap cultivars. The composition of inflorescence was investigated using infected and non-infected plants of ‘Midoribanaajisai’ (hortensia cultivar) and ‘Libelle’ (lacecap cultivar). In ‘Libelle’, the lacecap type, an alteration in the lateral non-decorative floret to the decorative floret was observed and considered to be the main cause of increase in the decorative floret ratio.     

蜂窝型切花菊观赏性状综合评价与筛选

对54个大花蜂窝型切花菊株系,以株高、节间长、茎粗、茎充实度、叶长、叶宽、叶柄角度、花径、花高/花径、舌状花数和管状花数共11个观赏性状作为评价因子,利用层次分析法建立综合评价体系,并开展株系的筛选。研究确定了各性状的权重值,其中花高/花径影响最大,权重为0.241,其次是舌状花数和管状花数,权重为0.155和0.111。通过K-Means聚类分析将54个株系分为3个等级,优13个,占24.07%;良30个,占55.56%;差11个,占20.37%。通过层次分析法及K-Means聚类分析可以有效地对蜂窝型切花菊株系观赏性状进行综合评价,并选出符合育种目标的优良后代,为新品种选育提供重要材料。     

菊花新品种‘东篱雅致’

菊花新品种‘东篱雅致’是以中国传统大菊品种‘绿朝云’为母本,以花形奇特、不同色系的‘钟声’,‘清水莲’和‘笑靥’等传统大菊品种作父本进行人工混合授粉,经连续选择育成。舌状花松针形,粉、绿复色。植株低矮, 直立性强, 适于盆栽观赏, 主要观赏期11月中旬—下旬,可以用于北京地区节日布展或庭院观赏。     

Flower greening in phytoplasma-infected Hydrangea macrophylla grown under different shading conditions

To determine the effect of light intensity on flower greening, the Japanese hydrangea phyllody (JHP) phytoplasma-infected hydrangea cultivars ‘Midori’, ‘Libelle’, ‘Rosea’ and ‘Madame E. Mouillere’ plants were grown under different shade conditions. In the first-year experiment, the results indicate that the flowers of the JHP-phytoplasma-infected hydrangea become green under shaded conditions (70% and 49% sunlight intensities). On the other hand, under full sunlight intensity (100% sunlight intensity), the flowers of ‘Midori’, ‘Rosea’, and ‘Libelle’ plants were blue, pink or white. To calculate the percentage of flower greening, inflorescences of these plants were separated and divided into individual flowers, and classified into four types by green-area ratio, calculated using Adobe Photoshop. Under shading with one sheet of cheesecloth (70% sunlight intensity), the inflorescences of ‘Midori’, ‘Libelle’ and ‘Madame E. Mouillere’ plants were composed of more than 40% completely green flowers (0.8 ≦ green-area ratio), whereas those of ‘Rosea’ plant had 0% completely green flowers. Under shading with two sheets of cheesecloth (49% sunlight intensity), the inflorescences of ‘Midori’, ‘Libelle’ and ‘Madame E. Mouillere’ plants had more than 75% completely green flowers; ‘Rosea’ plants had 28%. In the second-year experiment, under full sunlight intensity, ‘Midori’ plants had four types of flower depending on their green-area ratio, namely, completely blue or pink, pink-green, greenish and completely green flowers. Under shading with two sheets of cheesecloth, ‘Midori’ plants had more than 90% completely green flowers. The JHP-phytoplasma could not be identified by PCR analysis in flowers with a green-area ratio = 0 (completely blue/pink/white flowers). On the other hand, in flowers with a green-area ratio > 0, the JHP-phytoplasma was detected by PCR analysis. Thus, we conclude that shading enhances flower greening in hydrangea by increasing the JHP-phytoplasma concentration in the flowers.     

Partitioning of C-photosynthates from different current shoots neighboring with fruiting spur in later-maturing Japanese pear during the period of rapid fruit growth

To elucidate the fate of photosynthates from different current shoots and their influence on fruit growth and bud differentiation in neighboring spur complex during the period of rapid fruit growth in two late-maturing Japanese pear cultivars: ‘Atago’ and ‘Shinkou’ with contrasting fruit size, ¹³C labeling of single shoot was done to investigate of C-relations in fruit branches of eight shoot-combinations. The results showed that all of the current shoots investigated (bourse shoots of nonfruiting spur, bourse shoots of fruiting spur, extension shoot, nonfruiting spur, vegetative shoot, and water sprout) could export photosynthates to the neighboring fruit and buds. Water sprouts together with vegetative shoots, bourse shoots, and extension shoots are important source for fruit growth after shoot growth termination during the period of rapid fruit growth in production of late-maturing pears. The carbon transfer rate from the neighboring to the fruit bearing spur is depent (i) on the types of shoot which acts as C source, (ii) on the position of the fruiting spur and (iii) on the source-sink distance. Furthermore, the cultivar difference in carbon partitioning from different current shoot-combinations confirmed that the movement of photosynthates into the fruit was determined by sink strength of the fruit, and ‘Atago’ exhibited a greater relative sink strength of fruit than ‘Shinkou’. In addition, vegetative shoots are very important C sources for fruit growth in ‘Atago’ and the growth pattern of bourse shoot seriously affects C allocated to fruit in ‘Shinkou’.     

小菊新品种‘枫林黄星’和‘枫林红晕’

小菊新品种‘枫林黄星’是以‘Branice Sunny’为母本,‘183’株系为父本经人工杂交选育而成,舌状花亮黄色,头状花序直径3.7 cm,冠幅63.8 cm,单株着花1 007朵。‘枫林红晕’是以‘388’株系为母本,从德国引进的多个品种为父本混合授粉选育而成,舌状花中上部粉色,下部白色,头状花序直径3.6 cm,冠幅60.2 cm,单株着花847朵。两个新品种冠幅大,株形紧凑丰满,呈半圆形,群体效果良好,适于北京地区秋季绿化。     

Assessment of tolerance to NaCl salinity of five olive cultivars,based on growth characteristics and Na and Cl exclusion mechanisms

Changes caused by NaCl-induced salinity on several growth parameters and ions accumulation have been measured in five olive (Olea europaea L.) cultivars (‘Chemlali’, ‘Chetoui’, ‘Koroneiki’, ‘Arbequina I18’, and ‘Arbosana I43’) growing in a greenhouse in nutrient solution pot experiment. One-year-old plants were transplanted to sand–perlite (1:1) culture, and were irrigated with half-strength Hoagland nutrient solution containing NaCl at various levels (0.5, 50, 100 and 200 mM). Salinity induced significant decrease in growth parameters, but to a different extent in each cultivar. Leaf growth and total leaf area per plant were significantly affected by all salinity treatments in all studied cultivars, being ‘Arbequina I18’ the most sensitive cultivar. Leaf drop phenomenon was observed from 60 days after salt application at high salinity treatments, mainly in Arbequina I18. Contrary to leaf area, leaf thickness increased progressively during the experiment. ‘Chemlali’ developed thicker leaves at the two highest salinity treatments when compared to the other cultivars. Na⁺ and Cl⁻ concentrations were higher in roots than in shoots and leaves in most of the cultivars investigated. The effectiveness of Na⁺ exclusion mechanism in the roots differed significantly among studied cultivars, working effectively in ‘Chemlali’ (by inhibiting translocation of Na⁺ to the aerial part) and being much less efficient in ‘Arbequina I18’. Furthermore, leaf abscission can be considered as an additional tolerance mechanism of olive cultivars allowing the elimination of leaves that had accumulated Na⁺ and Cl⁻ ions. Tolerance to salinity stress was as follows: ‘Chemlali’ > ‘Chetoui’ > ‘Arbosana I43’ > ‘Koroneiki’ > ‘Arbequina I18’. This order of salt tolerance was indicated by lower reduction in plant growth parameters (shoot elongation, trunk diameter, total plant dry weight, internodes length, and total leaf area), the increase of leaf thickness, and by the effectiveness of the exclusion mechanism of Na⁺ and Cl⁻ in the root system.