The genetic pool of valuable old ornamental cultivars and their in situ maintenance is threated by climate change. Meanwhile, ornamental plants like roses make up an important share of both gardens ...and urban green spaces, where they are particularly vulnerable to multi-stress growth conditions. The aim of this research was to evaluate the effect of changing climatic conditions on growth and flowering of 11 historic climber roses through long-term studies (2000–2017) conducted in Central Europe. The evaluation of plants consisted of assessment of frost damage and the timing of early phenological stages (starting of bud break, leaf unfolding), as well as gathering data on the beginning, fullness, and end of flowering and its abundance. Frost damage was not observed in any year only in ‘Mme Plantier’ and did not occur for any cultivar after the winter in the years 2007, 2008, and 2014. Only a little damage to one-year shoots was recorded after the winter in the years 2015–2017. Frost damage to ‘Alberic Barbier’, ‘Albertine’, ‘Chaplin’s Pink Climber’, ‘Orange Triumph clg’, and ‘Venusta Pendula’ led to pruning to ground level in every year excluding those listed above. Frost damage of once-blooming roses limited their flowering; however, the many-year datasets showed a trend for decreased frost damage and improved abundance of flowering, and these results can be interpreted as a response to the increase of average air temperature. The timing of bud breaking and leaf development in all climber roses was strictly correlated with average air temperature in the dormancy period. The reactions of climber roses to weather conditions confirmed the influence of climatic changes on ornamental crop plants in Central Europe, introducing the potential possibility for the wider application of climber roses, but without certainty of flowering every year.
Biostimulants and rooting enhancers, i.e., auxins, affect many aspects of plant development. The experiment in this paper focused on the response of single-node rose semi-woody cuttings to ...rhizogenesis-enhancing preparations based on plant extracts in terms of changes in polyphenolic acid content. The shoots were cut at four stages of flowering development: (i) flower buds closed, (ii) open flower, (iii) immediately after petal shedding, (iv) 7–14 days after petal shedding. The experimental material consisted of six old, once-flowering rose cultivars (‘Duchesse d’Angoulême’, ‘Hurdals’, ‘Maiden’s Blush’, ‘Mousseuse Rouge’, Rosa beggeriana ‘Polstjårnan’, R. helenae ‘Semiplena’). The following rooting-enhancers were applied: commercial powder containing (i) 0.4% indolebutyric acid (IBA) or (ii) 0.2% naphthalene acetic acid (NAA) or commercial plant-extract mixtures named in the experiment, i.e., (iii) Seaweed Preparation, (iv) Humic Preparation, and (v) Plant Preparation, and (vi) the control cuttings, which remained untreated. The level of polyphenolic acids was determined before and after rooting. The content of polyphenolic acids had a tendency to decrease during the period of rhizogenesis for all cultivars and all phenological stages. Changes in polyphenolics were affected by all the rooting enhancers, but the contents of these compounds before and after rooting was not found to unambiguously correlate with either the final rooting percentage or quality of cuttings.
Climate change affects the possibility of crop production and yield and disrupting the maintenance of crop biodiversity, including ornamentals. Warsaw is located in a temperate zone with mixed ...continental and oceanic climate influences. This research examines the response of once-blooming rambler roses to changing climate conditions in connection with their frost resistance and ornamental value. The 15 selected rambler rose cultivars were observed in the years 2000-2016 in the Polish Academy of Sciences Botanical Garden-Center for Biological Diversity Conservation in Powsin. Damage to shrubs caused by frost, the timing of bud break, leaf development, and initial, full, and final flowering were recorded. We show that changes in phenology and frost damage were the effect of weather conditions in the autumn-winter-spring period. Frost damage influenced the flowering and growth of plants in different ways, depending on the extent of required pruning. The cultivars most highly tolerant to frost damage were: "Lykkefund", "Polstjårnan", and "Semiplena". During the final years (2014-2016), due to mild winters, all of the studied rose cultivars could be used for a wider range of applications than previously (2000-2006 and 2009-2013). Their reintroduction helped to maintain biodiversity of old cultivars, which makes these roses a proposal for the lowlands of Central Europe.
Most old roses are difficult to root when propagated by cuttings. This research focused on the response of stem cuttings of
Rosa
“Hurdal” to plant origin preparations used as rhizogenesis enhancers ...through changes to the anatomical structure of the basal part of the stem. Cuttings derived from shoots in four phenological stages were prepared for the experiment: flower buds closed (H1); fully flowering (H2); immediately after petals have fallen (H3); 7–14 days after petals have fallen (H4). The cuttings were treated with 0.4% indole butyric acid (IBA; Ukorzeniacz A
aqua
) or 0.2% naphthalene acetic acid (NAA; Ukorzeniacz B
aqua
), and with plant origin preparations: Algae extract (Bio Rhizotonic), Organic preparation (Root Juice
TM
), and Plant extract (Bio Roots). A high rooting percentage in comparison to the control (27.5%) was obtained after treatments of the H1 cuttings with Algae extract (90%), Organic preparation (80%), and Plant extract (75%). The H4 cuttings did not root, probably as a result of an overgrowing callus and limited xylem formation. The anatomical structure of the shoot differed in subsequent phenological stages during the period of rooting in various ways, depending on the rooting enhancer used for treatment. Numerous correlations between rooting percentage and anatomical structure were proved, including the key role of vascular bundles in increasing rooting percentage by widening the vessel diameter.
Heptacodium miconioides is an increasingly popular ornamental plant, originally being endemic to China. The late and long flowering determines its ecological and ornamental value in cultivation. The ...aims of this research were to define and distinguish phenological phases of the development of Heptacodium miconioides in the temperate zone region and identification of anatomical changes within the stem during autumn in relation to phenological phases and climatic conditions. Phenological observations were carried out in Wrocław during 2012-2013, as well as in Warsaw (Poland, 52.6°N, 20.5°E) during 2018-2021. During the last year of research an analysis of the anatomical structure was carried out for young stems that bore flowers that year, as well as older, 2- to 6-year-old ones. The material was collected H1 - 10.09., H2 - 28.09., H3 - 16.10., H4 - 3.11., H5 - 21.11. The width of annual increments in subsequent years was determined; length, width and vessel density in early and latewood for subsequent rings of annual growth was measured, as well as the width of the phloem in 1-6-year-old stems (2016-2021). In the vegetative stage three main stages of development were distinguished (leaf buds have the green tips; full autumn discoloration of leaves; leaves falling). In the generative phase, which lasted on average from August 22
to January the 7
five main phases of development were distinguished (flowering, unripe fruits, ripe fruits, spreading of seeds). Increased average temperature during winter and spring had an effect on the growth pattern: early phenological stages occurred sooner and foliage development lasted 44 days longer. Flowering occurred at a similar date at both observed locations and climatic conditions. This year's shoots flowering on a radial section with axial symmetry, were slightly flattened and in clusters arranged regularly to match the shape. Heptacodium develops 2-6 years old shoots with radial symmetry. The growth ring boundaries are distinct, the wood semi-rings porous, with marked differences in the structure of the primary and secondary shoot. Lignification of tissues before winter ends during late leaf-fall phase. The research indicated the adaptive potential of Heptacodium in response to climatic conditions of temperate zone.
During rhizogenesis, carbohydrates are an important source of energy for the plant tissues. It has been hypothesised that phenological phase of the shoot plays a major role in plant's response to ...rooting stimulants and affects the cuttings' carbohydrate content. Therefore, the purpose of this study was to evaluate the impact of phenological phase of the shoots and the use of rooting stimulants of plant origin on the relationship between rooting abilities and the carbohydrate content in leaves and stems of cuttings. Single-node stem cuttings of Rosa beggeriana 'Polstjärnan' and Rosa helenae 'Semiplena' were harvested from shoots in four phenological stages: flower buds closed (P1), flowers open (P2), immediately after petal shedding (P3), and 7-14 days after petal fall (P4). The following rooting enhancers were used: 0.4% indole butyric acid (IBA) (Ukorzeniacz Aaqua); 0.2% naphthalene acetic acid (NAA) (Ukorzeniacz Baqua); Bio Rhizotonic; and Root Juice™; Bio Roots. Controls included untreated cuttings. The contents of reducing and total soluble carbohydrates in leaves and shoots were estimated before and after rooting. The rooting percentage and rooting degree were determined. A relatively high or moderate natural rooting ability without any treatment were shown by R. beggeriana 'Polstjärnan' in 63.8%-87.5% and by R. helenae 'Semiplena' in 41.3%-72.5% cuttings. IBA and NAA decreased the mean rooting percentage in 'Polstjärnan', but increased it for P4 cuttings in 'Semiplena'. None of the preparations had any impact on the degree of rooting. The mean level of total soluble and reducing sugars in leaves and stems of cuttings before rooting was lower than that of after root formation. The preparations of plant origin positively affected rhizogenesis and sugar contents in plant tissues, but their effect depended on shoot's phenological phase and cultivar. Plant origin preparations may successfully replace those containing IBA or NAA.
Periods of heat and water deficit often occur together and are especially dangerous for plants grown in pots, where the substrate volume for roots is limited. The purpose of the present research was ...to understand the response of shrubs planted in containers to the addition of a starch-based superabsorbent to their growing medium. The growth parameters, physiological conditions, and oxidative stress of Cornus alba ’Aurea’, Hydrangea paniculata ‘Limelight’, and Physocarpus opulifolius ‘Red Baron’ were assessed by adding a hydrogel (1, 2, or 3 g·dm−3) to their growing medium. The use of the superabsorbent improved the stomatal conductance and photosynthetic rate, resulting in better growth parameters. The application of 1 g·dm−3 hydrogel increased the chlorophyll content in hydrangea and ninebark leaves (8%) and increased the content of total soluble sugars in these plants (12% and 15%, respectively). The highest increase in reducing sugars was caused by a dosage of 3 g·dm−3. The lowest dose of hydrogel resulted in a decrease in hydrogen peroxide content in the leaves of all the taxa. The relationship between the contents of biologically active components and oxidative stress proved ambiguous for all the taxa. Oxidative stress was reduced, as evidenced by lower hydrogen peroxide and an increase in pigment content. In summary, a hydrogel dosage of 2 g·dm−3 in the medium could be optimal in pot nursery production using 3 dm3 pots.
Some biostimulants, including plant origin preparations, act similarly to plant growth regulators. Moreover, the supplementation of known and unknown rooting cofactors can stimulate rhizogenesis in ...cuttings. The aim of this research was to assess the response of difficult-to-root and long-rooting stem cuttings of the once-blooming old variety Rosa ‘Hurdal’ to preparations of plant origin. The hypothesis was that the plant origin preparations could enhance rooting processes by inhibiting chlorophyll a/b degradation in leaves and postponing leaf senescence, simultaneously increasing the quality of cuttings. The one-bud stem cuttings were made in four phenological stages: (H1) flower buds closed, (H2) open flowers, (H3) just after petal fall, and (H4) 7–14 days after petal shedding. They were treated with either standard commercial powder preparations containing 0.4% indole-3-butyric acid (IBA) or 0.2% 1-naphthalene acetic acid (NAA) as well as with commercial plant origin preparations that this work will henceforth refer to as: Algae Extract, Organic Preparation, and Plant Extract. The cuttings were evaluated after 12 weeks of rooting them in two substrates: peat–perlite and peat–sand (v:v; 1:1). Mean root percentages for both substrates were noted after preparation from stage H1 (74.5%), H2 (59.5%), H3 (50.8%) shoots. The H4 cuttings did not root at all and were not considered further. The means for all phenology stages together were the highest by the use of 0.6% Algae Extract, 0.012% and 0.02% Organic Preparation, and 0.2% and 0.4% Plant Extract. The lowest means were reported for the control cuttings as well as NAA and IBA treatment. Plant origin preparations encouraged growth parameters but did not unequivocally inhibit the decrease of chlorophyll content in the cuttings’ leaves. The percentage of cuttings that rooted in both rooting substrates was determined by the quality of the cuttings as well as the chlorophyll a/b and soluble protein content in the leaves.
Once-blooming roses belong to difficult-to-root. One-bud leafy cuttings have limited storage capacity, due to the small size of the stem, and are exposed to prolonged stress conditions. The objective ...of this study was to examine if the treatment of the cuttings of Rosa × alba ‘Maiden’s Blush’ with plant origin preparations as rooting enhancers may increase their rooting percentage, chlorophyll a/b, and proteins concentration in leaves. The cuttings were prepared from shoots in four phenological stages: flower buds closed, flowers open, immediately after petal shedding, and 7–14 days after petal fall. The following were used: 0.4% indole butyric acid (Ukorzeniacz Aaqua), 0.2% naphthalene acetic acid (Ukorzeniacz Baqua), Bio Rhizotonic; Root Juice™, and Bio Roots. Controls included untreated cuttings. The highest rooting percentage was obtained after two treatments with 0.6% Bio Rhizotonic (81.5%), compared to the control (55.0%), using cuttings from shoots with flower buds closed, but the rooting enhancers did not show any unequivocal impact on rooting percentage in cuttings of all phenological stages or affected improvement this feature in cuttings harvested 7–14 after shedding petals with low root ability. However, the action of plant preparations affected positively higher soluble proteins and chlorophyll content. The plant-origin preparations can be used as alternatives to chemicals in nursery production.
Biostimulants and rooting enhancers, i.e., auxins, affect many aspects of plant development. The experiment in this paper focused on the response of single-node rose semi-woody cuttings to ...rhizogenesis-enhancing preparations based on plant extracts in terms of changes in polyphenolic acid content. The shoots were cut at four stages of flowering development: (i) flower buds closed, (ii) open flower, (iii) immediately after petal shedding, (iv) 7-14 days after petal shedding. The experimental material consisted of six old, once-flowering rose cultivars ('Duchesse d'Angoulême', 'Hurdals', 'Maiden's Blush', 'Mousseuse Rouge', Rosa beggeriana 'Polstjårnan', R. helenae 'Semiplena'). The following rooting-enhancers were applied: commercial powder containing (i) 0.4% indolebutyric acid (IBA) or (ii) 0.2% naphthalene acetic acid (NAA) or commercial plant-extract mixtures named in the experiment, i.e., (iii) Seaweed Preparation, (iv) Humic Preparation, and (v) Plant Preparation, and (vi) the control cuttings, which remained untreated. The level of polyphenolic acids was determined before and after rooting. The content of polyphenolic acids had a tendency to decrease during the period of rhizogenesis for all cultivars and all phenological stages. Changes in polyphenolics were affected by all the rooting enhancers, but the contents of these compounds before and after rooting was not found to unambiguously correlate with either the final rooting percentage or quality of cuttings.
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