Propagation of black currants by single-noded cuttings

Single-noded cuttings were taken from four regions of one-year-old black currant shoots in September 1966, before winter chilling had begun, and stored at 1 °C for 0, 4, 8 or 12 weeks before being inserted in seed trays and placed in a growth room at 20 °C, with continuous illumination. Cuttings from the lower half of shoots rooted and grew well with or without chilling, but cuttings from the upper middle quarter of shoots rooted better after 8 or more weeks in cold storage. Few cuttings from the top region rooted, even after 12 weeks of cold. Cold storage accelerated subsequent bud burst, as did 2 minutes’ treatment with GA₃ at 100 ppm.

In the field, dormancy of buds on intact plants increased after September and was pronounced in December. However, cuttings from all regions of shoots taken from plants in the field in January and immediately placed in the growth room rooted and grew well     

Effect of leaf retention and flavonoids on rooting of Ilex paraguariensis cuttings

The effect of the mature leaf retention and the exogenous application of flavonoids (naringenin, quercetin and rutin at 30 μM for 12 h) was studied for adventitious rooting of Ilex paraguariensis cuttings. Softwood cuttings harvested from young 3-year-old plants and adult 10- and 20-year-old plants were rooted under intermittent fog. A strong correlation (r² = 0.72) between leaf retention and rooting was noted. The highest percentage of adventitious root formation (40%) was obtained when the leaf was artificially removed after 42 days of incubation. This data was supported by the histological analysis which provided anatomical evidence that cuttings have initiated root primordia by 21 days and the regenerated roots emerge through the epidermis after 35 days of incubation. A strong correlation between the position of the leaf and the site of roots regeneration was observed. A 100% of the rooted cutting with a single leaf only formed roots along the leaf axis at the base of the cutting. Quercetin increased the rooting percentage more than three times compared to the control and all flavonoids tested improved the distribution of roots around the stem without impacting the number of regenerated roots per rooted cutting from 20-year-old plants.     

Production of high quality Ardisia plants by stem tip cuttings

To produce commercially acceptable Ardisia plants, stem tip cuttings from mature plants were rooted and forced in greenhouses. Ten centimeter long cuttings were either treated with 200 ppm 1-naphthalene acetic acid (NAA) for 2 h, 2000 ppm indole-3-yl-butyric acid (IBA) for 10 s, or 0.5 and 1.0% IBA powder prior to sticking them in the rooting medium. Rooting percentage at 45 days exceeded 76% with 2000 ppm IBA treatment which was a significant increase over non-treated control. Rooted cuttings developed into three types of plants: those forming only vegetative shoots without flowers, those forming reproductive shoots with flowers, and those forming both vegetative and reproductive shoots. The ideal plant produced only vegetative shoots when rooted cuttings were transplanted into pots. About 50% rooted cuttings were forced to finish, producing 31 or 40% of high quality plants when rooted cuttings with vegetative shoots were grown in a greenhouse (GH) at temperatures higher than 21/19 °C (day/night) in 1995 or 21/18 °C GH in 1997, respectively. This method shortened the total production time to less than 2 years as compared to 4 years when starting from seeds.     

Flowering influences adventitious root formation in chrysanthemum cuttings

Root formation in chrysanthemum (Dendranthemum grandiflora (Ramat.) Kitamura) cuttings was reduced as flowers developed on stock plants. This effect was shown for all ten cultivars evaluated in this study. Not all cultivars were affected equally by the presence of flower buds on cuttings. There was no relationship (r² = 0.06) between root formation in vegetative cuttings and the ability for a cultivar to root from flowering cuttings. IBA (1 mM) could partially overcome the negative effect of flowering on root formation, but cuttings taken after the flower buds had fully opened failed to root even after auxin treatment. Removing buds from cuttings or continually removing flower buds during stock plant growth reduced rooting compared to cuttings with flower buds intact. Furthermore, cuttings taken from the top three nodes of the stock plant containing flower buds rooted comparably to cuttings taken from the lower stem section that contained only vegetative buds. The negative influence of flowering on root formation appears to be due to the photoperiodic induction of the flowering stimulus rather than a direct competition for resources between flowers and developing roots.     

美丽翠雀的茎枝扦插研究

 美丽翠雀( Delphinium‘Schloss Wilhelmschohe’) 可在春、夏季用茎枝进行扦插繁殖。切取新生茎枝顶端12～15 cm枝条为插穗, 用IBA 5～10 mg·L^-1浸泡基部1 h 后在珍珠岩∶腐叶土∶粗砂= 1∶1∶2 (体积比) 的基质上扦插效果较为理想。     

Propagation temperature,PPFD, auxin treatment,cutting size and cutting position affect root formation,axillary bud growth and shoot development in miniature rose (Rosa hybrida L.) plants and alter homogeneity

Summary

Rooting and growth responses of miniature rose cuttings were investigated in an experiment in which four propagation temperatures, two photosynthetic photon flux densities (PPFDs) with five auxin (IBA) concentrations, cutting sizes and cutting positions, were combined factorially in a response-surface design. Most prominently, temperature, cutting size and auxin and their interactions, influenced root and shoot growth. A propagation temperature of 24.6°C, and IBA concentrations between 10^–3 and 10^–1M, depending on temperature, were optimal for root formation. Root formation in extra short cuttings was delayed at low IBA concentrations. Regarding root formation, IBA could substitute for increased temperature as well as for increased cutting size. Onset of axillary bud growth was fastest at 24.6°C, and delayed in extra short cuttings. Application of IBA at 10^–4 to 10^–3M was optimal for axillary bud growth. By increasing the IBA concentration both time to flowering and plant height increased at 24.6°C. In cuttings from higher positions on stock plants, axillary shoots enhanced their growth to flowering, became shorter, and weighed less, suggesting occurrence of positional effects (topophysis). The growth rate increased with increasing IBA concentration, as well as from medial to low positioned cuttings. Increasing propagation PPFD from 46 to 72 µmol m^–2s^–1 did not affect the parameters. Time to axillary bud growth and time to first flower were related to time-to-visible root. Fast formation of roots apparently resulted in fast axillary bud growth. In time-to-visible root and axillary bud growth, the smallest variation between plants was found at optimal ranges for temperature, IBA concentration and cutting size, and further factors optimal for root formation and axillary bud growth provided the most synchronized plant development.     

Effect of light,temperature and CO2 on the growth of Campanula isophylla stock plants and on the subsequent growth and development of their cuttings

Stock plants of Campanula isophylla Moretti were subjected to different temperature and light conditions and to various CO₂ regimes. The number and the fresh and dry weight of the cuttings produced were recorded. The after-effect of stock-plant treatment on root formation and growth of cuttings was studied.Increasing light intensity and CO₂ supply strongly promoted cutting production and increased both fresh and dry weight of the cuttings. These factors also markedly influenced root formation and root growth of the cuttings. Stock plant conditions also strongly influenced the growth and lateral shoot formation of the rooted cuttings. It is concluded that cuttings from stock plants grown under favourable light (10 Klx) and CO₂ conditions (900 v.p.m.) contain factors beneficial for root formation, growth and shoot formation. The results are discussed in relation to the carbohydrate content of the cuttings.     

Root formation,bud growth and survival of ornamental shrubs propagated by cuttings on different planting dates

Summary

Semi-hardwood cuttings of Cornus alba ‘Sibirica’, Deutzia ‘Mont Rose’, Forsythia × intermedia ‘Lynwood’, Ligustrum vulgare ‘Liga’, Philadelphus × virginalis, Potentilla fruticosa ‘Goldfinger’, and Spiraea × vanhouttei were planted on seven dates from July to October in two years and at three locations to investigate the effect of planting date on root formation, axillary bud growth, and plant survival. Cuttings were planted directly in the field and covered with polyethylene. Generally, root formation, bud growth, and plant survival were similar both years and at the three locations. All species except Deutzia had relatively constant rooting percentages at planting dates until mid August. For all species rooting percentages declined from mid August to October. Except for Deutzia, plant survival the following spring was constant or decreasing with planting date. For all species except Potentilla axillary bud growth and survival of cuttings planted in late September or October tended to increase while rooting percentages continued to decrease. In all species there was a close relationship between axillary bud growth and survival. Results revealed that many roots per cutting accelerated axillary bud growth.     

不同基因型梨叶片离体培养和植株再生

 以‘巴梨’、‘身不知’和‘早酥’梨试管苗叶片为外植体, 对不定芽进行了诱导、增殖和生根。重点探讨了基本培养基、植物生长调节剂配比、AgNO₃ 不同浓度和NH4⁺-N与NO3^--N比例对不定芽再生的影响。结果表明, MS + TDZ 0.5 mg/L + IBA 0.1 mg/L为‘巴梨’叶片不定芽发生的最佳培养基。在QL + TDZ 1.0 mg/L +NAA 0.1 mg/L培养基上, 暗培养3周后转光下培养, ‘身不知’和‘早酥’分别获得89.6%、81.2%的不定芽再生率和3.45、3.73的平均再生芽数; 对‘巴梨’和‘早酥’不定芽再生有效促进的AgNO₃ 浓度范围为0.1～0.5 mg/L, 0.1～4.0 mg/L的AgNO₃、1∶2～7的NH₄⁺-N∶NO ₃^--N和21.50mmol/L的K+对‘身不知’叶片再生均有促进作用, 缺乏NH₄⁺-N不利于不定芽的再生; 转移到MS+BA1.0 mg/L + IBA 0.1 mg/L培养基上能快速增殖; 在MS、1 /4MS + IBA 1.0～2.5 mg/L +蔗糖5～15 g/L +活性炭0.5～1.0 g/L上获得了不同程度的生根苗。     

Nitrogen deficiency increases basal branching and modifies visual quality of the rose bushes

Rosebush architecture resulting from the spatial organisation of the plant axes induces plant shape and consequently within ornamental horticulture context, its visual quality and commercial value. This architecture can be modulated by environmental conditions, particularly in the horticulture context in which the possibilities to control growing conditions are numerous. The objectives of the study were to determine, in young rose bushes, (1) whether short periods of nitrogen deficiency affect branching and (2) whether this effect is sufficient to modify the visual quality of the plant in a sustainable manner. Between vegetative bud burst and the petal colour visible stage of the generated primary branch, young rooted cuttings of bush rose (cv Radrazz) were subjected to one of three nitrogen regimes: (1) no nitrogen deficiency, (2) continuous nitrogen deficiency, i.e. 35 days of N deficiency, and (3) nitrogen deficiency restricted to the flowering stages, i.e. 18 days of N deficiency. After the petal colour visible stage, all three groups of plants were supplied continuously with nitrogen. We observed the morphology of the axes and the kinetics of axillary bud burst. Twelve weeks after the petal colour visible stage, the visual quality of the rose bushes was evaluated by an expert jury. We found that nitrogen deficiencies (1) increased bud burst ratios in the medial and basal zones of the primary branch, (2) delayed the bud burst in the apical zone of the primary branch and (3) had long-term effects on plant visual quality. The continuous nitrogen deficiency regime produced flatter, more asymmetric and less vigorous rose bushes than the no nitrogen deficiency regime. By contrast, nitrogen deficiency during the flowering stages only resulted in more symmetric, taller and more vigorous rose bushes than the no nitrogen deficiency regime. Based on these results, the role of nitrogen on bud burst was discussed and candidate processes at the origin of the visual quality modification were suggested. This new approach combining ecophysiology and sensory assessment of ornamental plants enabled the identification of some early architecture components to be correlated with later visual quality characteristics and then to better target the physiological processes of interest.     

Rooting of chrysanthemum cuttings. Influence of irradiance during stock plant growth and of decapitation and disbudding of cuttings

Stock plants of Chrysanthemum morifolium Ramat. cultivar ‘Improved Mefo’ were grown in a controlled-environment room at different levels of irradiance (9, 23, 53 or 90 W m^?2). After 3 weeks, cuttings were excised and rooted for 3 weeks at an irradiance of 16 W m^?2. Cuttings from stock plants grown at the highest irradiance had the highest number of roots, while cuttings from the lowest irradiance had the lowest number of roots.The importance of the presence of shoot meristems for root formation was investigated through disbudding and decapitation at different times after the excision of the cuttings. Removing the buds on the day of excision had no effect on the number of roots formed, while the removal of the buds on day 2 to day 5 after excision had a promotive effect. Removal later than 7 days after excision had no effect at all.The results are discussed from the point of view that an interaction between nutritional and hormonal factors regulates the process of root formation.     

Influence of endogenous IAA levels and exogenous IBA on rooting and quality of leafy cuttings of Prunus ‘GiSelA 5’

Summary

The influence of exogenously applied indole-3-butyric acid (IBA) on root and shoot development of leafy cuttings was analysed in Prunus cerasus P. canescens ‘GiSelA 5’, a dwarfing cherry rootstock, in two successive years. Compared to control cuttings, IBA application (4 g l^–1 in 2003; 2.5 g l^–1 in 2004) caused higher indole-3-acetic acid (IAA) accumulation in the cutting bases, but that did not influence the percentage of rooted cuttings, nor their survival in either year. However, IBA inhibited callus formation and, consequently, influenced the quality of the developed cuttings. Callus formation impeded root development, reducing the number of main roots, and inhibited the growth of the cuttings, reducing the average total length of shoots formed by individual cuttings. Callus formation was most reduced in the cuttings in the second experimental year, with high initial IAA concentrations.     

The effectof daylength and supplementary lighting on the growth of Begonia × hiemalis leaf cuttings

No consistent differences in growth were observed between leaf cuttings of Rieger begonia ‘Schwabenland Red’ taken from stock plants grown under different daylengths.The effects of supplementary illumination, daylength and polythene-covering treatments applied during the 5-week propagation period were also small. Leaf size did not affect the subsequent development of the cutting, but large leaves trimmed to a size comparable to the smaller leaves rooted poorly and produced few shoots.After rooting, the young plants were very responsive to daylength. Under long days growth was rapid, but under short days a large percentage of the plants failed to regenerate. When shoots did appear on these plants, they were few in number and flowered precociously.     

Influence of cutting position and temperature during rooting on adventitious root formation and axillary bud break of Stephanotis floribunda

Stock plants were grown in a glasshouse under standard growing conditions. Single-node leafbud cuttings were excised and numbered according to the position on the stock plant. Rooting took place at basal temperatures of 17,20 or 23°C and at different durations at 17 or 20°C followed by 23°C. The rooting period lasted 9 weeks.

The temperature of 17°C for 9 weeks completely suppressed root formation. A temperature of 20°C was decisive for root formation. The optimal rooting temperature was higher than 23°C. Temperature treatments of 17 or 20°C for 2–4 weeks only suppressed rooting slightly compared with the 23°C treatment. Cutting position on the stock plant affected the number of roots formed per cutting but not the rooting percentage. Best rooting was observed in cuttings from the middle part of the stock plant.

Axillary bud break was accelerated with increasing rooting temperature and decreasing duration of the lower temperatures. With increasing cutting position number (numbered from top to base), axillary bud break was considerably delayed.

Temperature treatments which delayed root formation also delayed axillary bud break. On the other hand, the cutting position on the stock plant, which had only a minor effect on the speed of root formation, had a pronounced effect on the speed of axillary bud break.     

Stockplant factors affecting root initiation in cuttings of Triplochiton scleroxylon K. Schum., an indigenous hardwood of west africa

The ability of auxin-treated T. scleroxylon cuttings to root was affected by the prior management of potted stockplants. In undecapitated single-stem stockplants more cuttings from upper rather than lower mainstem nodes rooted; a difference paralleled by leaf water potential immediately after severance, although there was also a positive relationship with internode length. The rooting percentage of mainstem cuttings from unpruned stockplants ranged from 15% to 43% whereas that of cuttings from the lateral shoots of pruned stockplants ranged from 40% to 83%. Considerably more cuttings rooted from stockplants which were severely pruned than from those where decapitation removed only the top node; there seemed to be an inverse relationship with the number of shoots per plant and the carbohydrate: nitrogen ratio. However, in tall pruned stock- plants, more cuttings from lower lateral (basal) than from upper (apical) shoots rooted, although the differences between cuttings from basal and apical lateral shoots were less when the stockplants’ mainstems were orientated at 45° or kept horizontal, instead of vertically. Adding NPK 16 weeks before harvesting cuttings from 10-node vertical stockplants increased the rooting ability of cuttings from basal shoots without affecting the rooting of those from apical shoots. More lateral shoot cuttings rooted when two, instead of one or four lateral shoots were allowed to develop per stockplant, this being associated with less cutting mortality than occurred in pruned stockplants. In stock- plants with two shoots, cuttings from basal lateral shoots rooted better than those from apical shoots, although without competition from basal shoots. The rooting of apical shoots was enhanced by application of a complete fertilizer. The presence of basal shoots reduced the rooting ability of apical shoots even with the fertilizer application. Many of the effects of lateral branch position on rooting may be related to light intensity, for greater rooting percentages occurred among cuttings from lower, more shaded, than from upper less shaded branches. This positional effect was eliminated when branches were uniformly illuminated.     

The photoperiodic control of rooting,growth, and dormancy in Cornus alba L.

Cuttings from 2 cultivars of Cornus alba propagated in late September produced more and longer roots in long days (LD) than in natural days (ND). The effects of photoperiod on rooting were much less when cuttings were propagated in mid-August. LD during propagation in mid-August delayed the onset of leaf senescence and bud dormancy so that heavier and taller plants were obtained. Bud dormancy did not develop if the plants were grown under LD throughout the winter. Such treatment produced very tall plants and resulted in a greater proportion of their dry matter being distributed to the stems.Short-day (SD) treatment hastened bud dormancy development followed eventually by leaf senescence. Returning the plants to LD after more than 3 months of SD-treatment did not overcome the bud dormancy regardless of whether the plants still had leaves.It is recommended that if material of Cornus alba is propagated in August, the natural photoperiod should be extended during propagation so as to improve plant growth.     

Effects of time of collection,growing-conditions of mother plants and growth regulators on rooting of cuttings of Telopea speciosissima (Proteaceae)

Terminal stem cuttings of Telopea speciosissima were collected from two locations at monthly intervals and treated with indolebutyric acid (IBA) in combination with benomyl. Cuttings taken in the first half of spring, at the beginning of vegetative growth, gave the highest percentage of rooted cuttings and the greatest length of adventitious roots per rooted cutting. Cuttings taken from the environment most suited for the growth of the mother plants also produced the highest percentage of rooted cuttings, but their root length did not differ significantly between the two locations. Pre-treatment of cuttings with 4000 p.p.m. IBA (concentrated solution dip method) initially gave the highest percentage of rooted cuttings and longest root length, but there was evidence for a delayed toxicity to IBA applied at this level. Pre-treatment with 2000 p.p.m. IBA is therefore recommended.Benomyl increased the percentage of rooted cuttings, but did not affect root length, possibly due to its fungicidal rather than cytokinin activity.     

Mist propagation of peach and almond × peach hybrids

Several factors contributing to the successful rooting of stem cuttings of four peach clones and one almond × peach hybrid under intermittent mist were tested. With the almond × peach cross, leaf-bud cuttings were also tested.Severe cutting back of adult peach mother trees in winter favoured rooting of the cuttings, but less severe cutting back induced maximum roots per cutting.For short periods vermiculite was found to be a suitable medium. Sand alone or mixed with vermiculite or gravel gave poor results. Gravel alone or mixed with vermiculite was intermediate. For growing the rooted cuttings for a longer period, a mixture of perlite and peat was very suitable.A period of illumination of 3 h starting at midnight with incandescent light improved rooting of peach cuttings in August and October, but not in June.With cuttings obtained from old fruit-bearing peach trees highest rooting rates were obtained in July, but best root development occurred when rooting was carried out in October. In July rooting rate of basal cuttings was much higher than that of terminal ones. Success with leaf-bud cuttings (including a small branch piece) obtained from young mother trees of the almond × peach hybrid was only achieved at the end of May or in June.Dipping the base of peach cuttings in water before rooting was of advantage with one cultivar rooted in September, but of no advantage with another cultivar rooted in June.When the base of stem cuttings was dipped for a prolonged period in IBA solutions of various concentrations, highest rooting rates were obtained with 25–50 ppm IBA for peaches and with 200 ppm for the almond × peach hybrid. The addition of Phygon XL to this solution was of some advantage for peach cuttings. The concentration inducing maximum root development was higher than that required for maximum rooting and callusing. The optimal IBA concentration for rooting of almond × peach leaf-bud cuttings was 100 ppm.Penetration of the IBA into the leaf-bud cuttings reached a maximum 45 min a after floating them on a 100 ppm solution.Transplanting cuttings which had been rooted under mist was somewhat difficult; however, high rates of survival were obtained with cuttings planted in September which had developed a good root system.     

Depressing Effects of Virus Infection on Adventitious Root Production in Apple Hardwood Cuttings

Adventitious rooting in dormant hardwood cuttings of MM. 106 apple rootstock was depressed by latent infection with five viruses, viz. rubbery wood, stem pitting, epinasty and decline, chlorotic leaf spot and platycarpa scaly bark viruses.

Both the number of rooted cuttings and the number of roots per rooted cutting were reduced, and fewer unrooted cuttings remained alive, thus representing a further potential loss.

The production of shoots suitable for use as cuttings was decreased from infected hedges, as was the ability of cuttings subsequently to become established and grow in the nursery.     

Rooting potential in plum hardwood cuttings: II. Relationships between shoot variables and rooting in cuttings from different sources

There was a positive correlation between shoot length and the proximal diameter of the prepared cutting in stockplant sources of Prunus insititia ‘Pixy’ that had different rooting potential. The precise relationship depended on source, with shoots from a severely pruned micropropagated source, and those developing from the trunks of various stock- plants, usually being thinner for any given length than normal distal cuttings from pruned and non-pruned conventional source stockplants. To a large extent rooting percentage, root numbers and root length increased between sources as the overall ratio of proximal stem diameter to shoot length decreased. Cuttings from the relatively thick, short shoots of the unpruned source were among the poorest rooting, while those from the relatively thin, long shoots from the trunk, and from the micropropagated source, rooted best. This between-source effect reflected the fact that within the less ready rooting sources there was also a negative correlation between the proximal diameter of the cutting and its rooting ability. This relationship was lost progressively as the rooting potential of sources increased, thus giving no opportunity for a trend to occur in the trunk-derived cuttings from the micropropagated source where virtually all cuttings rooted.