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.     

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.     

Rooting of peach hardwood cuttings for the meadow orchard

In order to make peach meadow orchard systems feasible, the possibility of propagating peaches by hardwood cuttings and thus reducing the establishment cost of this extremely high-density planting system was examined.A medium temperature of 25°C was harmful to auxin-treated peach cuttings, but excellent rooting could be obtained at a temperature as low as 12°C. Further trials conducted under outdoor conditions in winter in the coastal plain of Israel, with a soil temperature of 12–14°C, did not show any effect of timing on rooting, providing the cutting was taken mature enough (after mid-November) and not later than about 6 weeks prior to bud break. In 30 days root initiation started. Although variations were found between cultivars, 1500 mg/l of indole butyric acid in a 5-second base-dip was found to act well with most cultivars. Good aeration was shown to be critical for good root formation. Leaving the cutting for 1 month in damp sand prior to planting in orchard soil was satisfactory. An area of a few hectares of commercial meadow orchards has already been established with this method.     

毛梾硬枝扦插和嫁接繁殖技术研究

分别对影响毛株扦插生根的插穗规格、母树年龄、基质种类、激素种类及浓度等因素和对影响嫁接成活的嫁接时间及砧木进行系统研究.结果表明:生长调节剂以200 mg/kg NAA处理插穗生根效果最好,生根率为33％;插穗以母树年龄为1 a生的枝条中部10 cm插穗的生根效果最佳;扦插基质以蛭石∶泥炭∶河沙比例为1∶1∶3最佳;夏季嫁接以红瑞木为砧木的成活率可达83％以上.     

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.     

Stock plant shading and rooting of dahlia cuttings

The effect of shading dahlia mother plants on rootability of cuttings was studied with three cultivars: ‘Choot Hashani’, ‘Orpheo’ and ‘Lavender Perfection’. Reducing natural light intensity by approximately 50% increased rooting percentage of ‘Orpheo’ cuttings, but did not affect rooting of the harder cuttings of ‘Lavender Perfection’. Shading stock plants during midday hours only caused internode elongation in ‘Orpheo’, but did not increase rooting. In ‘Choot Hashani’ the same shading treatment promoted rooting. Shading only the base of the cutting when still on the mother plant greatly promoted rooting percentage and mean number of roots per cutting. The reason for the variability in the response to shading is discussed and it is concluded that the shading effect is limited to the root initiation region. It is assumed that shading improves rooting by promoting the herbaceous character of the rooting region. Shading did not affect rooting of cuttings which remained woody in spite of shade.     

Nitrogen content determines adventitious rooting in Euphorbia pulcherrima under adequate light independently of pre-rooting carbohydrate depletion of cuttings

Root regeneration in shoot tip cuttings responds to graduated nitrogen (N) fertilization of stock plants. In pelargonium cuttings, reduced carbohydrate reserves caused by high N absorption by the donor plants and post-harvest storage of cuttings limit adventitious root formation, especially in low-light environments. In contrast, in chrysanthemum, similar carbohydrate reserves do not have this dominant effect on rooting capacity. The positive correlation between rooting capacity and internal N status is stable across a wide range of environments and is genotypically consistent for this species. However, the influence of N and carbohydrates on adventitious rooting of Euphorbia pulcherrima is unknown. We investigated the consequences of different N fertilization regimens applied to E. pulcherrima stock plants and cold and dark storage of the cuttings on N absorption, carbohydrate distribution, and rooting capacity of cuttings. Increasing time of stock plant cultivation with graduated N nutrition produced cuttings with N contents, ranging from 19 to 51 mg N g⁻¹ dry mass (DM). High N absorption resulted in low carbohydrate concentrations in cuttings, and subsequent storage decreased carbohydrate concentrations further, particularly in stems. Lower sucrose contents in leaves were correlated with reduced rooting of stored cuttings at a particular harvest date. However, despite the lower carbohydrate levels, root numbers and lengths correlated positively with internal N concentrations. These relationships remained stable in unstored and stored cuttings, even when overall rooting intensity was reduced under lower natural light during autumn. Multivariate regressions accounting for nitrogen content, sucrose content and daily light integral during rooting highlighted these relationships and explained up to 79% of rooting variances. We conclude N nutrition of stock plants and N absorption by cuttings are the dominant factors determining the rooting capacity of poinsettia when rooting occurs under sufficient light, as is commonly available during propagation. To maximize rooting capacity of poinsettia cuttings their nitrogen content should exceed a threshold of 40 mg N g⁻¹ DM.     

Accelerated rooting of carnation ‘Red Baron’ by temperature pre-treatment

Rooting of carnation cuttings was promoted by storage temperatures above 0°C with an inverse relationship between the level of temperature and the duration of the treatment. The effect of temperature on root dry weight was far more important than the effect of duration of storage. A long storage and a high temperature increased the incidence of Fusarium. Storage at temperatures lower than 13°C gave better results with auxin applied after storage, while temperatures higher than 13°C gave better results with a pre-treatment of auxin. During storage for 14 days at 9°C, the position of the cuttings had no clear effect on rooting. Horizontal storage, however, appeared to be unfavourable. Removal of 0.5 cm of the base of the stem after storage nullified the storage effect. Carbohydrates in the removed pieces decreased during storage, more so at 13°C than at 0°C. Anatomically, an acceleration of cell division at the base of the cutting was observed during storage at 9°C as compared to 0°C.At a commercial nursery, storage of cuttings for 12 days at 14°C improved rooting by 84% compared to storage at 0°C. The presented technique tends to shorten the expensive and vulnerable period from planting to rooting.     

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.     

芙蓉花优良品种的繁殖技术研究

研究了不同基质和不同植物生长调节剂对芙蓉花扦插繁殖的效应,以及嫁接时间、剪砧时间、砧穗组合对芙蓉花嫁接繁殖的效应。结果表明,6个抗病虫品种插穗的生根能力大小顺序为CDS-5>CDS-1>CDS-6>CDS-4>CDS-3>CDS-2。利用芽插技术可以提高CDS-2的扦插生根率。不同基质间插穗死亡率的差异不显著。以蛭石作基质进行扦插繁殖效果最好。腐殖土基质中插穗的生长势比其它基质好。3种植物生长调节剂处理对芙蓉花的扦插存活影响不显著。在夏季嫁接芙蓉花成活率高,剪砧宜在嫁接后10d左右进行。     

Induction of roots on jujube softwood cuttings using Agrobacterium rhizogenes

Summary

Cuttings from trees of jujube (Ziziphus jujuba Mill.), particularly mature ones, root with great difficulty. A greenhouse experiment assessed the effects of two strains of Agrobacterium rhizogenes (A4 and TR105) on softwood cuttings from two sources: ten year old trees of cv. Li and a tree approximately 40 years old of the cv. Contorta. The cuttings were collected and trimmed to 7.5 cm. Ten weeks after inoculation, both strain and source of cutting influenced visible symptoms of infection. Jujube cuttings were more responsive to TR105 than to A4, and the ‘Li’ cuttings were more responsive than ‘Contorta’ cuttings. Strain TR105 was very effective in increasing rooting percentages and root number. ‘Li’ cuttings had better rooting percentages, greater root number, and greater root length than did the ‘Contorta’ cuttings. Inoculation with A. rhizogenes may also possess great potential for promoting adventitious root formation in other difficult woody ornamental or fruit tree species.     

Effect of pretreatment of stock plants of mango with cycocel, ethrel and morphactin on the rooting of cuttings and air layers

07121978

Abstract

Pretreatment of stock plants with cycocel or ethrel induced rooting on cuttings and air layers of mango (Mangifera indica L.), a difficult-to-root fruit plant which normally does not regenerate roots. Application of IBA to the cuttings and air layers made from pretreated shoots improved rooting, cycocel pretreatment being more effective than ethrel. Morphactin pretreatment inhibited rooting, fully counteracting the auxin-induced rooting.     

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.     

糙叶杜鹃扦插技术及插条营养物质变化研究

以糙叶杜鹃半木质化茎段为材料,采用KIBA、KNAA和Hormodin对插穗进行处理并测定不同生根期内可溶性糖和全氮的含量。结果表明:快蘸液态KIBA(3 000mg/L)处理对插穗生根具有显著影响,处理后的插穗生根率为92.55%,达到极显著水平;较高的C/N比有利于插穗生根,在扦插生根过程中碳水化合物是插穗不定根形成和生长所需的营养物质,在插穗愈伤组织的形成和根原基的发生期需消耗一定的可溶性糖;高浓度的氮素不利于插条的生根。     

Effect of acid or base pretreatment on auxin response of Damask rose cuttings

Hardwood stem cuttings of Damask rose (Rosa damascena Mill.) were dipped in H₂SO₄ or NaOH prior to application of 0, 1000, 2000 or 3000 mg l⁻¹ indolebutyric acid (IBA) or naphthaleneacetic acid (NAA). Acid pretreatment significantly increased root number, root length and root dry weight per cutting, but did not affect rooting-percentage. Rooting was significantly enhanced by auxin pretreatment, and NAA was superior in increasing root length and root fresh weight; 2000 mg l⁻¹ of auxin was the most suitable concentration for promotion of rooting under the conditions of the study.     

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.     

Rooting response of shoot cuttings from three peach growth habits

Current year shoot cuttings were collected in October and August from three growth habits of peach (Compact, Pillar, and Standard) and treated with one of four concentrations of indole butyric acid (0, 250, 1250, and 2500 mg L⁻¹ IBA). Rooting response was measured after 5 weeks in the greenhouse. Little or no rooting occurred with cuttings from any growth habit that was collected in October or in August when treated with 0 and 2500 mg L⁻¹ IBA. In August, the number of shoots that rooted was greater in cuttings from Pillar (79 and 45%) than Compact (13 and 3%) treated with 250 and 1250 mg L⁻¹ IBA, respectively. Cuttings from Standard trees had intermediate rooting of 56 and 6% at 250 and 1250 mg L⁻¹ IBA, respectively. Pillar trees consistently grew more roots with greater root length per cutting than the other growth habits. It is proposed that differences in rooting response among the growth habits may be associated with differences in endogenous auxin concentration that had been found in previous studies. Within peach and possibly other fruit trees, the capacity of shoot cuttings to develop adventitious roots can vary by cultivar and successful root induction with exogenous plant growth regulators may depend, in part, on endogenous hormone levels.     

Rapid vegetative propagation of conifers

Factors influencing the rooting-potential of stem cuttings of conifers were studied for the purpose of improving methods of rapid vegetative propagation. Within the bounds of hereditary limits, root regeneration depends, to a considerable extent, on the qualities of rooting-media, date of cutting excision, age and physiological conditions of the stock plant, age of the cutting-wood, its position on the plant, and chemical treatment. Hardwood cuttings, which have a relatively high content of endogenous auxin and carbohydrates, and morphological root initials, gave the best results. This method made it possible to increase the growth rate of cuttings 2.5–5 times that of cuttings taken from shoots of current growth.     

毛梾硬枝扦插正交实验

在大田条件下通过正交实验L9(34),研究取穗部位、生长调节剂、生长调节剂浓度、处理时间4个因素对毛梾硬枝扦插的影响。结果表明:生长调节剂的影响极其显著,取穗部位和处理时间的影响显著,处理浓度的影响不显著,各因素的主次效应为生长调节剂处理时间取穗部位处理浓度,在大田条件下该次试验毛梾硬枝扦插最佳组合为:选用枝条中部的插穗,用200mg/L NAA+IBA(1∶1)混合生长调节剂浸泡2h进行试验。     

Contributions of the leaves and axillary shoots to rooting in Eucalyptus granáis Hill ex Maid,stem cuttings

In one-node stem cuttings of Eucalyptus granáis the absence of leaves was fatal. The optimum leaf area per leaf for rooting was 2-5 cm2, and in this range rooting was higher in one-leaf than in two-leaf cuttings. Axillary shoots started to develop soon after the cuttings were set and their growth was promoted by the presence of the subtending leaf. Thus, in one-leaf cuttings the shoot in the leafy axil grew, at the expense of the shoot in the defoliated axil, while in two-leaf cuttings the shoot in the upper (sub-opposite) axil tended to grow more quickly. Axillary shoots were also vigorous in cuttings from decapitated and disbudded mother plants. Rapid shoot growth was associated with low rates of abscission of the subtending leaf and relatively high rooting ability. Removing axillary shoots from cuttings accelerated leaf abscission and reduced rooting. The stem of the cutting often swelled and discoloured from the base, apparently due to the demand of the cutting for water. Additional leaf wounds had no effect on rooting (but increased mortality), while immersing cuttings in water before setting, or leaving them in a loose heap on the propagation bench, promoted rooting.