Adventitious Rooting Of Cuttings Research Articles

Enraizamento de estacas da baunilheira (Orchidaceae)

The vanilla plant (Vanilla planifolia) could have a higher commercial production but there are problems in the efficiency of propagation. The present work was conducted with the aim of studying the effect of different substrates, in the adventitious rooting of cuttings taken at five heights in the plant stem. The cuttings were 20cm long and had two buds and one leaf and were planted in: 1) Liquid medium formed by Clark’s nutrient added of 2.5mg L-1 of IBA placed in plastic foam box with a capacity of 1.5L lined inside with transparent plastic bag and lidded with proper lid. 2) Solid substrate formed by the mixture of sand, carbonized rice husk, soil and cured cow manure in equal proportions of volume, they being placed in rigid polypropylene with a capacity of 0.28L. 3) Pre-rooting of the cuttings in liquid medium (20 days before planting), and later transferred into seedling tubes containing solid substrate. The cuttings planted in the solid substrate were maintained under intermittent mist condition controlled by a timer. After 90 days, the percentage of rooting was of 98-100%, regardless of the treatment. Larger and more vigorous sproutings were obtained from cuttings planted directly into solid substrate. Adventitious rooting of cuttings and formation of new vanilla cuttings occurred, when the cuttings were obtained from position P2 (ranging between 20 to 40cm in stem height) and planted in solid substrate in greenhouse with intermittent misting system.

Relação do estado nutricional de minicepas com o enraizamento de miniestacas de eucalipto

O enraizamento adventício de estacas é influenciado por fatores intrínsecos e extrínsecos do material vegetal, e o conhecimento da ação deles é fundamental para o sucesso da produção de mudas por miniestaquia. O objetivo deste trabalho foi avaliar o grau de associação entre o estado nutricional das minicepas e o enraizamento de miniestacas de eucalipto, cultivadas em minijardim clonal em tubetes com subirrigação. Foram utilizados dados de enraizamento de miniestacas e teores de nutrientes quantificados pelas análises químicas dos tecidos foliares. A taxa de enraizamento foi correlacionada com o estado nutricional das brotações. Verificou-se que a nutrição mineral desempenha papel importante no enraizamento adventício de modo genótipo-dependente, ou seja, há diferença de comportamento dos clones em relação ao efeito dos nutrientes no enraizamento das miniestacas. Com relação ao teor de K, Ca, Mg e Mn, não foi observada associação com as taxas de enraizamento. Quanto aos demais nutrientes, em pelo menos um clone, houve associação positiva ou negativa entre as variáveis analisadas, com grau variável de acordo com o clone e o nutriente.

Piriformospora indica promotes adventitious root formation in cuttings

Adventitious root formation in excised plant shoots is a crucial process in the vegetative propagation of many plant species, and insufficient rooting causes substantial losses in the propagation industry. Based on the various physiological effects on whole plants described for the basidiomycete Piriformospora indica, it was hypothesized that inoculation of the substrate with this endophyte should promote the generation and growth of adventitious roots in cuttings. Inoculation experiments were conducted to study the effects of P. indica on adventitious rooting in three plant species. Inoculation with P. indica dramatically enhanced the number and length of the adventitious roots in pelargonium and poinsettia. Root colonization parameters suggest that the interaction between the endophyte and cuttings had already occurred before physical contact. In contrast, petunia showed no rooting response to P. indica inoculation. Very fast root formation in this plant indicates that a minimum time period for the fungus–plant interaction is required for establishment of a promoting effect. P. indica-based biotechnology is proposed as a new tool for improving plant propagation systems of plant species or cultivars with low to moderate capacity of adventitious root formation.

Peroxidases during adventitious rooting in cuttings of Arbutus unedo and Taxus baccata as affected by plant genotype and growth regulator treatment

Cuttings of Arbutus unedo (strawberry tree) and Taxus baccata (yew) were treated with 8.0 and 10.0 g l−1, respectively, of KIBA, IBA, IAA, NAA and Paclobutrazol. No rooting occurred without growth regulator treatment. The effect of growth regulators on percentage of rooting followed the order KIBA > IBA > IAA = NAA = Paclobutrazol = 0% (for A. unedo) and KIBA > IBA > IAA > NAA > Paclobutrazol = 0% (for T. baccata). Genotypes of the above plant species had significant effects on the number and length of roots, percentage of rooting and peroxidase specific activity (PA) on KIBA-treated cuttings. High PA seems to be related with low percentage of rooting in the case of A. unedo cuttings while no similar results were noticed in the case of T. baccata. Electrophoretic analysis revealed the appearance of two to three anionic and one cationic peroxidase isoforms in A. unedo cuttings, while six to nine anionic and no cationic peroxidases isoforms appeared in the case of T. baccata genotypes. During adventitious rooting, the PA showed the three interdependent phases (induction, initiation, expression) in both K-IBA treated cuttings of A. unedo and T. baccata, but in a different time course.

Activity and isoforms of peroxidases, lignin and anatomy, during adventitious rooting in cuttings of Ebenus cretica L.

Adventitious rooting of Ebenus cretica cuttings was studied in order to examine a) the rooting ability of different genotypes in relation to electrophoretic patterns of peroxidases. b) the activity and electrophoretic patterns of soluble and wall ionically bound peroxidases, the lignin content and anatomical changes in the control and IBA treated cuttings of <rooting> and <non-rooting> genotypes in the course of adventitious root formation. In addition, a fraction of soluble cationic peroxidases was separated by gel filtration chromatography from the total soluble peroxidases of a <rooting> genotype. No rooting occurred in cuttings without IBA-treatment. In both genotypes, electrophoretic patterns of soluble anionic peroxidases revealed two common peroxidase isoforms, while a fast-migrating anionic peroxidase isoform (A3) appeared only in <rooting> genotypes. Both genotypes showed similar patterns of soluble, as well as wall ionically bound cationic peroxidase isoforms. The number of isoforms was unchanged during the rooting process (induction, initiation and expression phase) but an increase in peroxidase activity (initiation phase) followed by decrease has been found in IBA-treated cuttings. During initiation phase the lignin content was almost similar to that on day 0 in <rooting> genotype while it was reduced at by about 50% in <non-rooting> genotype at the respective time. Microscopic observations revealed anatomical differences between genotypes. According to this study, the <rooting> and <non-rooting> genotypes display differences in anatomy, lignin content, activity of soluble peroxidases and the electrophoretic patterns of soluble anionic peroxidase isoforms. The A3-anionic peroxidase isoform could be used as biochemical marker to distinguish <rooting> and <non-rooting> genotypes of E. cretica and seems to be correlated to lignin synthesis in rooting process.

Distinct effects of auxin and light on adventitious root development in Eucalyptus saligna and Eucalyptus globulus.

Adventitious rooting is essential for vegetative propagation of woody species. We studied the effects of auxin and light on the development of adventitious roots in cuttings obtained from seedlings of Eucalyptus saligna Smith and E. globulus Labill in an attempt to characterize the adventitious rooting process and identify factors controlling rhizogenesis. Root development was scored as rooting percentage, root density (roots per rooted cutting), mean rooting time and root length. In both species, rooting time was reduced in the presence of auxin. Cuttings from 2-month-old E. saligna seedlings were responsive to lower auxin concentrations than comparable cuttings from E. globulus seedlings. Cuttings from 3-month-old E. saligna seedlings rooted promptly and rooting was not significantly affected by light conditions. In contrast, rooting of cuttings from 3-month-old E. globulus seedlings exhibited recalcitrant behavior and no roots were formed if illuminated during the root formation phase. Effective root regeneration of E. globulus cuttings was obtained by a 4-day exposure to 10 mg l(-1) IBA and culture in darkness during the root formation step. Loss of rooting capacity with seedling age was more pronounced in E. globulus than in E. saligna. The possibility of switching adventitious rooting off and on by manipulating light regime and exogenous auxin supply in E. globulus, and the constitutive nature of rooting in E. saligna may provide useful models for examining the rooting process at the biochemical and molecular levels in Eucalyptus.

Stimulation of Adventitious Rooting in Cuttings of Four Herbaceous Species by Piperazine

Piperazine, a chemical used as buffer component, greatly promoted adventitious root formation in cuttings of sunflower (Helianthus annuus L.), pea (Pisum sativum L.), mung bean (Vigna radiata L.) and to a lesser extent in bean (Phaseolus vulgaris L.) seedlings. Piperazine was more effective in acidic pH. The studies with piperazine analogues showed that any substantial modification of the structure caused the chemical to be less effective, or even inhibitory. Histological studies in sunflower hypocotyls demonstrated that piperazine did not alter the timing of the initial cell division. In the presence of piperazine, sunflower hypocotyls failed to develop primary phloem fibres. Piperazine at the concentrations that promote rooting did not kill or damage the tissue at the base of the hypocotyl. Compared to controls, piperazine treatment did not alter the proportion of primordia that eventually developed into actively elongating roots. Six days after treatment 45% of the control roots in the basal section were actively growing, compared to 51% in the piperazine. There was little evidence suggesting that the piperazine-induced promotion of rooting was caused by the removal of basal dominance in which piperazine killed the basal part of hypocotyl.

Endogenous Levels of Plant Hormones during the Course of Adventitious Rooting in Cuttings of Sequoiadendron giganteum (LINDL.) in vitro

Summary Root formation in Sequoiadendron giganteum cuttings from in vitro culture was accompagnied by at first a rise and then a fall in soluble peroxidase (EC 1.11.1.7) activity in the explant. A change in the opposite direction (a fall followed by a rise) was shown for free IAA as measured by a solid-phase enzyme immunoassay using specific anti-hormone antibodies. The levels of abscisic acid, zeatin and zeatin riboside estimated by similar immunological techniques increased up to the sixth day on the rooting medium, passed through a minimum on day 13 and then reincreased slightly. These variations were compared to those described in the literature. A scheme is presented showing the possible events connecting rooting and variations of endogenous plant hormones and isoperoxidases during rooting process of Sequoia.

Structure and development of adventitious roots in Salix caprea and S. caprea × S. viminalis

Formation and structure of adventitious roots in cuttings of two clones of S. caprea and a hybrid betwen S. caprea and 5. viminalis was studied with light microscopy (LM) and transmission electron microscopy (TEM). The hybrid contained large preformed root primordia, which in cuttings placed in water developed into roots in only three days. One of the S. caprea clones contained minute preformed root primordia, which developed into roots in about eight days. Treatment with indolebutyric acid (IBA) increased the percentage of rooted cuttings and the number of roots formed. Roots emerging from IBA‐treated cuttings contained both mature protophloem and protoxylem, while in roots of untreated cuttings only some sieve elements of the protophloem were mature. In the other 5. caprea clone no preformed root primordia were detected, but after treatment with IBA roots appeared in about two weeks. The cambium in treated stems produced a large number of cells, most of which differentiated into xylem. Root primordia were initiated in the newly produced tissue external to the cambium. The roots contained both mature protophloem and protoxylem at emergence. A few roots emerged also from extensive callus tissues formed external to the basal end of the cuttings. Cell enlargement and cell divisions in various parts of the base of the cuttings caused disruption of the peripheral tissues, which made the cuttings susceptible to infection by microorganisms.

Influence of a Crown-Gall Tumor Initiation Enhancer on Adventitious Rooting

Summary Present work demonstrates the interference of a tumor initiation enhancer present in extract fractions derived from highly susceptible plants and closely related to their competence for tumor formation, in adventitious rooting in cuttings and in intact mung bean plants. In intact plants the tumor initiation enhancer stimulates strongly the initiation of adventitious roots, but shows a much weaker effect on the growth of these initials. On the contrary, in cuttings this active compound(s) does not greatly influence the mean number of adventitious roots. A increase is only obtained if the active compound(s) is applied after an IBA treatment. One can conclude that the tumor initiation enhancer might have a function in triggering the cells opposite to the xylem poles, resulting in the initiation of the roots, but other factors (probably auxin) are involved in regulating the division and growth of the cells concerned. Similar mechanisms could be supposed for the regulation of the tumor initiation in dicotyledonous plants.

Abscisic Acid and the Rooting of Runner Bean Cuttings

Abscisic acid promotes the formation of adventitious roots in cuttings of Phaseolus coccineus L. The optimum concentration is 10-5 M. ABA antagonises the GA, induced inhibition of rooting. The ABA effect is accompanied by a stimulation of the growth of the 2nd internode. No ABA action is observed on cuttings kept continuously in the dark or on defoliated cuttings. Treatment of cuttings with ABA causes an accumulation of assimilates, especially sucrose, which are basipetally transported from the primary leaves to the basal parts of the cuttings.

Morphactin and Adventitious Root Formation in Pea Cuttings

AbstractStock plants of pea (Pisum sativum L. cv. Alaska) were grown at different controlled levels of irradiance (4, 16 or 38 W m−2) for 11 days from sowing. Morphactin (CFM, methyl‐2‐chloro‐9‐hydroxy‐fluorene‐9‐carboxylate) was applied to the apex of the stock plants 3 days before cuttings were excised. The cuttings were rooted at 16 W m−2. High levels of morphactin (&gt;5 × 10−3 mg l−1) inhibited root formation in the cuttings. Low concentrations of CFM (5 × 10−5 mg l−1) promoted the formation of adventitious roots in cuttings from plants grown at all three levels of irradiance, with the most pronounced effect in cuttings from 4 W m−2. Measurements of ethylene evolution by CFM‐treated plants 3 days after application, revealed a stimulatory effect on ethylene production by high CFM concentrations.

Action de la 2-thiouracile sur la rhizogen�se dans les boutures de plantules �tiol�es de tomate

1. 2-Thiouracil inhibits hypocotyl growth, adventitious root formation and growth of adventitious roots in cuttings of etiolated tomato seedlings. 2. The inhibition of the growth of hypocotyl was reversed totally by uracil and cytosin, but only partially by orotic acid and thymine. 3. The inhibition of the growth of adventitious roots was reversed by orotic acid, uracil and cytosine, but not by thymine. 4. The inhibition of adventitious root formation was reversed neither by orotic acid nor by uracil, cytosine, or thymine. 5. A hypothesis based on data in the literature is proposed to explain this latest results.

Origin and development of adventitious roots in cuttings of Chamaecyparis obtusa

Origin and development of adventitious roots in cuttings of <i>Chamaecyparis obtusa</i>