Application Of Indolebutyric Acid Research Articles

EFFECT OF DIFFERENT LEVELS OF I.B.A CONCENTRATION ON CLONAL PROPAGATION OF EUCALYPTUS SPECIES IN GHANA WEST AFRICA

Effective rooting and survival of cuttings has become more important owing to increased global wood demands and climate change. This study assesses the survival of ten (10) clones each of Eucalyptus grandis x Eucalyptus urophylla (E. grandis x E. urophylla) and Eucalyptus pellita (E. pellita) clonal cuttings when treated with different Indole-3-butyric acid (IBA) auxin concentrations of 0 ppm (control), 2000 ppm, 3000 ppm and 4000 ppm respectively. Overall, the mean survival of cuttings with respect to both species (10 clones each) was low (i.e < 50%) for all concentrations of IBA used. E. grandis x E. urophylla cuttings had the highest mean survival (43.39%) when treated with 2000 ppm of IBA and lowest mean survival (37.86%) when treated with 0 ppm. E. pellita (P) cuttings had the highest mean survival (27.14%) when treated with 2000 ppm of IBA. Individual clones however showed higher survival with respect to IBA treatments. Eucalyptus grandis x Eucalyptus urophylla clone (GH11) achieved a mean survival rate of 75% with 2000ppm of IBA. E. pellita clone P2 achieved its highest survival (52.68%) in the control experiment (0 ppm). Although IBA application had significant effect on cutting survival, parent material (individual clones) also plays a vital role in cutting survival as some clones such P51 and P82 achieved survivals of less than 10% given all four levels of IBA used. Individual clones also respond to IBA concentration differently. GH3 and GH10 had their highest survivals (i.e 66.07% and 61.61% respectively) in the control (0ppm of IBA). Results from this study can be used in plus tree clonal selection regimes to identify the best economically rewarding clones in terms of cutting survival to be used in forest plantation establishments.

\u03b3-Aminobutyric Acid Participates in the Adult-Phase Adventitious Rooting Recalcitrance

In many tree species especially the rooting-recalcitrant woody perennials, the adventitious root (AR) in the juvenile phase can be easily induced by exogenous auxin, but AR formation becomes recalcitrant in the adult phase. Also, it is reported that the γ-aminobutyric acid (GABA) inhibits primary root growth in Arabidopsis and the AR formation in poplar (Populus ssp). So far, how GABA affects or is affected by the ontogenetic phase or auxin remains unclear. Here, we used an apple rootstock, Malus xiaojinensis, and tobacco (Nicotiana benthamiana) to investigate this question. We first analyzed the content of GABA, the activity of GABA synthetic enzyme GAD, and the expression of the coding gene MxGADs, respectively, in leafy cuttings of juvenile and adult phase. Next, the effect of exogenous GABA on AR formation was examined in in vitro shoots of M. xiaojinensis and tobacco. Interestingly, significant and consistent increases in GABA concentration, GAD activity, and expression of MxGAD genes in response to exogenous indole butyric acid (IBA) were detected in adult-phase cuttings, but not in juvenile-phase cuttings. Exogenous GABA application inhibited the AR formation by delaying rooting time and reducing root number and the total root length in in vitro shoots of both M. xiaojinensis and tobacco. The expression of MxPIN members increased in response to IBA application, but these changes were restrained by the addition of GABA. These results indicate that both the loss of juvenility and IBA are required to trigger GABA accumulation. GABA may affect the AR formation as a co-actor by inhibiting polar auxin transport. Together, these findings facilitate the understanding of the regulatory network among GABA, juvenility, and auxin signaling on the AR formation.

Auxin and Its Interaction With Ethylene Control Adventitious Root Formation and Development in Apple Rootstock.

Adventitious root (AR) formation is indispensable for vegetative asexual propagation. Indole-3-butyric acid (IBA) functioned indirectly as precursor of IAA in regulating AR formation. Ethylene affects auxin synthesis, transport, and/or signaling processes. However, the interactions between auxin and ethylene that control AR formation in apple have not been elucidated. In this study, we investigated the effects of IBA and its interaction with ethylene on AR development in apple. The results revealed that IBA stimulated the formation of root primordia, increased the number of ARs, and upregulated expression of genes (MdWOX11, MdLBD16, and MdLBD29) involved in AR formation. Comparison of different periods of IBA application indicated that IBA was necessary for root primordium formation, while long time IBA treatment obviously inhibited root elongation. RNA-seq analysis revealed that many plant hormone metabolism and signal transduction related genes were differentially expressed. IBA stimulated the production of ethylene during AR formation. Auxin inhibiting ARs elongation depended on ethylene. Together, our results suggest that the inhibitory role of auxin on AR elongation in apples is partially mediated by stimulated ethylene production.

Indole-3-butyric acid priming reduced cadmium toxicity in barley root tip via NO generation and enhanced glutathione peroxidase activity.

Activation of GPX and enhanced NO level play a key role in IBA-mediated enhanced Cd tolerance in young barley roots. Application of exogenous indole-3-acetic acid (IAA) or an IAA precursor improves the tolerance of plants to heavy metals. However, the physiology of these tolerance mechanisms remains largely unknown. Therefore, we studied the priming effect of indole-3-butyric acid (IBA), an IAA precursor, on mild and severe cadmium (Cd) stress-induced responses in roots of young barley seedlings. IBA, similarly to mild Cd stress, significantly increased the glutathione peroxidase (GPX) activity in the apexes of barley roots, which remained elevated after the IBA pretreatment as well. IBA pretreatment-evoked high nitric oxide generation in roots effectively reduced the high superoxide level under the severe Cd stress, leading to less toxic peroxynitrite accumulation accompanied by markedly reduced Cd-induced cell death. On the other hand, the IBA-evoked changes in IAA homeostasis resulted in root growth reorientation from longitudinal elongation to radial swelling. However, the application of an IAA signaling inhibitor, following the activation of defense responses by IBA, was able to promote root growth even at high concentrations of Cd. Based on the results, it can be concluded that the application of IBA, as an effective activator of Cd tolerance mechanisms in young barley roots, and the subsequent use of an IAA signaling inhibitor for the inhibition of root morphogenic responses induced by altered auxin metabolism, results in a high degree of root Cd tolerance, helping it to withstand even the transient exposure to lethal Cd concentration without the absolute inhibition of root growth.

Ginkgo biloba L. mini-cuttings: indole butyric acid, substrates, and biochemical composition of the mother plants

The objective of this study was to evaluate the viability of the Ginkgo biloba mini-cutting technique, as well as the influence of substrates and different concentrations of indole butyric acid (IBA) on adventitious rooting in addition to the protein and sugar content in the mini-cutting. Mini-cuttings were 4 ± 1 cm in length, with the bases immersed in solutions of 0, 1000, 2000, and 3000 mg L-1 IBA. They were then planted in polypropylene tubes using two substrates (vermiculite and Tropstrato®) and maintained under greenhouse conditions for 60 d. The experiment was carried out with a 2 × 4 factorial scheme (substrates × IBA). There was no influence of IBA application on the promotion of rhizogenesis in Ginkgo biloba mini-cuttings. The rooting percentages were higher than 55% regardless of the treatment used. The vermiculite substrate showed a higher number of roots (4.94) and lower mortality (11.60) of mini-cuttings than Tropstrato®. We conclude that the mini-cutting technique is feasible for Ginkgo biloba, and the use of IBA is not necessary. We found that the induction ofadventitious rooting depended on the biochemical composition of the mother plants, due to the translocation of non-reducing sugars and leaf proteins for root formation.

Highly Successful Adventitious Root Formation of Zamia L. Stem Cuttings Exhibits Minimal Response to Indole-3-Butyric Acid

The influences of indole-3-butyric acid (IBA) concentrations of 0–30 mg·g−1 on the success and speed of adventitious root development of Zamia furfuracea L.f. and Zamia integrifolia L.f. stem cuttings were determined. Root formation success for both species was greater than 95%. The IBA concentrations did not influence the speed of root development for Z. furfuracea, but the Z. integrifolia cuttings that received IBA concentration of 3 mg·g−1 generated adventitious roots more slowly than the cuttings in the control group. The ending dry weights of the stems, leaves, and roots were not influenced by IBA concentration for either species. Our results indicated that adventitious root formation on stem cuttings of these two Zamia species is successful without horticultural application of IBA. Additional IBA studies are needed on the other 300+ cycad species, especially those that are in a threatened category.

Indole -3- Butyric Acid Induces Plant Regeneration From Stem Cuttings Of Three Medicinal Plants

Field regeneration of three (3) medicinal plants - Securidaca longepedunculata (violet tree), Ocimum gratissimum (scent leaf) and Pterocarpus mildebraedii by means of rooting of stem cuttings at different lengths of 10 -15 cm and 15 -20 cm were studied. The effect of the plant hormone Indole-3-Butyric acid (IBA) at 5g/l was tested on rooting, bud sprout and leaf formation of the rooted stem cuttings of the plant species as well as the effect of the length of the stem cuttings on their growth and survival rates. The results of the study revealed that stem cuttings of O. gratissimum treated with IBA and the control treatment sprouted within 5 - 8 days. The treated O. gratissimum stem cuttings produced a slightly higher number of buds (2.58 ± 0.86) when compared to the control (2.00 ± 0.89) with no significant difference at P ≤ 0.05. Stem cuttings of the treated P. mildbraedii cuttings sprouted within 8 -10 days with 1.40 ± 0.37 number of buds, with the control showing no sprouts. Consequently, IBA application produced more leaves (13.00 ± 5.58) and roots (1.33 ± 0.01) than the control. However, O. gratissimum stem cuttings had the highest leaf (13.08 ± 4.47) and root numbers (135.00 ± 13.45) followed by the control with values- 13.00 ± 5.58 for leaf development and 61.66 ± 2.34 for root number respectively. Irrespective of the treatments, none of the stem cuttings of S. longepedunculata sprouted. This study showed that exogenous application of IBA to stem cuttings of the tested plants, except S. Longepedunculata, improved the root number, number of leaves and number of buds.
 Keywords: Stem cuttings, Indole-3-Butyric acid (IBA), Rooting

Gentiana clusii Perr.&Song.: Enhanced production of secondary metabolites by in vitro propagation

Shoot and root in vitro culture of endemic European species Gentiana clusii was established for the first time. The effects of different concentrations of benzyl adenine (BA), 6-phurphurylaminopurine (KIN), indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA) on shoot propagation and rooting of G. clusii were investigated. The optimal in vitro conditions for shoot propagation and long-term maintenance were achieved using woody plant medium (WPM) supplemented with 0.5 mg l−1 KIN, and subsequent application of IBA at 0.5 mg l−1 significantly improved rooting of these shoots. Root culture was established from excised root tips cultured in ½ MS liquid media with increasing concentrations of IBA (0.1–1.0 mg l−1). A high root growth rate and considerable biomass yield were obtained by addition of 1.0 mg l−1 IBA. HPLC analysis revealed that in vitro culture considerably promoted the production of secondary metabolites in G. clusii. The selected protocol for shoot propagation (WPM + 0.5 mg l−1 KIN) increased the content of sweroside, gentiopicrin and norswertianin-1-O-primeveroside (N-1-P) for more than 2-fold compared with the wild plants. IBA promoted N-1-P and norswertianin production in root cultures; their contents were enhanced 6.4- and 18.6-fold, respectively, compared with the wild plants. The extract of these roots displayed the highest antioxidant capacity (IC50 = 66.57 μg ml−1). The established shoot and root propagation protocols facilitate in vitro conservation of G. clusii, and provides a promising tool for the large scale production of valuable secoiridoids and xanthones.

An efficient protocol for Cistus crispus L. (Cistaceae) micropropagation

Abstract Cistus crispus (Cistaceae) is a species adapted to arid and semi-arid conditions, and it has ornamental and medicinal uses. In Italy, native populations of C. crispus are threatened by the collection due to the low number of individuals in the populations, anthropogenic pressure, and the changing environmental condition that enhance other more aggressive and hybridisable Cistus species. Here, we set up the variables for its micropropagation protocols to achieve a high number of plants per unit time. Various steps of the micropropagation protocol were modulated, including various sodium hypochlorite concentrations (CHCs) and time of sterilisation. The efficiency of the protocol maximised at 25 min sterilisation with 2.5% CHC and decreasing explant vitality at increasing time and CHC. Both shoot proliferation and root emissions were maximised at 1.78 μM N-6-benzyladenine (BA) in the growing medium, with up to 5.4 explants per cycle, with 5.8 roots per explant, and 84 healthy explants. Kinetin stimulated further the axillary root proliferation more than dimethylallylamino purine or BA. Lastly, the application of indole acetic acid increased root emissions during the acclimation stage more than the application of indole butyric acid, and this occurred irrespective of their concentrations, up to 2.0 μg · g−1. These results can foster the use of C. crispus as an ornamental species, for xeriscaping or for the extraction of its secondary compounds, which have various industrial uses. These results can also have an indirect implication for the conservation of the species by reducing the collection for ornamental purposes from its natural population.

GERMINATION POTENTIAL AND VEGETATIVE PROPAGATION OF Aegiphila brachiata VELL

The objective of this study was to evaluate the germination potential of Aegiphila brachiata (peloteiro) and its propagation through stem-cuttings, as well as how the age of parental plants and the application indolebutyric acid (IBA) and inoculant of Azospirillum brasilense influence adventitious rooting of the species. Thus, the physical characterization of a seed lot and a germination test were performed, both with or without seed scarification and at three gibberellin concentrations (0, 50 and 100 mg.L-1 GA3). For stem-cuttings, two experiments were carried out with cuttings, one with young individuals and the other with adult trees. In both experiments, stem-cuttings were submitted to treatments with IBA (0, 1500, 3000 and 6000 mg.L-1) and a solution of Azospirillum brasilense (50% and 100% of the commercial concentration) for rooting in a greenhouse for 30 days. No seeds germinated and a barrier of radicle emission was identified in the endocarp. The inoculation of stem-cuttings with A. brasilense revealed no influence in rhizogenesis. The stem-cutting technique from young trees is recommended for plantlet production of this species (53.75% rooting), requiring 6000 mg.L-1 IBA application under the conditions that were adopted. Stem-cuttings from adult trees are not recommended for the production of plantlets of peloteiro (Aegiphila brachiata Vell.) due to the low rooting rates (10%) and high mortality (68.33%).

Rooted cuttings by IBA (Indole butyric acid) and NAA (Naphthalene acetic acid) in black pepper (piper nigrum) - A case study in Vietnam

In order to investigate the effect of IBA (Indole Butyric Acid) and NAA (Naphthalene Acetic Acid) on rooted cuttings, there were two experiments were conducted. The first experiment was two factor experiment where IBA and NAA were applied as different concentrations to main stems (cuttings). There were 14 treatments and 4 replications, including 20 pots/treatment; 1,120 pots in total. Similarly, the second was also two factor experiment consisted of IBA and NAA in different concentrations. The total of 800 pots were divided into 10 treatments and 4 replications. The results showed that application of IBA at concentrations of 5,000 ppm on cuttings showed highest plant parameters in terms of plant and root growth. On the other hand, rooting hanging shoots could be found at lower concentrations of IBA 300 ppm and NAA 400 ppm. It is concluded that IBA and NAA can be used in vegetative propagation to improve success rare and obtain better cutting growth.

Transcriptomic profiling and discovery of key genes involved in adventitious root formation from green cuttings of highbush blueberry (Vaccinium corymbosum L.)

BackgroundPropagation of cuttings is frequently used in various plant species, including blueberry, which shows special root characteristics that may hinder adventitious root (AR) formation. AR formation is influenced by various factors, and auxin is considered to play a central role; however, little is known of the related regulatory mechanisms. In this study, a comparative transcriptome analysis of green cuttings treated with or without indole-butyric acid (IBA) was performed via RNA_seq to identify candidate genes associated with IBA-induced AR formation.ResultsRooting phenotypes, especially the rooting rate, were significantly promoted by exogenous auxin in the IBA application. Blueberry AR formation was an auxin-induced process, during which adventitious root primordium initiation (rpi) began at 14 days after cutting (DAC), root primordium (rp) was developed at 21 DAC, mature AR was observed at 28 DAC and finally outgrowth from the stem occurred at 35 DAC. Higher IAA levels and lower ABA and zeatin contents might facilitate AR formation and development. A time series transcriptome analysis identified 14,970 differentially expressed genes (DEGs) during AR formation, of which there were 7467 upregulated and 7503 downregulated genes. Of these, approximately 35 candidate DEGs involved in the auxin-induced pathway and AR formation were further identified, including 10 auxin respective genes (ARFs and SAURs), 13 transcription factors (LOB domain-containing protein (LBDs)), 6 auxin transporters (AUX22, LAX3/5 and PIN-like 6 (PIL6s)) and 6 rooting-associated genes (root meristem growth factor 9 (RGF9), lateral root primordium 1 (LRP1s), and dormancy-associated protein homologue 3 (DRMH3)). All these identified DEGs were highly upregulated in certain stages during AR formation, indicating their potential roles in blueberry AR formation.ConclusionsThe transcriptome profiling results indicated candidate genes or major regulatory factors that influence adventitious root formation in blueberry and provided a comprehensive understanding of the rooting mechanism underlying the auxin-induced AR formation from blueberry green cuttings.

Penyimpanan Mahkota Nanas dan Zat Pengatur Tumbuh pada Pertumbuhan Setek Basal Daun Asal Mahkota

The availability of pineapple seedlings in the field is a problem in the development of Smooth cayenne pineapple because of limited sources of planting material compared to the other types. Effort that can be done to solve the problem is to use the method of crown leaf-bud cutting. Propagation of pineapple (Ananas comosus L) with the method of crown leaf-bud cutting is not optimum so it can be optimized; one of them is by giving the duration of storage treatment and application of plant-growth regulators. The experiment was aimed to study the effect of crown storage duration and plant growth regulators on the growth of pineapple seedlings. The experiment was arranged in a nested plot design. Duration of crown storage for 2 (control), 10, and 20 days in room conditions at a temperature of 29-35°C and humidity of 46-70% as the main plot. The subplot was combination of indole-3-butyric acid (IBA) and 6-benzylaminopurine (BAP) with the concentrations: IBA 300 ppm and BAP 400 ppm, IBA 300 ppm and BAP 600 ppm, IBA 400 ppm and BAP 400 ppm, as well as IBA 400 ppm and BAP 600 ppm. The results of the experiment showed that the leaf-bud cuttings which stored for 10 days 57.34% were survived, 57.15% were sprouted, and 51.62% were rooted, while the control that survived, sprouted, and rooted did not reach more than 30%. The content of endogenous ABA in the crown leaf-bud shoots decreased significantly after being stored for 10 and 20 days, while the contents of endogenous auxins and cytokines were not different from the controls. Application of IBA 400 ppm combined with BAP 400 and 600 ppm increased the percentages of survived and sprouted cutting 1.5-1.7 times compared to control. Keywords: auxin, cytokines, exogenous hormone, endogenous hormone, vegetative propagation

Effects of Substrate and Exogenous Auxin on the Adventitious Rooting of Dianthus caryophyllus L.

In this study, Dianthus caryophyllus L. was used as the experimental plant to investigate the effects of rooting substrate and exogenous auxin concentration on the adventitious rooting of the stem cuttings. Our results showed that the formulated substrates with different physicochemical properties significantly affected the root formation. The substrate with a ratio of cocopeat to perlite at 1:1 (v:v) resulted in the optimum rooting of D. caryophyllus cuttings. Different Indole-3-butyric acid (IBA) and 1-naphthalene acetic acid (NAA) concentrations affected the rooting percentage and seedling rate of D. caryophyllus. Application of NAA at 1000 mg·kg−1 with IBA at 100 mg·kg−1 resulted in the greatest rooting percentage and improved breeding speed. The rooting percentage and seedling rate did not increase with the increase in auxin concentration. Based on these results, we concluded that an appropriate rooting substrate is required to fulfill proper rooting of D. caryohhyllus cuttings, whereas an exogenous application of IBA and NAA at 1000 mg·kg−1 and 100 mg·kg−1 promoted the rooting and a higher auxin concertation inhibited rooting.

Variability and relationships among rooting characteristics for white poplar hardwood cuttings

White poplar is a key species in wood production and afforestation, but also very important for biodiversity preservation and habitat improvement. Vegetative propagation from hardwood cuttings is the most desirable method of white poplar breeding. The present research analyzed the effect of various technological treatments on four white poplar clones. Selected treatments were powder formulations of indole butyric acid (IBA) and foliar treatment with urea. The variability of 14 morphometric characteristics on the rooting of cuttings was analyzed, as well as relationships between them. Differences in analyzed morphometric characteristics depended on genotype, while the effect of the examined technological treatments was detected only by Fisher?s least significant difference (LSD) test. Significant variability between genotypes was found for traits describing rooting at the basal cut (R0 and R0p), the number of leaves (LN), the total number of roots (TRN), and cutting survival in the first part of the growing season (SURV07). Application of IBA had significant stimulating effects on rooting at the lower part of cuttings (R05) compared to controls. Variability between genotypes after foliar treatment with urea was not detected. The examined parameters were grouped into 5 groups by principal component analysis, where shoot traits and traits that describe rooting at the basal cut were in the same group with total number of roots, and cutting survival (SURV07) was in a separate group. These results suggest a need for further testing of the characteristics of hardwood cuttings in white poplars. More efficient clone technology is needed, using auxins and/or nitrogen fertilization designed to suit the specific requirements of particular clones.

Collection period and indolebutyric acid on the rooting of adult pecan plant cuttings

Abstract: The objective of this work was to evaluate the effect of the collection period and of the exogenous application of indolebutyric acid (IBA) on the rooting of cuttings from adult pecan (Carya illinoinensis) plants. The experiment was carried out in a greenhouse with intermittent mist irrigation, from December 2017 to October 2018. The experimental design was completely randomized, in a 4x5 factorial arrangement, with four collection periods (spring, summer, autumn, and winter) and five concentrations of IBA (0, 2,000, 4,000, 6,000, and 8,000 mg L-1). For the cuttings collected during summer and autumn, there was a linear relationship between rooting and the increase of the IBA concentration. The best results for rooting, callus formation, mean number of roots, mean root length, and root dry and fresh mass are obtained for the cuttings collected during summer, with the application of 8,000 mg L-1 IBA on the base of each cutting, under a mist irrigation system. The rooting of cuttings from adult pecan plants with the application of IBA is possible, being an alternative propagation method for the species.

Rooting of herbaceous cuttings of Malpighia emarginata D.C. (CAMB-06 and APU-04 selections) associated with the use of indolebutyric acid and liquid extract of Cyperus rotundus L.

Abstract The objective of this work was to evaluate the rooting of herbaceous cuttings of CAMB-06 and APU-04 acerola cherry selections associated with the use of indolebutyric acid (IBA) and a concentration of aqueous extract of coco-grass. Cuttings were treated by immersion with different concentrations of IBA (0; 1,000; 2,000; 3,000; 4,000 mg L-1) and one application of aqueous extract of coco-grass in proportion 100% and placed to root in plastic boxes containing vermiculite. The experimental design was a completely randomized in a 2×6 factorial arrangement (two acerola cherry selections and six solutions for rooting) with four replicates of ten cuttings. After 90 days of cutting, the following variables were evaluated: cutting survival (%); leaf retention (%); rooted cuttings (%); sprouting (%); number of roots per cutting (%); length of roots (cm) and dry mass of roots per cutting (g). It was concluded that the application of IBA at 4,000 mg L-1 presented a better root development, resulting in a higher percentage of rooted cuttings and higher number and dry mass of roots in relation to IBA at 0 mg L-1 for CAMB-06 selection, while the APU-04 selection can be efficiently multiplied by herbaceous cuttings without the use of IBA. Under the conditions that the trials was conducted, the application of 100% aqueous extract of coco-grass was not effective in promoting the rooting of cuttings of CAMB-06 and APU-04 acerola cherry selections.

Optimized cutting of yellow passion fruit and its potential for unstaked or trellised cultivation

Abstract: The objective of this work was to evaluate types of cuttings, indole-3-butyric acid (IBA) concentrations, and potting media on the rooting of passion fruit (Passiflora edulis) cultivars, and to compare the initial performance of flowering-competent cuttings cultivated in a trellising system or in a nonstaking method on ground covered with plastic mulch. The passion fruit cultivars evaluated were BRS Gigante Amarelo, Isla Redondo Amarelo, and FB 200 Yellow Master were evaluated. The assessed treatments were: softwood or semi-hardwood cuttings; five concentrations of IBA (0, 500, 1,000, 2,000, and 4,000 mg L-1); and the pine bark or phenolic foam potting media. Initial growth, fruit yield, and bacteriosis severity were evaluated in the field in flowering-competent cuttings and seedlings, both in the trellising system and in the nonstaking method on mulched ground. For the evaluated cultivars, a high rooting rate (>90%) was observed for both softwood and semi-hardwood cuttings grown in phenolic foam or decomposed pine bark for potting media, regardless of the IBA concentration. In the espalier system, 14 months after transplanting, fruit yield was 45% higher for cuttings than for seedlings. Unstaked plants had a low number of flowers and fruit set, and a great damage by bacteriosis according to the used cultivar. The evaluated cultivars can be propagated either by softwood or semi-hardwood cuttings, in phenolic foam or decomposed pine bark, without IBA application. Flowering-competent cuttings have the potential to anticipate the production in the trellised cultivation of yellow passion fruit.

Propagation of yellow mombin by stem and root cuttings treated with indolebutyric acid

Yellow mombin is a fruit species of growing interest in the agro-industrial sector, mainly in the North and Northeast regions of Brazil, although its commercial exploitation is still limited due to the lack of information regarding its propagation, among other factors. In this perspective, this work aimed to study the effect of the application of indolebutyric acid (IBA) in the vegetative propagation of yellow mombin by stem and root cuttings. The experiments were conducted in a plant nursery, under a completely randomized experimental design consisting of six concentrations of IBA (0, 1000, 2000, 3000, 4000 and 5000 mg.kg-1 in industrial talc), four replications, and ten cuttings per plot. The stem cutting experiment also evaluated the effect of the types of cuttings (tanchan, basal, stratified basal, medial, and apical), with the material being collected from a yellow mombin tree in full vegetative growth. The root cuttings were collected from a matrix plant in the stage of vegetative rest and cut into 15 cm length segments. After 120 days, the following variables were evaluated: percentage of living, sprouted, rooted, and calloused cuttings, and dry mass of roots and sprouts. The cuttings of the tanchan type showed higher survival and sprouting percentages, regardless of the concentration of IBA applied, whereas the rooting rate was low. The application of IBA increased the rooting percentage of the root cuttings until the maximum concentration of 5000 mg.kg-1, reaching 77.5%, although it did not influence the other variables analyzed. The root cuttings of yellow mombin exhibit good regeneration capacity.

Exogenous plant growth regulators improved phytoextraction efficiency by Amaranths hypochondriacus L. in cadmium contaminated soil

Phytoextraction assisted by plant growth regulators (PGRs) is gaining popularity in phytoremediation applications. A pot experiment was conducted to compare the effects of foliar applications of 11 PGRs, including Indole-3-acetic acid (IAA), Indole-3-butyric acid (IBA), diethyl aminoethyl hexanoate (DA-6), 6-Benzylaminopurine (6-BA), 1-naphthylacetic acid (NAA), Abscisic acid (ABA), 2,4-Dichlorophenoxyacetic acid (2,4-D), Ethrel (ETH), Brassinolide (BR), Gibberellin (GA3), and Compound sodium nitrophenolate (CSN) on plant development, chlorophyll content, antioxidant enzyme activities, Cd phytoextraction capacity and micro-distribution of Amaranthus hypochondriacus L. grown in Cd contaminated soil. The effect on biomass yield was dependent on the PGRs type, with IBA being the most efficient. The addition of PGRs increased Cd extraction efficiency, with their effect decreasing in the order: IAA > DA-6 > IBA > 2,4-D > 6-BA > NAA > BR > CSN > ETH > GA3 > ABA. Application of PGRs increased Cd concentrations in leaves and stems but reduction was found in roots (except for 2,4-D). Exogenous PGRs increased the activities of stress ameliorating enzymes (SOD and CAT) and led to a reduction in MDA (malondialdehyde) concentration. In leaves, scanning electron microscope-Energy dispersive spectrometer (SEM–EDS) confirmed that application of IBA or DA-6 further fixed more Cd in upper and lower epidermal cells, which might relate to more Cd migration from roots to shoots in Amaranthus hypochondriacus L. These findings suggest that the treatment with IBA or DA-6 appears to be optimal for enhancing the phytoextraction efficiency of Amaranthus hypochondriacus L. in Cd contaminated soil.