NAA Treatment Research Articles

In Vitro Regeneration Of Anthocephalus Cadamba From Nodal Explant

Micropropagation of Anthocephalus cadamba, one of the tropical trees and also includes a medicinal plant, has been cultured using nodal explants. The results in general, showed that the growth of jabon’s shoot in in vitro culture is influenced by the interaction between BAP and NAA. The addition of BAP at a higher concentration than NAA could stimulate shoot formation. Whereas, the addition of sole NAA stimulated the root formation. The highest shoots number (6 shoots/explant) was obtained on the basal medium of Murashige and Skoog supplemented with 5µM BAP and 2µM NAA for 90 DAP. In addition, from several treatments, there were several explants that grew roots that appeared at 56 DAP in the MS + 0µM BAP + 2µM NAA treatment. On that treatment as well, there were also roots with the highest average of 1.5 roots per expansion with an average length of 2.1cm.

Parthenocarpy-related genes induced by naphthalene acetic acid in oil palm interspecific O × G [Elaeis oleifera (Kunth) Cortés × Elaeis guineensis Jacq.] hybrids.

Parthenocarpy is the development without fertilization of seedless fruits. In the oil palm industry, the development of parthenocarpic fruits is considered an attractive option to increase palm oil production. Previous studies have shown the application of synthetic auxins in Elaeis guineensis, and interspecific O×G hybrids (Elaeis oleifera (Kunth) Cortés × E. guineensis Jacq.) induces parthenocarpy. The aim of this study was to identify the molecular mechanism through transcriptomics and biology system approach to responding to how the application of NAA induces parthenocarpic fruits in oil palm O×G hybrids. The transcriptome changes were studied in three phenological stages (PS) of the inflorescences: i) PS 603, pre-anthesis III, ii) PS 607, anthesis, and iii) PS 700, fertilized female flower. Each PS was treated with NAA, Pollen, and control (any application). The expression profile was studied at three separate times: five minutes (T0), 24 hours (T1), and 48h post-treatment (T2). The RNA sequencing (RNA seq) approach was used with 27 oil palm O×G hybrids for a total of 81 raw samples. RNA-Seq showed around 445,920 genes. Numerous differentially expressed genes (DEGs) were involved in pollination, flowering, seed development, hormone biosynthesis, and signal transduction. The expression of the most relevant transcription factors (TF) families was variable and dependent on the stage and time post-treatment. In general, NAA treatment expressed differentially more genes than Pollen. Indeed, the gene co-expression network of Pollen was built with fewer nodes than the NAA treatment. The transcriptional profiles of Auxin-responsive protein and Gibberellin-regulated genes involved in parthenocarpy phenomena agreed with those previously reported in other species. The expression of 13 DEGs was validated by RT-qPCR analysis. This detailed knowledge about the molecular mechanisms involved in parthenocarpy could be used to facilitate the future development of genome editing techniques that enable the production of parthenocarpic O×G hybrid cultivars without growth regulator application.

Genome-Wide Identification and Expression Analysis of the Aux/IAA Gene Family of the Drumstick Tree (Moringa oleifera Lam.) Reveals Regulatory Effects on Shoot Regeneration

Auxin plays a critical role in organogenesis in plants. The classical auxin signaling pathway holds that auxin initiates downstream signal transduction by degrading Aux/IAA transcription repressors that interact with ARF transcription factors. In this study, 23 MoIAA genes were identified in the drumstick tree genome. All MoIAA genes were located within five subfamilies based on phylogenetic evolution analysis; the gene characteristics and promoter cis-elements were also analyzed. The protein interaction network between the MoIAAs with MoARFs was complex. The MoIAA gene family responded positively to NAA treatment, exhibiting different patterns and degrees, notably for MoIAA1, MoIAA7 and MoIAA13. The three genes expressed and functioned in the nucleus; only the intact encoding protein of MoIAA13 exhibited transcriptional activation activity. The shoot regeneration capacity in the 35S::MoIAA13-OE transgenic line was considerably lower than in the wild type. These results establish a foundation for further research on MoIAA gene function and provide useful information for improved tissue culture efficiency and molecular breeding of M. oleifera.

PENGARUH KOSENTRASI NAA DAN TDZ (THIDIAZURON) TERHADAP ORGANOGENESIS KALUS KENCUR (Kaempferia galanga L.)

The production of kencur (Kaempferia galanga L.) with tissue culture is an alternative in kencur plant cultivation as a provider of seeds. In tissue culture, growth regulators can affect the formation of plant organs (organogenesis). The combination of growth regulators NAA and TDZ was used in this study to induce callus kencur organogenesis. The purpose of this research was to determine the effect of giving NAA and TDZ on the organogenesis of kencur callus, as well as the optimal combination of the two in the organogenesis of kencur callus. The design used was factorial RAL with two factors: NAA (0; 0.5 and 1 ppm) and TDZ (0; 2 and 4 ppm). Observation variables included number of shoots, shoot length, number of leaves, leaf length, number of roots, root length, fresh weight, and the first time shoots appeared. The results showed that the single NAA treatment affected the number of shoots, number of leaves, number of roots, root length, and fresh weight. In comparison, the single TDZ treatment affected shoot length, leaf length, number of roots, root length, and fresh weight. The optimal treatment combination was 1 ppm NAA and 2 ppm TDZ (N1T2), which gave the highest number of shoots. Higher concentrations of cytokinins can stimulate shoot growth.

Consequences of NAA, BA and GA3 treatment in early fruit development phase on postharvest properties of apricot cv. NS4

The effects of plant growth regulators (PGRs) including representative compounds from the group of cytokinins, auxins and gibberellins, on fruit quality and postharvest properties during 15 days of cold storage and 3 days of shelf life were compared. Apricots, cv. NS4, were treated with 1-naphthaleneacetic acid (NAA; 10 and 20 mg L–1), 6-benzyladenine (BA; 50 and 100 mg L–1) and gibberellin (GA3; 200 mg L–1) 14 and 21 days after full bloom. Application of PGRs resulted in increase of ash, total soluble solids and decrease of water content in fruit, while the color of fruits was characterized with lighter skin and with more intensive color changes during postharvest period. BA decreased the content of majority of cations, while higher dosage of this compound resulted in the lowest fruit firmness. Application of NAA and GA3 increased of Ca and Mg content and resulted in the most expressed water loss. Titrable acidity and pH were not affected by any applied treatments.

Identification and expression analysis of the grape pentatricopeptide repeat (PPR) gene family in abiotic stress.

The pentatricopeptide repeat (PPR) is one of the largest gene family in plants, and play important role in regulating plant growth, development and abiotic stress response. However, PPR genes have been poorly studied in grapes. In this study, based on the grape genome database, bioinformatics methods and quantitative real-time PCR (qRT-PCR) were used to identify the VvPPR family and the response to abiotic stress. A total of 181 PPR genes were identified in grape and divided into two subfamilies. Subcellular localization predicted that this gene family mainly functions in chloroplasts, nucleus, and mitochondria. Protein-protein interaction prediction indicated that there may be interaction between VvPPR44,53 and VvPPR44. The promoter region of VvPPR gene family contained various cis-acting elements, which were related to light and hormone. Expression pattern analysis showed that the VvPPR gene family was highly expressed in grape leaves, buds and carpel tissues. qRT-PCR results showed that the expression of VvPPR genes in roots was higher than stems and leaves under NAA, SA, ABA, MeJA and GA3 treatments. VvPPR8 was significantly up-regulated after GA3 and MeJA treatment for 24h, VvPPR53 was significantly up-regulated after SA, NAA, ABA and MeJA treatment. In addition, In grape leaves, VvPPR53 was up-regulated under PEG, Nacl and 4℃ treatments. These data indicate that VvPPR gene family members are responsive to hormones and abiotic stresses, and that there are some differences in the degree of response and expression in different grape tissues. This study provides a certain theoretical basis for grape resistance breeding.

Transcriptomic analysis and physiological characteristics of exogenous naphthylacetic acid application to regulate the healing process of oriental melon grafted onto squash.

The plant graft healing process is an intricate development influenced by numerous endogenous and environmental factors. This process involves the histological changes, physiological and biochemical reactions, signal transduction, and hormone exchanges in the grafting junction. Studies have shown that applying exogenous plant growth regulators can effectively promote the graft healing process and improve the quality of grafted plantlets. However, the physiological and molecular mechanism of graft healing formation remains unclear. In our present study, transcriptome changes in the melon and cucurbita genomes were analyzed between control and NAA treatment, and we provided the first view of complex networks to regulate graft healing under exogenous NAA application. The results showed that the exogenous NAA application could accelerate the graft healing process of oriental melon scion grafted onto squash rootstock through histological observation, increase the SOD, POD, PAL, and PPO activities during graft union development and enhance the contents of IAA, GA3, and ZR except for the IL stage. The DEGs were identified in the plant hormone signal-transduction, phenylpropanoid biosynthesis, and phenylalanine metabolism through transcriptome analysis of CK vs. NAA at the IL, CA, and VB stage by KEGG pathway enrichment analysis. Moreover, the exogenous NAA application significantly promoted the expression of genes involved in the hormone signal-transduction pathway, ROS scavenging system, and vascular bundle formation.

Effects of α-Naphthylacetic Acid on Cadmium Stress and Related Factors of Tomato by Regulation of Gene Expression

Cadmium (Cd) is absorbed and accumulated by crops, and it adversely affects plant growth and development. To explore the effect of exogenous auxin on Cd stress, we applied different concentrations of α-naphthaleneacetic acid (NAA) and the auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) to tomato plants exposed to Cd stress in a hydroponic system. NAA and TIBA at different concentrations were used under Cd stress. Plant growth, root morphology, and auxin distribution were observed. Lipid peroxidation and antioxidant enzyme activities in leaves, cadmiumcontent, and migration coefficient of plants were determined. Transcriptome sequencing and qRT-PCR were used to analyze the differentially expressed genes. Results showed that auxin was concentrated in the leaf veins, stem base, and roots in P5::GUS “Chico III” transgenic tomato, indicating NAA polar transport to the roots and promotion of root growth under Cd stress. Cd was absorbed by the roots and transported to the shoots. It then inhibited plant growth and promoted antioxidant enzyme activities, O2− production, H2O2 accumulation, and membrane lipid peroxidation. Treatment with 0.5 μM NAA improved antioxidant enzyme activities, reduced reactive oxygen, maintained membrane permeability, and decreased malondialdehyde and proline contents. Transcriptome analysis revealed that NAA activated a large number of genes in the roots: 1998 genes were differentially expressed in response to Cd or NAA treatment, and 1736 genes were specifically expressed in response to NAA treatment under Cd stress. Among the differentially expressed genes, tomato metallocarboxypeptidase inhibitor TCMP-2 (2A11) and Solanum lycopersicum heavy metal-associated isoprenylated plant protein (HIPP) 7-like (LOC101264884), which are closely related to plant response to heavy metal stress, may be the key sites of NAA. In conclusion, the NAA-mediated response to Cd stress was closely associated with “defense response” genes in shoots and “oxidoreductase activity, oxidizing metal ions” and “response to auxin” genes in roots.

Genome-Wide Identification and Analysis of the Growth-Regulating Factor Family in Zanthoxylum armatum DC and Functional Analysis of ZaGRF6 in Leaf Size and Longevity Regulation.

Growth-regulating factors (GRFs) are plant-specific transcription factors that play an important role in plant growth and development. In this study, fifteen GRF gene members containing QLQ and WRC domains were identified in Zanthoxylum armatum. Phylogenetic and collinearity analysis showed that ZaGRFs were closely related to CsGRFs and AtGRFs, and distantly related to OsGRFs. There are a large number of cis-acting elements related to hormone response and stress induction in the GRF gene promoter region of Z. armatum. Tissue-specific expression analysis showed that except for ZaGRF7, all the ZaGRFs were highly expressed in young parts with active growth and development, including terminal buds, seeds, and young flowers, suggesting their key roles in Z. armatum growth and development. Eight ZaGRFs were selected to investigate the transcriptional response to auxin, gibberellin and drought treatments. A total of six ZaGRFs in the NAA treatment, four ZaGRFs in the GA3 treatment, and six ZaGRFs in the PEG treatment were induced and significantly up-regulated. Overexpression of ZaGRF6 increased branching and chlorophyll content and delayed senescence of transgenic Nicotiana benthamiana. ZaGRF6 increased the expression of CRF2 and suppressed the expression of ARR4 and CKX1, indicating that ZaGRF6 is involved in cytokinin metabolism and signal transduction. These research results lay a foundation for further analysis of the GRF gene function of Z. armatum and provide candidate genes for growth, development, and stress resistance breeding of Z. armatum.

Mutation of OsPIN1b by CRISPR/Cas9 Reveals a Role for Auxin Transport in Modulating Rice Architecture and Root Gravitropism.

The distribution and content of auxin within plant tissues affect a variety of important growth and developmental processes. Polar auxin transport (PAT), mainly mediated by auxin influx and efflux transporters, plays a vital role in determining auxin maxima and gradients in plants. The auxin efflux carrier PIN-FORMED (PIN) family is one of the major protein families involved in PAT. Rice (Oryza sativa L.) genome possesses 12 OsPIN genes. However, the detailed functions of OsPIN genes involved in regulating the rice architecture and gravity response are less well understood. In the present study, OsPIN1b was disrupted by CRISPR/Cas9 technology, and its roles in modulating rice architecture and root gravitropism were investigated. Tissue-specific analysis showed that OsPIN1b was mainly expressed in roots, stems and sheaths at the seedling stage, and the transcript abundance was progressively decreased during the seedling stages. Expression of OsPIN1b could be quickly and greatly induced by NAA, indicating that OsPIN1b played a vital role in PAT. IAA homeostasis was disturbed in ospin1b mutants, as evidenced by the changed sensitivity of shoot and root to NAA and NPA treatment, respectively. Mutation of OsPIN1b resulted in pleiotropic phenotypes, including decreased growth of shoots and primary roots, reduced adventitious root number in rice seedlings, as well as shorter and narrower leaves, increased leaf angle, more tiller number and decreased plant height and panicle length at the late developmental stage. Moreover, ospin1b mutants displayed a curly root phenotype cultured with tap water regardless of lighting conditions, while nutrient solution culture could partially rescue the curly root phenotype in light and almost completely abolish this phenotype in darkness, indicating the involvement of the integration of light and nutrient signals in root gravitropism regulation. Additionally, amyloplast sedimentation was impaired in the peripheral tiers of the ospin1b root cap columella cell, while it was not the main contributor to the abnormal root gravitropism. These data suggest that OsPIN1b not only plays a vital role in regulating rice architecture but also functions in regulating root gravitropism by the integration of light and nutrient signals.

Impact of in vitro hormone treatments on the bibenzyl production of Radula complanata

Bibenzyls are a specialized metabolite class found throughout the plant kingdom. One of the most prolific producers of bibenzyls are liverworts, specifically plants of the Radula genera. These plants possess an incredible diversity of bibenzyls, prenylated bibenzyls, and a few (bis)bibenzyls, several of which have medicinal properties, including perrottetinene, an analog of tetrahydrocannabinol from cannabis. To provide insight into the bibenzyls’ biosynthesis in planta, exogenous phytohormones were applied to in vitro grown Radula complanata and bibenzyl metabolite production was monitored with targeted and untargeted metabolomics. The targeted metabolomic analysis of six prenylated bibenzyls revealed that production of these metabolites was largely reduced when plants were treated with abscisic acid (AA), salicylic acid (SA), 1-naphthaleneacetic acid (NAA), or 6-benzylaminopurine (BAP). The reduction of these metabolites in the BAP and NAA treatment suggests that prenylated bibenzyl production is negatively correlated with vegetative plant growth. The reduction of bibenzyls at low AA and SA concentrations and mild increase at higher AA and SA concentrations suggest that their production is regulated by these stress hormones. In addition, six other bibenzyl metabolites were tentatively identified from the untargeted analysis. These results provide insight into the influence of phytohormones on the bioactive bibenzyl content of R. complanata.

Molecular dissection of genes and promoters involved in glycyrrhizin biosynthesis revealed phytohormone induced modulation in Glycyrrhiza glabra L

The study reports cloning and characterization of complete biosynthetic gene cluster committed to glycyrrhizin biosynthesis along with their corresponding promoter regions from Glycyrrhiza glabra. The identified genes namely, β-amyrin synthase, β-amyrin-11-oxidase, 11-oxo-beta-amyrin 30-oxidase and UDP-dependent glucosyltransferase, were hetrologously expressed in Nicotiana benthamiana for functional validation. The phyto-hormone, naphthalene acetic acid was shown to prompt maximum up regulation (1.3–14.0 folds) of all the genes, followed by gibberellic acid (0.001–10.0 folds) and abscisic acid (0.2–7.7 folds) treatments. The promoter-GUS fusion constructs infiltrated leaves of the identified genes exhibited enhanced promoter activity of β-amyrin synthase (3.9 & 3.0 folds) and 11-oxo-beta-amyrin 30-oxidase (3.6 & 3.2 folds) under the GA3 and NAA treatments, respectively as compared to their respective untreated controls. The transcriptional control of the three phytohormones studied could be correlated to the cis-responsive elements present in the upstream regions of the individual genes. The study provided an insight into the intricate interaction between hormone-responsive motifs with the corresponding co-expression of the glycyrrhizin biosynthetic pathway genes. The study will help in understanding the phytohormones-mediated regulation of glycyrrhizin biosynthesis and its modulation in the plant.

The Effect of Auxin and Cytokinin on Black Orchid Hybrid (Coelogyne pandurata Lindley) in Vitro

The Orchid is an ornamental plant with high economic value due to the emergence of unique varieties. These varieties are produced from conventional breeding methods of crossing and selection. Meanwhile, the propagation of orchids through in vivo hatcheries is constrained because the seeds are too small to contain the endosperm. Tissue culture is an alternative for the propagation of orchids Efforts to propagate orchids through tissue culture is carried out by adding Growth Regulatory Substances such as auxins groups, namely NAA, IBA, IAA, and cytokinin groups, namely BA, BAP, kinetin, and TDZ to MS media, to enable the plants to take up adequate nutrients for growth. Therefore, this study aims to determine the effect of various concentrations of NAA and BA on the best ½ MS media for the growth of orchid subcultures. A completely randomized design pattern (CRD) of 2 factors with 12 treatment combinations and four replications were used, totaling 48 experimental units. The results showed that the addition of 1ppm NAA had the highest number of roots and length, while the addition of BA at 3ppm had the highest height, and the combination of 1ppm NAA and BA 3ppm treatment produced the highest number of leaves (42 sheets) and shoots. Based on the results, the addition of NAA above 3ppm followed by BA at 6ppm can produce more leaves and shoots, while NAA above 3ppm can produce higher plant height.

Root Development Characteristics of Three Syringa Species as Affected by IBA and NAA Treatments

Root Development Characteristics of Three Syringa Species as Affected by IBA and NAA Treatments

Rooting effects of NAA treatment on cuttings of persimmon dwarfing rootstock ‘Hourakudai’ and growing conditions for grafted scions

Rooting effects of NAA treatment on cuttings of persimmon dwarfing rootstock ‘Hourakudai’ and growing conditions for grafted scions

Impact of Agronomical Approaches on Growth, Yield and Economics of Bell Pepper (Capsicum annuum L.) var. Solan Bharpur under Mid-hills of Himachal Pradesh

Background: Capsicum annuum L., popularly known as bell pepper, sweet pepper and shimla mirch, is a vegetable crop in the Solanaceae family. Because of its various nutritional benefits, capsicum is ranked one of the healthiest vegetables; therefore desire for this is expanding every day. Through its importance and market requirement in consideration, a study was conducted to assess the impact of planting methods, mulches and NAA treatment on bell pepper growth, yield and economics. Methods: The study was performed at Experimental Farm of the Department of Vegetable Science, Dr Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan (HP) during Kharif seasons of year 2017-18 and 2018-19 (two years). The experiment was laid out in arandomized block design with three replications comprising twelve treatments. Result: Study revealed that T3 yielded maximum (384.69 q/ha) as well as recorded maximum values of gross return (Rs. 577,035.00/-), net return Rs. 3,52,416.93/- and comparatively less B:C ratio (1:57). Meanwhile, T1 recorded 77.80% control in weed population and have maximum (64.12%) efficiency to control emerging weeds as compared to T12.

The Pivotal Role of Phenological Stages Enhanced by Plant Origin Preparations in the Process of Rhizogenesis of Rosa ‘Hurdal’ Stem Cuttings

Some biostimulants, including plant origin preparations, act similarly to plant growth regulators. Moreover, the supplementation of known and unknown rooting cofactors can stimulate rhizogenesis in cuttings. The aim of this research was to assess the response of difficult-to-root and long-rooting stem cuttings of the once-blooming old variety Rosa ‘Hurdal’ to preparations of plant origin. The hypothesis was that the plant origin preparations could enhance rooting processes by inhibiting chlorophyll a/b degradation in leaves and postponing leaf senescence, simultaneously increasing the quality of cuttings. The one-bud stem cuttings were made in four phenological stages: (H1) flower buds closed, (H2) open flowers, (H3) just after petal fall, and (H4) 7–14 days after petal shedding. They were treated with either standard commercial powder preparations containing 0.4% indole-3-butyric acid (IBA) or 0.2% 1-naphthalene acetic acid (NAA) as well as with commercial plant origin preparations that this work will henceforth refer to as: Algae Extract, Organic Preparation, and Plant Extract. The cuttings were evaluated after 12 weeks of rooting them in two substrates: peat–perlite and peat–sand (v:v; 1:1). Mean root percentages for both substrates were noted after preparation from stage H1 (74.5%), H2 (59.5%), H3 (50.8%) shoots. The H4 cuttings did not root at all and were not considered further. The means for all phenology stages together were the highest by the use of 0.6% Algae Extract, 0.012% and 0.02% Organic Preparation, and 0.2% and 0.4% Plant Extract. The lowest means were reported for the control cuttings as well as NAA and IBA treatment. Plant origin preparations encouraged growth parameters but did not unequivocally inhibit the decrease of chlorophyll content in the cuttings’ leaves. The percentage of cuttings that rooted in both rooting substrates was determined by the quality of the cuttings as well as the chlorophyll a/b and soluble protein content in the leaves.

RESPON KALUS KENCUR (Kaempferia galanga L.) TERHADAP CEKAMAN KEKERINGAN DENGAN PERLAKUAN POLYETHYLENE GLYCOL 6000 DAN NAPTHANELE ACETIC ACID

Kencur (Kaempferia galanga L.) is a plant that has a high enough rhizome selling value. Increased production can be done by expanding the land. However, cultivated land in Indonesia is generally dominated by dry land with limited water availability. The research objective was to obtain galanga callus that were tolerant of drought in vitro using the PEG 6000 selective agent. Randomized block design (RBD) 2 factors were repeated 3 times. PEG 6000 concentrations were 0%, 5%, 10%, 15%, 20% and NAA concentrations were 1mg/l, 1.5mg/l, 2mg/l. The parameters observed were callus morphology (texture and color), wet weight, dry weight, percentage of fresh callus, number of roots, proline content, and live callus percentage. The results showed compact textures that were green, white, and brown. Wet weight, dry weight, percentage of fresh callus, number of roots of PEG 6000 treatment resulted in a decreasing value while the proline content increased with the increase in PEG 6000 concentration. The NAA treatment at the concentration of 1mg/l produced the most roots, while the percentage value of fresh callus was inversely proportional to the value of the proline content. The lower the PEG 6000 and NAA concentrations resulted in more roots. The higher the PEG 6000 concentration and the lower the NAA concentration resulted in high the proline content. PEG 6000 20% still produced 61% living callus.

Increasing off-season snake fruit (Salacca zalacca) yield by preventing fruit set failure with different exogenous auxin spray

Snake fruit blooms every three months, but only one to two of the flowering seasons result in fruit production. Failure of fruit set causes the fruit harvest seasonally. Therefore, the aim of this research was to increase off-season production by preventing the failure of fruit set with various exogenous auxin spray. The research was conducted in the snake fruit orchard at Bebandem Sub-District, Karangasem Regency, Bali Province, Indonesia, from February to November 2019. The experiment was designed as a nested factorial with a randomized block design. The treatment consisted of three types of auxin with a specific concentration for each, IAA at 0, 25, 50 and 75 ppm, IBA at 0, 50, 100 and 150 ppm, and NAA at 0, 50, 100 and 150 ppm. The IAA, IBA, and NAA were sprayed on the flowers and leaves 3 times in March, April, and May. The results showed the highest percentage of fruit set, fruit weight per tree, and weight per fruit obtained with IAA treatment were 59.80 %, 2,612.91 g, and 91.06 g, respectively. These results were not statistically different to those of the IBA and NAA. Furthermore, the IAA concentration of 25, 50, and 75 ppm produced a significantly higher percentage of fruit set compared with the control. The increased fruit set in the IAA, IBA and NAA treatments resulted in better yield than the control. The novelty of this result is that spraying snake fruit with IAA, IBA and NAA can prevent the failure of the fruit set. Therefore, IAA, IBA, and NAA are recommended to be applied to increase off-season fruit production of snake fruit.

Efficacy of Different Concentrations of NAA on Selected Ornamental Woody Shrubs Cuttings

Ornamental woody shrubs are used in landscape design worldwide. Their propagation can be made generatively and vegetatively. Vegetative propagation methods are mostly used by nurseries, as such methods are quick and the newly propagated plants inherit the genetics of the mother plant. However, rooting in some woody plants is slow and, unfortunately, sometimes produces only a small number of rooted cuttings. In this study, shoot cuttings from six selected ornamental woody shrubs were subjected to different concentrations of rooting stimulators (0.5 (NAA5) and 0.8 (NAA8) % concentrations of 1-Naphthylacetic acid; cuttings without treatment were considered as control) and propagated in two different periods (spring and summer). Our results show that significant changes were obtained in the plants under the different treatments. Most of the plants showed a positive response to both treatments, expect for Cotinus coggygria ‘Royal Purple’, which, compared to control, registered decreases in all the tested parameters under NAA5 treatment. Ilex aquifolium was the species that showed increments in all the parameters when NAA treatments were applied. In conclusion, our research suggests that NAA increases rooting in ornamental woody shrubs, although in some cases rooting could be a species-dependent process.