Biochemical changes in barberries during adventitious root formation: the role of indole-3-butyric acid and hydrogen peroxide

Peroxidase, polyphenol oxidase (PPO), phenolic compounds and total sugars (TS) were investigated during root formation in cuttings of Berberis vulgaris var. asperma (BVA) and Berberis thunbergii var. atropurpurea (BTA) treated with indole-3-butyric acid (IBA) and IBA+H2O2. Rooting was observed on BTA cuttings but not on BVA cuttings. The BTA cuttings treated with IBA and IBA+H2O2 showed higher rooting percentages, number of roots, and root length over the control. Those treated with IBA+H2O2 recorded the lowest peroxidase activity after planting. BTA cuttings treated with IBA+H2O2 showed the highest peroxidase activity at 50 d after planting; BVA cuttings under different treatments showed no significant difference for peroxidase activity at planting time or up to 80 d after planting. PPO activity for the BTA cuttings in the control treatment was lower than for other treatments during root formation. The cuttings in the IBA and IBA+H2O2 treatments showed increased PPO activity from 0 to 50 d after planting and a slight decrease in PPO activity from 60 to 80 d after planting. PPO activity for the BVA cuttings was significantly lower than for BTA during root formation. The BTA cuttings treated with IBA and IBA+H2O2 showed the highest phenolic compound content during root formation. The BVA cuttings displayed higher TS than BTA during the initial stage of root formation. A comparison of the anatomical structure of easy-to-root and difficult-to-root cuttings indicated that physical inhibitors did not affect the rooting capacity of BVA

Carnation etched ring virus elimination through shoot tip culture

Carnation etched ring virus (CERV) is the second most destructive virus which infects carnation and the only DNA virus among infecting viruses of carnation. In symptomatic leaves of carnation consist of mottling, necrotic and chlorotic flecks or blotches. Virus was detected by DAS-ELISA and PCR. Treatments consisted of different sizes of meristem and MS medium supplemented with different plant growth regulators (PGRS) (0.5 mg/l benzyl adenine (BA), 0.5 mg/l gibberellic acid (GA3) and medium without PGRS.). The plantlets were analysed by PCR in order to evaluate virus eradication. Results of PCR in vitro culture revealed that explant size and type of PGRS had a significant effect on elimination of CERV and the highest amount of it (100%) was observed on medium containing BA in meristem size of 0.4, 0.7 mm and the lowest amount of it (26%) was occurred on medium supplemented with GA3 in meristem size of 1mm. So far, there is no reporting about influence of PGRS on elimination of viruses

Effect of Scale Position and Medium Type on Bulblet Production of Hippeastrum (Hippeastrum × johnsonii) with Twin Scaling Method

Introduction: Amaryllis is grown as pot outdoor plant and cut flower. Generally, this ornamental plant propagates by seed, suckers and scale cutting. Propagating by seed is not commercial and often used to produce new varieties. On the other hand, number of bulblets per mother bulb is very low under normal condition. Besides each bulb produces only 2 or 3 bulblets in a growing season and they become mature and produce flower stalk after 2 to 3 years. In some cases bulbs have no capacity to produce bulblet. Therefore, one of the strategies for shortening the growth period of the plant is to improve the traditional methods of plant propagations. Materials and Methods: This study was done as a factorial experiment in a completely randomized design with 7 replications to evaluate the effects of medium and position of twin scales in mother bulbs on propagation of bulblets, in order to increase the rate of propagation of this ornamental plant. To measure wet and dry weight of explants, 3 replicates were used. For propagation, bulbs were cut radially into 12 equal pieces, so that each pieces were contained a part of the basal plate. To evaluate the effects of position of twin scales in mother bulbs, pieces were divided as twin scales and classified in 5 groups, so that the outermost twin scales was grouped in class 1 and the innermost twin scales was grouped in class 5. After that, the scale cuttings were dipped in 0.1 % carbendazim solution for 25 minutes and then surface water were dried using sterilized tissue paper. Media that used in this study were sand, perlite, vermiculite, Peat moss and cocopeat. For removing possible contamination from the media, all media were autoclaved for 30 minutes at 121 °C. Then twin scales cuttings were cultured in vented transparent plastic containers that filled with different media and were kept in a growth chamber at 25 °C and 16 hours lighting.Number of produced bulblet, bulblet diameter, root number, root length, fresh and dry weight of plants and browning rate of scales were recorded at the end of the experiment. Results and Discussion: The results showed that medium and twin scale position in the mother bulb had a significant effect on the quality produced bulblet. The highest fresh weight of bulblet (1.58 g), bulblet dry weight (0.21 g) and the maximum diameter of the produced bulblet (1.5 cm) were obtained in the outermost twin scales and peat moss medium. Analysis of variance showed that the effect of culture medium on the number and length of produced leaf was significant (

Biochemical changes in barberries during adventitious root formation: the role of indole-3-butyric acid and hydrogen peroxide

Peroxidase, polyphenol oxidase (PPO), phenolic compounds and total sugars (TS) were investigated during root formation in cuttings of Berberis vulgaris var. asperma (BVA) and Berberis thunbergii var. atropurpurea (BTA) treated with indole-3-butyric acid (IBA) and IBA + H2O2. Rooting was observed on BTA cuttings but not on BVA cuttings. The BTA cuttings treated with IBA and IBA + H2O2 showed higher rooting percentages, number of roots, and root length over the control. Those treated with IBA + H2O2 recorded the lowest peroxidase activity after planting. BTA cuttings treated with IBA + H2O2 showed the highest peroxidase activity at 50 d after planting; BVA cuttings under different treatments showed no significant difference for peroxidase activity at planting time or up to 80 d after planting. PPO activity for the BTA cuttings in the control treatment was lower than for other treatments during root formation. The cuttings in the IBA and IBA+H2O2 treatments showed increased PPO activity from 0 to 50 d after planting and a slight decrease in PPO activity from 60 to 80 d after planting. PPO activity for the BVA cuttings was significantly lower than for BTA during root formation. The BTA cuttings treated with IBA and IBA + H2O2 showed the highest phenolic compound content during root formation. The BVA cuttings displayed higher TS than BTA during the initial stage of root formation. A comparison of the anatomical structure of easy-to-root and difficult-to-root cuttings indicated that physical inhibitors did not affect the rooting capacity of BV

Effect of different Genotypes, Cytokinins and Auxins on In vitro Capitulum Regeneration of Gerbera (Gerbera jamesonii)

Introduction: Gerbera is one of the most important ornamental plants in the world. The importance of Gerbera is due to its beauty, diversity and economically aspects. Traditional propagation methods such as crown division and cutting methods are not suitable for obtaining disease free plants and rapid multiplication. These methods also do not have the capacity to fulfill global demands. Therefore, obtaining efficient protocol for micropropagation of this ornamental plant is necessary. Materials and Methods: In this study the effect of various factors on in vitro regeneration, proliferation, rooting and acclimation of gerbera capitulum explants were analyzed in four separate experiments. Capitulum explants were first washed with running tap water for 30 min then surface sterilized by dipping in 1.5% sodium hypochlorite solution for 15 min and rinsed with sterile distilled water, followed by immersing in 0.1 % mercuric chloride solution for 10 min. To remove mercuric chloride residue, capitulum was rinsed with sterile distilled water. Subsequent washing was done with sterile distilled water for three times. Sterilization steps were done under laminar air flow hood. For regeneration, eight genotypes of gerbera capitulum explants (Famous, Sunway, Red Pearl, Pink Snow, Popov, Balance, Dune, Eagle)were cultured on solid MS medium containing several cytokynins, BA, TDZ, 2IP or KIN (4 mg/l) in combination with IAA (0.2 mg/l). In proliferation stage, the effect of different concentrations of BA was evaluated on proliferation rate of Sunway regenerated explants. In the rooting stage, Sunway genotype plantlets were cultured on ½ MS medium containing NAA, IBA or IAA (1 mg/l) or ½ MS medium without any hormones. The pH of the medium was adjusted to 5.7-5.8 prior to autoclaving (15 min at 121 oC and 1.5 kg.cm-2 pressure). The cultures were incubated in a growth chamber at 25±2 oC with a 16-h photoperiod (2500-3000 Lux) provided by cool-white fluorescent lamps. For acclimation of rooted plantlets, different substrates used as follow: 1- perlite, 2- perlite: Cocopeat, 3- Cocopeat: peat moss, 4- Cocopeat: peat moss; treated with fungicide. After 30 days, the response of explants was evaluated for each experiment. Data preparation was done in the Excel program and data analysis was done using JMP-8 software. Mean comparison of the treatments was done by Tukey test and finally the charts were drawn using the Excel program. Results and Discussion:The results of regeneration stage showed that application of MS media containing kinetin or 2IP did not make an appropriate response to capitulum explants and no regeneration was observed in this condition. The medium containing 4 mg/l BA and 0.2 mg/l IAA indicated the highest percentage of regeneration in all genotypes. The highest regeneration was observed in Sunway genotype with an average of 21.96%. On the other hand no regeneration was observed in Eagle genotype. In terms of the number of regenerated plantlet, the highest number (61.2) was attributed to the Sunway genotype while no plantlet was recorded for Eagle genotype. No significant differences were also observed between Pink Snow and Dune genotypes. For the proliferation stage, only Sunway genotype was utilized due to its vigorous growth in comparison to other genotypes. In this stage, the highest (6 regenerated plantlets) and the lowest (1 regenerated plantlet) regeneration rate were observed in MS medium containing 2 mg/l BA and hormone-free medium, respectively. Hormone-free ½ MS medium and ½ MS medium containing 1 mg/l IAA or IBA, indicated the highest rooting rate (100% rooting) while medium containing 1 mg/l NAA showed 55% rooting rate. It seems that the application of NAA in the medium composition had the lowestimpact on the rooting of regenerated plantlets. At the end of the experiment, the highest (90.42%) and the lowest (47.5%) acclimation rate was obtained in peat moss + cocopeat + fungicide medium and perlite medium, respectively. Conclusions: Generally, for shoot induction of gerbera through capitulum culture, application of MS medium containing 4 mg/l BA and 0.2 mg/l IAA is recommended. It is also concluded that for proliferation stage, the MS medium containing 2 mg/l BA showed the highest rate of regeneration. Using of Hormone-free ½ MS medium is economically affordable. Finally for acclimation of the plantlets, application of peat moss + cocopeat + fungicide medium is recommended