Highest Percentage Of Rooting Research Articles

In Vitro Propagation and Histochemical Analysis of Launaea sarmentosa (Willd.) Kuntze

Launaea sarmentosa (Willd.) Kuntze., an edible perennial herb, is critically considered an endangered species due to its habitat destruction. In vitro L. sarmentosa propagation was therefore conducted to preserve this plant. Two types of explants including leaf and stolon were applied to induce the multiple shoots by culturing on Murashige and Skoog (MS) medium supplemented with BA (0, 1, and 2 mg/L) and 2,4-D (0, 1, 2, and 4 mg/L). The optimal shoot induction medium for both explants was MS medium containing 2 mg/l BA (presented 100 % shoot induction). Roots were induced by various types and concentrations of auxins [1-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), and indole-3-butyric acid (IBA)]. The highest percentage of rooting (70.00 ± 11.05 %) was obtained from stolon-derived shoots on MS medium supplemented with 0.1 mg/l IAA. One-hundred percent survivability was presented after transforming plantlets into a mixture of soil, sand, and peat moss (1:1:1). Starch, protein, and lipid were accumulated in leaves detected by histochemical technique. The obtained information will be a useful tool for mass propagation of L. sarmentosa and to obtain basic knowledge for plant accumulating substances. HIGHLIGHTS This paper highlights 2 types of sarmentosa explant including leaves and stolons have great potential to produce multiple shoots after inoculation in MS medium adding BA. All regenerated plants get success for acclimatization and transplantation to the greenhouse. In vitro plantlets of L. sarmentosa leaves accumulated fat, protein and carbohydrate which might be related with precursor of medicinal properties GRAPHICAL ABSTRACT

Warming reduces the root density and wheat colonization by arbuscular mycorrhizal fungi in the Yaqui Valley, Mexico

Some studies on the impact of climate changes on wheat have been carried out, but few have explained the possible variations in root morphology and associated microbial diversity. The present study aimed to evaluate the effect of canopy temperature increases of 2°C in wheat during three experimental crop cycles on the initial and final root density and the presence of symbiotic association with arbuscular mycorrhizal fungi (AMF) under field conditions. The warming treatment resulted in the highest percentage of roots (51%) at a greater depth than the control. The warming caused a 38% decrease in the presence of AMF and a 20% decrease in the number of spores per kilogram of soil. The warming treatment generated stress intensities of 18 and 17% in the amount of spore per kilogram of soil and percentage of colonization, respectively.

Rapid In Vitro Propagation of Fig (Ficus carica L.) ‘Violette de Solliès’ Supported by Molecular and Microscopy Analyses

Ficus carica L. is a common fig that is an incredibly nutritional fruit, well-known for its medicinal and economic values. This study aims to establish an efficient protocol for the mass propagation of fig plantlets (Ficus carica L.) for the cultivar ‘Violette de Solliès’. Surface-sterilized shoot-tip explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of cytokinins (6-benzylaminopurine, BAP; thidiazuron, TDZ; kinetin, Kn; and zeatin, Zea). Induced shoots were rooted on Woody Plant Medium (WPM) with different concentrations of auxins (naphthalene-acetic acid, NAA; indole-3-acetic acid, IAA; and indole-3-butyric acid, IBA). Rooted explants were acclimatized in eight different soil substrates prior to cultivation in a commercial plot. The propagated plantlets were analyzed for genetic stability and clonal fidelity using RAPD and SCoT molecular markers, whereas scanning electron microscopy (SEM) was performed to observe the stomata morphology of post-acclimatized plants. MS media supplemented with 5.0 mg/L BAP was the optimal treatment for multiple shoot induction (15.20 ± 1.03 shoots), whereas the highest percentage of rooting (93.33%) was achieved in WPM supplemented with 3.0 mg/L IBA. Plantlets were successfully acclimatized in biochar soil with a survival rate of 100%. RAPD and SCoT analysis showed no polymorphism occurrences across six subculture cycles, whereas observations via SEM indicated normal stomata structures on the leaves of acclimatized plantlets. This study documents an efficient micropropagation protocol for Ficus carica cv. ‘Violette de Solliès’ for the production of uniformed and true-to-type plant stocks suitable for commercial propagation.

Pengaruh ekstrak bawang putih terhadap pertumbuhan setek batang pada berbagai jenis bugenvil (Bougainvillea spectabilis Willd)

This research aimed to study the effect of garlic extract on the growth of stem cuttings of several types of bougainvillea and used a factorial randomized block design (RAK) with two factors. First factor is garlic extract in 2 levels, (with or without garlic extract). Second factor 2 is the type of bougainvillea consisting of 5 varieties such as yellow flowers, dark purple flowers, white flowers, red flowers and orange flowers. The results showed that the interaction between onion extract and bougainvillea had no significant effect on all observed variables (sprouting time, number of shoots, shoot length, number of roots, root length, percentage of cuttings sprouted and percentage of rooted cuttings). Garlic extract had no significant effect on all observed variables. There was a tendency for cuttings given garlic extract to show a faster age of budding, more shoots, longer roots and more roots. The type of bougainvillea gave a very significant effect on all observed variables except the number of shoots. Red flowers show the earliest age to start sprouting (16.80 days), the longest shoots (26.03 cm) and the longest roots (9.43 cm). Orange flowers performed the highest number of shoots (4.79), the highest percentage of shoots (96.67%) and the highest percentage of roots (96.67). Yellow flowers showed the latest sprouting time (37.08 days), the shortest shoot length (2.51 cm), the shortest root length (1.56 cm), and the least number of roots (1.06). Dark purple flowers showed the lowest percentage of budding and root percentage (63.33%).

Effect of different concentrations of indole butyric acid, putrescine and hydrogen peroxide on stem cuttings of the rootstock GF677(Prunus amygdalus × Prunus persica) according to the cutting season

The rootstock GF677 is an interspecific hybrid with an important economic and horticultural value. In this research, the effect of indole butyric acid (IBA) in combination with putrescine (Put) and hydrogen peroxide (H2O2) on rooting of GF677 semi-hardwood stem cuttings in three cutting seasons (July, March and October) was investigated. Treatments as IBA (0, 1000, 2000 and 3000 mg L-1), Put (0, 800, 1600 and 3200 mg L-1) and H2O2 (1.5, 3 and 6% w/v) were included. The results showed that in July cuttings, the highest levels of callogenesis were observed in IBA treated cuttings in both concentrations of 1000 and 2000 mg L-1. The rooting was very low in July cuttings, while the highest percentage of rooting (14%) was observed in the combination of 2000 mg L-1 IBA+ 3% H2O2. In March, the cuttings treated by 1000 mg L-1 IBA+800 mg L-1 Put and 1000 mg L-1 IBA+1600 mg L-1 Put revealed the highest percentages of callus formation 83.31 and 83.33%, respectively. In these cuttings, the highest percentage of rooting (63.88%) was gained at 2000 mg L-1 IBA+3200 mg L-1 Put. The application of 1000 mg L-1 IBA+800 mg L-1 Put increased root fresh weight. In cuttings prepared in October, only 800 mg L-1 Put caused callus formation in more than 55% of the cuttings. The rooting of cuttings at this time was as low as the July cuttings, whereas the highest rooting percentage was observed in cuttings treated with IBA at a concentration of 1000 mg L-1. Overall, the experiment showed that the season of the cutting and the treatments with IBA+Put or H2O2 could improve rooting properties of the rootstock GF677.

Mini-cutting rooting and plantlet growth in Erythrina crista-galli L.

In this study, we evaluated the adventitious rooting competence of mini-cuttings and plantlet growth of two clones of swamp cork (Erythrina crista-galli L.). Experiments were carried out in a factorial of two clones to study the need of application of indolebutyric acid (IBA), substrate composition for mini-cutting rooting and plantlet growth, and rooting curves of the clones 15SM05 and 15SM08, in the completely randomized design. Mini-cuttings of swamp cork clones showed high rooting competence, with mean rooting percentage above 80% even without IBA application. Vermiculite and its combination with commercial substrate resulted in the highest percentage of rooting, and number and length of roots and shoots. The clones showed differences regarding their adventitious rooting competence and the increment in rooted mini-cuttings with time in a humidity chamber, being the clone 15SM05 the most suitable for plantlet production.

Evaluación de la propagación asexual por esquejes en Sesuvium verrucosum Raf. (Aizoaceae)

La sequía y la salinidad son condiciones de algunos suelos que limitan la producción agrícola a nivel mundial. Para combatir estos efectos, se ha hecho énfasis en una técnica llamada fitodesalinización, la cual consiste en el uso de especies halófitas con la capacidad para extraer cantidades importantes de sodio (Na+) del medio afectado. Sin embargo, ésta es una práctica agrícola que demanda una gran cantidad de material vegetal por hectárea, lo cual dificulta su implementación en los sistemas productivos con problemas de salinidad. El objetivo de este trabajo fue determinar la capacidad de enraizamiento de los esquejes de la especie halófita S. verrucosum y analizar los cambios de magnitud en sus parámetros biométricos, a partir de diferentes concentraciones en el tratamiento hormonal, en un periodo de 90 días. Para el desarrollo del experimento se utilizó un diseño experimental completamente al azar y se consideraron dos factores: las concentraciones del ácido indol butírico (AIB) (0, 800, 1 200, 1 600, 2 000 y 4 000 mg L-1) y la posición de los esquejes (basal-intermedia e intermedia-apical). Los resultados obtenidos demostraron diferencias significativas entre los diferentes tratamientos. Los esquejes de la porción intermedia-apical fueron los que obtuvieron el mayor porcentaje de enraizamiento, número de raíces, peso fresco y seco, tanto de la raíz como de la parte área de la planta, diámetro del tallo y altura de la planta, principalmente a una concentración de 2 000 mg L-1. A través de este método, es posible implementar la fitodesalinización de manera extensiva.

PROPAGACIÓN VEGETATIVA DE Pinus patula SCHIEDE ex SCHLTDL. et CHAM. EN DIFERENTES SUSTRATOS

Pinus patula Schiede ex Schldl. et Cham. es una especie endémica de México utilizada en plantaciones forestales comerciales en Sudamérica y Sudáfrica. La propagación masiva de materiales mejorados de esta especie, a través de estacas enraizadas, permite aumentar su productividad y homogeneizar sus productos. Se compararon cinco sustratos a base de aserrín fresco y corteza de pino en diferentes proporciones (1:9, 3:7, 5:5, 7:3 y 9:1 v:v) para evaluar el enraizamiento de estacas de esta especie forestal. Se utilizó un diseño experimental de bloques completos al azar con cuatro repeticiones; la unidad experimental estuvo conformada por 25 estacas. Se analizaron las principales características físicas y químicas de los sustratos tales como porosidad total, porosidad de aireación, retención de humedad, densidad aparente, pH, conductividad eléctrica y capacidad de intercambio catiónico al inicio y al final del experimento. Las variables evaluadas fueron la supervivencia, enraizamiento, presencia de callo, número y longitud de raíces primarias y presencia de raíces secundarias a las 20 semanas de establecido el experimento. El sustrato con la mayor proporción de aserrín (9:1) presentó el porcentaje de enraizamiento de las estacas más elevado (77 %), en comparación con el testigo (1:9), donde se obtuvo 42 %. Se observó alta correlación (0.97, 0.97, 0.90) del enraizado con el porcentaje de aserrín, densidad aparente y pH, respectivamente. La mezcla de aserrín y corteza de pino (9:1) presentó características físicas y químicas apropiadas para la formulación de sustratos útiles para propagar P. patula mediante el enraizado de estacas.

In vitro micropropagation and genetic fidelity studies using SCoT and ISSR primers in Annona reticulata L.: an important medicinal plant

An efficient and reproducible in vitro plant regeneration protocol has been developed for Annona reticulata L., a medicinally important plant of family Annonaceae. This is the first report of an efficient in vitro micropropagation and genetic fidelity evaluation of Annona reticulata using nodal segments as explants. Nodal explants were cultured on Murashige and Skoog (MS) medium augmented with various concentrations of cytokinins alone and in combination with auxins. MS medium supplemented with 2.5 mg/l 6-benzylaminopurine (BAP) and 0.3 mg/l indole-3-butyricacid (IBA) combination has proven the best for optimum regeneration response (87.4%) and a maximum number of multiple shoots (6.33 ± 0.37). Rhyzogenesis occurred on half-strength MS medium supplemented with 4 mg/l IBA, resulted in the highest percentage of rooting (73%) and a maximum number of roots (4.65 ± 0.23) along with maximum root length (1.76 ± 0.08 cm). The well developed regenerates were shifted to the mixture of soil, sand and organic manure (2:1:1) in small plastic cups and acclimatized successfully. Genetic fidelity of the discussed etiquette was validated using two types of DNA fingerprinting techniques i.e. start codon targeted (SCoT), and inter simple sequence repeat (ISSR) analyses. Among the ten SCoT (SC) and ISSR primers used, an excellent amplification with scorable DNA bands was produced by SC9 and ISSR4 primers. The results showed that the regenerated plantlets are monomorphic and true-to-type with mother plant. This study provides important information about selection of suitable regeneration medium to improve multiple shoot induction and rooting of Annona reticulata. It can be used for commercial cultivation and for further genetic redevelopment investigation studies, also applied for large scale propagation of elite genotypes.

Propagation of Three Cultivars of Rosa hybrida L. through Stenting Method

In the commercial production of roses, introducing a method to reduce the time of propagation with maximum success is crucial. This study was conducted to investigate the effect of different concentrations (0, 1500, 3000, 4500 mg/L) of Indole-3-butyric acid (IBA) on propagation of three cultivars of Rosa hybrid L. ('Dolce Vita', 'Samurai' and 'Utopia') by stenting (simultaneous cutting and grafting) method under greenhouse conditions. The cultivars were grafted onto Rosa hybrida L. 'Natal Briar' rootstock. The factorial experiment was performed in a completely randomized design with three replications. The stentings were cultured in coco peat and perlite medium at 1:2 ratio in a greenhouse under mist system. After 60 days, the percentage of grafting, rooting percentage, root number, longest root length and fresh and dry weights of roots and shoot traits (including leaf number, shoot number, and longest shoot length) were determined on the stentings. The highest rate of rooting in Dolce Vita cultivar was obtained at 1500 mg/L IBA and in Samurai and Utopia cultivars at 4500 mg/L IBA. Among the three cultivars of roses, highest percentage of rooting (93.75%), healing percentage (93.75%), root length (12.47 cm), fresh weight (0.84 g) and dry weight (0.07 g) of roots were observed in stentings treated with 4500 mg/L of IBA in Rosa hybrida L. cv. Samurai. Interaction between IBA concentrations and cultivars on chlorophyll (a, b and total) and carotenoid contents were significant in all the three cultivars of roses.

Cloning by cuttings in Nordmann fir, Abies nordmanniana: hormonal characteristics in relation crown position, rooting competence, and orthotropism as ramets

Conifer tree species belonging to Abies are notoriously difficult to propagate vegetatively due to aging of material, slow rooting, and persistent plagiotropism in rooted cuttings. We produced orthotropic shoots by reiteration from strongly pruned trees (5–6 years and 12–14 years, respectively), and harvested cuttings in summer. By HPLC–MS we analyzed the stem base of each cutting for initial hormonal status, and used state-of-the art techniques for a lengthy rooting procedure. Rooting efficiency and orthotropism of the resulting ramets were recorded. Hormonal content varied significantly among cuttings types with differing positional origins on the mother tree. High rooting percentages were obtained in all types; a low original position on the main stem gave slightly better rooting but orthotropism in the ramets was slightly less frequent. Striking differences were found in cytokinin profiles between cuttings from young and mature trees. This might explain a generally lower rooting success in the latter; neither auxin levels nor the auxin: active cytokinin ratio showed any correlation with rooting capacity. Cuttings from mature trees were also less likely to remain orthotropic after rooting. Cuttings that eventually developed into orthotropic ramets were characterized by low ABA, and high levels in a range of cytokinins. The study suggests that active: conjugated cytokinins may be related to the maturation process in trees and that cytokinin content may also relate to shoot dimorphism. These results contribute to a protocol for propagation of orthotropic ramets in a Massart model tree species with strong plagiotropism.

Management of Propagation Techniques of the Specie Croton lechleri Muell.Arg

With the aim of increasing the production of Croton lechleri Mull.Arg plants due to its attributes as a medicinal plant, the effect of different types of stakes and substrates as root promoters under intermittent nebulization conditions was evaluated. The work was conducted through a randomized complete block scheme adapting a factorial of 4 × 3, being the factors types of stakes (apical with leaves, apical without leaves, medium and basal) and substrates (sand, sand + Aserrin (1:1) and Aserrin (100%) at the rate of 10 stakes per repetition totaling 360 stakes throughout the experiment. The percentage of root (%), dead stakes (%), sprouted stakes (%), dead stake diameter was evaluated. (mm), shoot length (cm) and root length (cm) The Aserrin provided the highest number of dead stakes and the smallest number of shoots in the species, with apical stakes with leaves and the combination of sand + Aserrin as a substrate providing the highest percentage of roots formed, therefore these two factors influence the production of plants in the dragon blood species.

Effect of different growth regulators on propagation of Mussaenda (Mussaenda erythrophylla ‘Rosea’) in subtropical zone of West Bengal

An experiment was carried out to study the effect of different growth regulators on propagation of Mussaenda (Mussaenda erythrophylla ‘Rosea’) during rainy season in subtropical zone of West Bengal under naturally ventilated polyhouse. Significant differences among the treatments on root emergence and proliferation were noticed. All the growth regulators like IAA, IBA and NAA @1000, 2000, 3000 ppm significantly improved the rooting in cutting of Mussaenda over the control. Early rooting was observed in July month cuttings in all treatments than the June month cuttings. The highest percentage of rooting (80%) was observed in July month cuttings when treated with NAA @ 3000 ppm. The maximum number of roots (24.00/cutting) and root length (6.90 cm) was also recorded in the same treatment. Rooted cuttings were transferred to the earthen pots after 45 days of cutting, 98% cuttings survived and established, when cuttings were treated with NAA @ 3000 ppm in the month of July. But the most meaningful results for all the attributes were recorded with NAA @3000 ppm. This treatment was found most effective for rapid multiplication of Mussaenda through tip cuttings under subtropical zone of West Bengal.

Rooting behaviour of stem cuttings of Eclipta prostata L. with varying concentrations of different plant hormones

Eclipta prostata L. commonly known as Bhringaraj is one of the most valuable and important medicinal herb. The whole plants are used in medicinal and cosmetic industries. But still it is considered as a wild weed due to lack of propagation technique. Vegetative propagation plays an important role for its commercial cultivation. The experiment on “Rooting behavior of stem cuttings of Eclipta prostata L. with varying concentrations of different plant hormones” was laid out under CRD design with 13 treatments and 3 replications at demonstration unit of KVK Tirap, Deomali, Arunachal Pradesh. From this experiment it could be concluded that IBA treated cuttings irrespective of concentration was the best for rooting in Eclipta prostata cuttings under climatic condition of Tirap . The highest percentage of rooting, number of roots, survivability percentage and minimum days to rooting were recorded in IBA 400 ppm, IBA 300 ppm, IBA 100 ppm and IBA 400 ppm treated cuttings respectively.

Mycorrhization affects root distribution of Lotus corniculatus and Calamagrostis epigeios in a nutrient poor heterogeneous soil in a rhizotron experiment

Plant growth can be highly dependent on symbiotic partners, such as arbuscular mycorrhizal fungi (AMF) that improve the plant's nutrient uptake. However, less is known about whether AMF can beneficially influence spatial root distribution, especially in soils with patchy nutrient concentrations. This study was conducted to evaluate root distribution and plant response of Lotus corniculatus and Calamagrostis epigeios in a heterogeneous nutrient poor soil under different mycorrhizal conditions.Heterogeneous soil conditions of a reclamation site in the Lusation mining district, consisting of a nutrient poor sandy soil with embedded large silt-clay fragments, were used for this rhizotron experiment. Treatments were non-mycorrhizal and mycorrhizal L. corniculatus and C. epigeios in sterile soil and in sterile soil with a fungal free soil solution and mycorrhizal plants in a non-sterile soil. Mycorrhizal fungi were exogenous (Funneliformis mosseae and Rhizophagus irregularis) in sterile soil and indigenous mycorrhizal fungi in non-sterile soil. Plants were grown in rhizotrons, with clay-silt fragments in a sandy soil matrix. Treatment response variables were root density, root and shoot biomass, shoot tissue nutrient concentrations, and percentage of roots in clay-silt fragments relative to total root biomass, mycorrhizal colonization and intraradical fungal alkaline phosphatase (ALP) activity.Exogenous mycorrhizal L. corniculatus plants had higher root mass density in clay-silt fragments than indigenous mycorrhizal and non-mycorrhizal plants while C. epigeios had only higher root mass density in clay-silt fragments relative to sandy soil only in exogenous mycorrhizal plants in sterile soil with soil solution. Non-mycorrhizal C. epigeios shoot biomass in sterile soil did not significantly differ from that of exogenous mycorrhizal treatments. The greatest shoot biomass for both plant species, was with the highest percentage of roots in clay-silt fragments relative to the total root system. Exogenous mycorrhizal plants of both species had highest shoot phosphorus concentrations in sterile soil with soil solution. However, intraradical fungal ALP activity was highest in indigenous mycorrhizal plants. The results indicate that mycorrhizal conditions can have a strong influence on spatial root development. The consequences are that conditions, which promote root growth, lead to more roots in nutrient rich clay-silt fragments and thus enhance plant exploitation of heterogeneously distributed soil nutrients.

MICROPROPAGACI ́ON DEBuddleja cordataY EL CONTENIDO DEVERBASC ́OSIDO Y FENOLES TOTALES CON ACTIVIDAD ANTIOXIDANTE DELAS PL ́ANTULAS REGENERADAS

Buddleja cordata is a medicinal plant distributed in Mexican territory that is characterized for producing phenolic compounds possessing antioxidant activity. It was evaluated the type of morphogenetic responses induced by plant growth regulators. Furthermore, the content of verbascoside and total phenols was determined, as well as the antioxidant activity in regenerated plantlets. The greatest shoot proliferation (29.2 shoots per explant) was achieved in the stem-nodes that were grown in a half-strength Murashige and Skoog medium containing 4.44 M N6-benzyladenine. The greatest shoot heights of 4.3 and 4.7 cm (statistically not dierent) were obtained with gibberellic acid at 4.34 and 8.67 M, respectively. The highest percentage of rooting (89.4%) occurred with 2.45-M indole-3-butyric acid with 20.3 roots per shoot and an average root length of 4.4 cm. Of the rooted shoots, 91.7% were able to survive after 30 days of acclimatization. The verbascoside (1.0 mg g1) and total phenols (24.8 mg of gallic acid equivalents g1) content was related to antioxidant activity of the regenerated plantlets. The micropropagation of B. cordata might represent an alternative about massive production and depict the basis of the establishment of commercial crops and genetic studies.

Effect of MgCl2 and double concentration of Murashige and Skoog medium on in vitro plantlet and root cultures generation in halophytic grasswort Salicornia brachiata

An improved micropropagation protocol has been developed for halophytic grasswort Salicornia brachiata by using double concentration of Murashige and Skoog (Physiol Plant 15:473–497, 1962) medium (DMS) supplemented with plant growth regulators. Best shoot bud induction (90 %) from nodal explants was observed on DMS supplemented with 3.0 mg L−1 6-benzyl aminopurine (BAP) and 0.5 mg L−1 Zeatin with >3 shoot buds. Shoot proliferation and elongation was achieved on DMS supplemented with 1.0 mg L−1 thidiazuron (TDZ) and 1.0 mg L−1 α-naphthalene acetic acid (NAA) with multiple shoot buds after 30 days of culture. Best callus response (78 %) was observed when stem explants were cultured on DMS supplemented with 2.0 mg L−1 2, 4-dichlorophenoxyacetic acid and 0.01 mg L−1 BAP. Regeneration from the callus was achieved when callus was cultured on DMS supplemented with 0.5 mg L−1 TDZ. These shoot buds were elongated on shoot proliferation and elongation medium. Elongated shoots (5 cm) could be rooted on DMS supplemented with 0.5–1.5 mg L−1 NAA, 0.5–1.5 mg L−1 indole-3-acetic acid and 0.5–1.5 mg L−1 indole-3-butyric acid. DMS medium supplemented with 0.5 mg L−1 NAA found to be best for rooting and the addition of 20 g L−1 magnesium chloride (MgCl2) to the medium resulted in highest percentage of rooting and not with the addition of sodium chloride (NaCl). Rooted plants could be established in soil with 55 % survival. In another set of study on root culture generation, many roots initiated from explants cultured on DMS supplemented with 2.0 mg L−1 NAA. Addition of 10 g L−1 MgCl2 was highly beneficial in stimulating root initiation and proliferation as compared to NaCl.

Inducción del crecimiento en estacas de morera (Mo- rus alba), con ácido indol butírico (AIB).

The experiment wasconducted at the "Alfredo Volio Mata" Experiment Station ofthe University of Costa Rica. The asexual seed was extractedfrom an established plantation that was harvested during fouryears with pruning intervals of 56-112 days. The selectedbranches were divided into three cuttings, 40 cm long with atleast three buds in the basal, medial and apical parts of eachbranch. The highest percentage of rooting and sprouting in a35-day period was observed in the 112 day-old cuttings: 9%sprouts, 12% roots and 31% with both sprouts and roots. Theoptimum age of the branch to obtain maximum sprouting androoting was estimated at 117 days. The cuttings taken fromthe basal and medial portions of the branch had 10% moresprouts and roots than the cuttings taken from the apical part.There were noticeable differences between the application ornot of IBA (P≤0.01). Depending on the age of the cuttingand the part of the branch it was taken from, the use of IBAcaused an 11 to 15% increase in total sprouting.

Shoot Induction, Biochemical Changes During in vitro Rooting in Paeonia lactiflora Pall 'Hortensis'

Background: Peony is an ornamental as well as medicinal plant which is difficult to propagate in vitro . Its major problem during in vitro culture is leaching out of phenols in the medium. It causes hindrance in growth and development. Rooting is a complex process and main step for vegetative propagation. The main objective is to propagate this plant and produce multiple copies and understand rooting phenomenon which is usually complicated. Methods: The underground rhizomatous buds of Paeonia lactiflora Pall. ‘Hortensis’ were selected as the explants. In vitro micropropagation was carried out along with biochemical studies during rooting process. Results: Shoot induction, axillary shoot proliferation and rooting were established. The best initial medium for ‘hortensis’ was the half-strength Murashige and Skoog (MS) medium (double-strength Ca ) supplemented with 1 mg L N +2 1 6 benzyl-adenine (BA) and 0.5 mg L Gibberellic Acid (GA ). Shoot induction was 100% with 6.2 shoots per explant. 1 3 Rooting was also observed on the half-strength MS medium supplemented with 1.0 mg L Indole-3-butyric Acid 1 (IBA) and indole-3-acetic acid (IAA). The highest percentage of rooting (15%) was observed when in vitro shoots were dipped in the full-strength liquid MS medium supplemented with 10.0 mg L IBA without agar for five days and then 1 transferred to the quarter strength MS medium without any Plant Growth Regulator (PGR). Conclusion: The cultivar P. lactiflora hortensis is hard to root in vitro. The activities of peroxidase, indole acetic oxidase, polyphenolic oxidase and phenolic content have been estimated prior to and after rooting. These enzyme activities and phenolics have been reported to play a major role in rooting.

Improving an in vitro propagation protocol for Cestrum nocturnum L.

The present study was carried out to assess the micropropagation of <em>Cestrum </em>(<em>Cestrum nocturnum<strong> </strong></em>L.) by using single nodes and shoot tips excised from soft cuttings using MS salts, 30 g × l<sup>-1</sup> sucrose, 7 g × l<sup>-1</sup> agar, and different concentrations of plant growth regulators in culture medium.<strong> </strong>The results revealed that the use of mercuric chloride (0.05%, HgCl<sub>2</sub>) for 7 minutes was very effective in preventing contamination and gave the highest survival percentage (99%). The highest response (100%) was gained at initiation stage from lateral bud explants on MS medium supplemented with 1.5 mg × l<sup>-1</sup> of BA with most of NAA concentrations. However, in case of terminal buds, higher percentages of responses were resulted from the interaction of BA (1.5 mg × l<sup>-1</sup>) with 0.2 mg × l<sup>-1</sup> NAA. The lateral buds also produced more new shoots as well as a higher number of leaves and length of new shoots on the medium supplemented with 1.5 mg × l<sup>-1</sup> BA as compared with those from terminal buds. Significant differences were observed at multiplication stage between the lateral buds and terminal buds, since the lateral buds produced a higher number of new shoots and leaves as well as longer new shoots. At rooting stage, the treatment with 1 mg × l<sup>-1</sup> IBA gave the highest percentage of rooting (100%), the highest number of roots (13.2 root/explant), and the longest roots (8.44 cm), respectively, on half strength MS medium. Plantlets obtained were transferred to pots and acclimatized with 90% success.