Development Of Adventitious Shoots Research Articles

Simultaneous production of triploid and hexaploid plants by endosperm culture with colchicine treatment in diploid Haemanthus albiflos

Haemanthus albiflos (Amaryllidaceae) is a monocotyledonous plant with high ornamental value. To increase the ornamental value of this species, polyploidy breeding was programmed in this study by employing endosperm culture for producing triploid plants. Further, we tried to produce hexaploid plant by colchicine treatment to endosperm-derived callus. As an initial step, endosperm explants harvested 8 weeks after flowering were cultured on Murashige and Skoog (MS) medium containing 5 mg L−1 4-amino-3,5,6-trichloropicolinic acid (picloram) and 5 mg L−1 6-benzylaminopurine (BAP) for callus induction. Induced calli were maintained on the same medium. Somatic embryos and adventitious shoots were observed after transfer the callus segments onto 1/2MS medium without plant growth regulators (PGRs). Further development of somatic embryos and adventitious shoots were achieved by transferring the callus segments onto 0.5 mg L−1 1-naphthaleneacetic acid (NAA) and 1 mg L−1 BAP. Complete plantlets were established after placing the regenerated shoots and developing embryos on 1/2MS medium without PGRs. Flow cytometric analysis revealed that diploid, triploid, and tetraploid plantlets were involved in these regenerants. When the endosperm-derived callus segments were treated with 0.2% (w/v) colchicine for 24, 48, and 72 h, 4 hexaploid plants were regenerated through the same regeneration procedures as mentioned above. Ploidy levels of the representative diploid, triploid, and hexaploid plants were also confirmed by counting chromosome numbers. Availability of endosperm culture in combination with colchicine treatment was discussed as the means for producing polyploid plants. Triploid plants were regenerated from endosperm-derived callus via somatic embryogenesis and adventitious shoot formation in diploid Haemanthus albiflos. Hexaploid plants were induced by colchicine treatment to the endosperm-derived callus.

Fire as a novel technique to stimulate adventitious shoots in the laboratory

Fire-stimulated flowering and fire-stimulated resprouting are associated traits common in plants that evolved in fire-prone habitats, e.g., Vellozia pyrantha, an iconic plant that has economic potential and is endemic to a fully protected area. By combining a natural phenomenon that drives demography and in situ evolution, we tested if fire can be used as a novel technique for plant multiplication through vegetative bud activation in V. pyrantha. The basal parts of microplants cultivated for 60 days (5 to 6 cm tall) were exposed to a flame using a Bunsen burner for five periods controlled by a timer (2, 4, 6, 8, and 10 s) and compared to unburned plants (control). After 30 days, the number of new shoots was counted, and the length of the longest shoot produced per individual was measured. Adventitious shoot development started 7 days after the fire incidence. The number of shoots per individual and length of the longest shoot produced were significantly higher in the 6- to 10-s treatments. Fire was an efficient and cheap way to induce adventitious shoot formation. This new method could also be applied to other resprouter species from fire-prone environments in the world. By combining a natural phenomenon that drives evolution with the bud stimulus expected, we found fire as an efficient and cheap way to induce buds.

Endosperm culture: a facile and efficient biotechnological tool to generate passion fruit (Passiflora cincinnata Mast.) triploid plants

Triploid plants represent an important resource for the breeding of fruit and ornamental plants. Here, we report a facile and robust system for regenerating passion fruit triploid plants (Passiflora cincinnata Mast.) through in vitro endosperm culture. We describe the histological and biochemical aspects associated with the de novo shoot organogenesis. Endosperms were cultured on Murashige and Skoog medium supplemented with 1.5, 2.0, and 3.0 mg L−1 of 6-benzyladenine or thidiazuron, while a cytokinin-free medium was used as control. The highest percentage of organogenic calli (56%) was estimated at 1.7 mg L−1 6-benzyladenine, whereas the highest average number of shoots (24.85) per explant was estimated at 1.6 mg L−1 6-benzyladenine. Flow cytometry and chromosomal analysis confirmed that endosperm-derived plants were triploid, with a chromosome count of 27 (2n = 3x = 27) as well as a DNA amount similar to that of endosperm and 1.5 times greater than in diploid counterparts (2n = 2x = 18). The regeneration of adventitious shoots was evident 30 days after culture and occurred from the reprogramming of edge cells of the endosperm. During this process, lipids and proteins were quickly mobilized in the early stages of shoot organogenesis, whereas carbohydrates were synthesized throughout the development of adventitious shoots. This observation illustrates the mobilization dynamics of endosperm reserves during de novo shoot organogenesis in P. cincinnata. Adventitious shoots induced by reprogramming of the outer cell layers of the endosperm generate true-to-type triploid passion fruit plants.

ОСОБЕННОСТИ ПОЛУЧЕНИЯ И СОХРАНЕНИЯ CANNA × HYBRIDA HORT. EX BACKER В УСЛОВИЯХ IN VITRO

The aim of the study was to investigate means of morphogenesis and explant regeneration characteristics in in vitro culture and to develop biotechnological methods for micropropagation and conservation of promising garden varieties of Canna. The experiments were conducted in the plant biotechnology and virology laboratory of the Nikitsky Botanical Garden, National Centre of Science. For the induction of adventitious shoot development of explants, a Murashige and Skoog (MS) nutrient medium was used having 30 g / l of sucrose, 10 g / l of agar-agar with BAP and TDZ growth regulators. For the in vitro deposition, explants (vegetative buds and meristemoids) were placed on a modified MS medium having 60 g / l of sucrose and 0.2-0.4 g / l of CCС. The culture vessels with explants were transferred to cooling chambers with a low positive temperature (2-6 ° C) and an illumination of 0.1-0.5 klx. It was found that for active adventitious shoot formation during cultivation of Dar Vostoka and Suevia explant varieties, it is necessary to add 1.27 mg / l of TDZ to the MS nutrient medium, and 1.91 mg / l of TDZ for the Livadia variety. It is shown that for the deposition of meristemoids of Dar Vostoka, Livadia and Suevia varieties, the nutrient medium of ½ MS with 0.15-0.25 g / l of CCC is optimal; for adventitious shoots of the Suevia variety, the optimal nutrient was ½ MS with 0.2 g / l of CCC.

Effects of media and hormones on the adventitious shoot regeneration and development of Manchurian ash

Effects of media and hormones on the adventitious shoot regeneration and development of Manchurian ash

Transcriptomic Profiling Analysis of Arabidopsis thaliana Treated with Exogenous Myo-Inositol.

Myo-insositol (MI) is a crucial substance in the growth and developmental processes in plants. It is commonly added to the culture medium to promote adventitious shoot development. In our previous work, MI was found in influencing Agrobacterium-mediated transformation. In this report, a high-throughput RNA sequencing technique (RNA-Seq) was used to investigate differently expressed genes in one-month-old Arabidopsis seedling grown on MI free or MI supplemented culture medium. The results showed that 21,288 and 21,299 genes were detected with and without MI treatment, respectively. The detected genes included 184 new genes that were not annotated in the Arabidopsis thaliana reference genome. Additionally, 183 differentially expressed genes were identified (DEGs, FDR ≤0.05, log2 FC≥1), including 93 up-regulated genes and 90 down-regulated genes. The DEGs were involved in multiple pathways, such as cell wall biosynthesis, biotic and abiotic stress response, chromosome modification, and substrate transportation. Some significantly differently expressed genes provided us with valuable information for exploring the functions of exogenous MI. RNA-Seq results showed that exogenous MI could alter gene expression and signaling transduction in plant cells. These results provided a systematic understanding of the functions of exogenous MI in detail and provided a foundation for future studies.

In vitro propagation and acclimatization of genipapo accessions

ABSTRACT Genipapo is a species with an intermediate seed storage behavior, and its germination is slow and asynchronous; therefore the tissue culture is an alternative strategy for the propagation in large-scale. This study aimed to evaluate three genipapo accessions at different micropropagation stages (adventitious shoot induction, in vitro rooting and acclimatization). Genipapo nodal segments from the Sabinópolis (AS), Cruz das Almas (CZA) and Núcleo Bandeirante (NB) accessions were used and inoculated in culture media with 0 and 1.0 mg L-1 6-benzylaminopurine (BAP). Different indole-3-butyric acid (IBA) concentrations were tested for in vitro rooting. Subsequently, the effect of two substrates on the seedling development of three genipapo accessions was assessed. The molecular characterization of accessions was performed using 15 inter-simple sequence repeat (ISSR) primers, and genotype clustering was performed based on genetic dissimilarity using the Unweighted Pair-Group Method with Arithmetic Mean (UPGMA). Culture media supplementation with 1.0 mg L-1 BAP favors the development of adventitious shoots and promotes a higher callogenesis percentage, leaf number and feasibility at 90 days of in vitro culture. The immersion of the basal portion of shoots for 20 seconds in all IBA solutions induces the rhizogenesis in the genipapo accessions at 90 days of in vitro culture. The substrates consisting of washed sand + dried coconut shell powder, at a 1:1 ratio by volume, and Topstrato HT(r) may be recommended for genipapo acclimatization. The NB accession is genetically different from the CZA and AS populations and shows superiority for most of the variables analyzed.

Assessment of Direct Regeneration in Germany (Matricaria chamomilla L.) and Shirazi Chamomiles (Matricaria recutita L.)

Introduction: German (Matricaria chamomilla L.) and Shirazi (Matricaria recutita L.) chamomiles are the most important medicinal plants of the Astraceae family which are used in the pharmaceutical, health, food and cosmetics industries. Production of this plant has been undertaken in Iran mainly in Isfahan, Kohgiluyeh and Boyerahmad, Golestan and Hamedan provinces. In vitro propagation of plants have higher potential to produce qualified natural products, restoring and preserving of endangered plants, induction of somaclonal variation, industrial reproduction, valuable secondary metabolites and increased active ingredients. Researchers reported successful micropropagation system for five chamomile varieties on MS medium contained 0.01 mg/l NAA and 2.5 mg/l kinetin. The aim of this study was to investigate the effects of stem (with and without node), leaf and cotyledon explants and different plant growth regulators on direct regeneration of German and Shirazi chamomiles. Although the Shirazi chamomile is native to Iran, but German chamomile is Iran non-indigenous cultivar. By our knowledge, there have been no comparison reports about responses of these cultivars to tissue culture. Materials and Methods: This research was performed in the central laboratory of Agriculture Faculty in Yasouj University. Seeds were provided from Pakan-Bazr institute, Isfahan. Chamomile seeds were disinfected by ethanol (70%) for 5-10 min and sodium hypocholorite 3% for 5-12 min and then washed for several times by distilled water. Then, seeds were sown on MS medium for germination. After 2-3 weeks, seedlings were grown and then planted in MS medium supplemented with hormonal combinations of NAA at two levels (0.1 and 0.5 mg/l), kinetin at three levels (2, 2.5 and 3 mg/l) and Zeatin, BAP and 2ip at three levels (0.5, 1 and 1.5 mg/l). The experiment was performed in a completely randomized design with four replications. Factors included explants, cultivars and hormonal combinations. In this experiment, traits such as stem induction percentage, stem length, stem fresh and dry weight root induction percent, root length and stem fresh and dry weight were measured. Statistical analysis was performed using SAS software (version 9.1). In order to test the normality and perform mean comparisons, Minitab 14 and MSTAT-C software was used and excel software was used for drawing diagrams. Results and Discussion: For all traits except stem induction percent and root dry weight, triple interaction of explants, hormonal combinations and cultivar were significant at 1% level. Triple mean comparisons for cultivar, explant and hormonal combinations shows that the highest mean for stem height, stem fresh weight, stem dry weight, root induction percent, root height and root fresh weight was obtained in Shirazi Chamomile cultivar with cotyledon explants in hormonal combinations of 0.1 mg/l NAA and 1.5 mg/l 2ip. The results showed that the best explants in both chamomiles for direct regeneration were stem (whit node) and cotyledon with 78.75% and 75% regenerations, respectively. Also the best genotype and hormone combination were Shirazi chamomile and MS medium supplemented with 1.5mg/l 2ip with 0.1mg/l NAA. To determine the best hormonal combination for root regeneration from direct regeneration, the stems were embedded in medium contained different concentrations of IBA. The first signs of rooting production were observed after 5-7 days. After completing the roots formation (4 weeks after transferring), the rooting percentage, root length, fresh and dry weight of roots were measured. Based upon variance analysis, effect of triple interactions of IBA, explants and cultivar on all traits were not significant, but the effect of IBA for all traits was significant at 1% level. According to the results of mean comparisons for effects of IBA on root traits in direct regeneration of chamomile, the highest percentage of root regeneration (73.75 %), the highest root length (6.60 cm), root fresh weight (174.167 mg) and the highest root dry weight (16.425 mg) were obtained from medium contained 0.5 mg/l IBA. Root differentiation was influenced by auxin (0.5 mg/l IBA) or spontaneously. Regenerated plantlets were transferred to pots contained sterilized soil (3:1:1 mixture of soil: sand: leaf compost). For plant adaptation to natural conditions, glassy caps were used. After adaptation, the caps were removed and the plants were transferred into a growth chamber. Previous studies reported that MS medium supplemented with 0.2 to 1 mg/l of BA and 2 mg/l of NAA induced adventitious bud formation and shoot development in leaf explants of Roman Chamomile. A higher number of adventitious buds were observed at the proximal end of the explants. Plantlets were rooted on MS medium supplemented with 0.1 mg/l of IBA and successfully weaned in vivo. Conclusion: Based on the results of this research, chamomile showed relevant response to direct regeneration.

Impact of Auxins on Vegetative Propagation through Stem Cuttings of Couroupita guianensis Aubl.: A Conservation Approach.

The present study explores the potential of exogenous auxins in the development of adventitious shoots and roots from shoot cuttings of Couroupita guianensis (Nagalingam), a threatened tree. Experiments were conducted to assess the effect of various concentrations of auxins on shoot and root morphological traits of stem cuttings in the greenhouse. Amongst the auxins tested, significant effects on number of shoot buds' induction and their growth were observed with α-Naphthalene Acetic Acid (NAA) treated nodal cuttings. Cent percentage of the stem cuttings of C. guianensis were rooted and shoots were induced when pretreated with 400 mg L−1 NAA for 5 min. Maximum 79% of stem cuttings responded to pretreatment of 300 mg L−1indole-3-butyric acid (IBA) for 5 min, and 75% of stem cuttings induced shoots with 400 mg L−1indole-3-acetic acid (IAA). Presence of at least 5 nodes on stem cuttings was found to be prerequisite for root and shoot induction. About 92% of plants were survived under natural soil conditions raised from the stem cuttings. This is the first report of vegetative propagation of C. guianensis through stem cuttings which could be used for conservation strategy and sustainable utilization of this threatened medicinal tree.

Influence of growth regulators (IBA, BA) on anatomical and morphological changes in bromeliads in in vitro culture

The subject of study were <em>Tillandsia coronata</em> and <em>Guzmania monostachya</em>. The material has been obtained by means of in vitro propagation. The plants were grown for 18 weeks on various kinds of media. Morphological changes were recorded in both species subjected to action of growth regulators. The changes in plant habit were linked with anatomic build. The effect of cytokinin BA upon growth of the stem pith was found, transversely to its axis, through development of numerous meristematic centres and growth and development of adventitious shoots. Leaves of plant grown on media containing cyto-kinin BA were build of a higher number of cell layers of assimilation parenchyma. In plants grown on media with addition of cytokinin the size of stomatal cells was smaller and was accompanied by analogous changes in size of epidermis cells proper. The bushy type of the plants, caused by presence of cytokinin in medium, resulted from the increase of thickness and breadth of leaves and growth of the stem pith, with simultaneous inhibition of cells' elongation. Auxin IBA did not favour the growth of the existing axillary shoots, but stimulated elongation of the stem pith. The stomata of plants of both species grown on media with addition of auxin were bigger. As result of the applied growth regulators a higher frequency of appearance of binucleate cells was found in parenchyma cells of the stem and leaves in both the species studied.

English

High frequency shoot regeneration from in vitro derived leaf explants of Wattakaka volubilis (L.f.) Stapf was achieved through callus mediated organogenesis. Organogenic calli were induced from 20 day old aseptic seedling explants on Murashige and Skoog medium fortified with various concentrations and combinations of plant growth regulators, benzylaminopurine (BAP), α-naphthaleneacetic acid (NAA), indole 3-butyric acid (IBA) and gibberellic acid (GA3). A mean of 8.6 shoots developed from organogenic callus induced from a 2 x 2 cm leaf explants on MS medium with 3% sucrose having 5.37µM NAA in combination with 2.22 µM BAP with 60% induction capacity. Further development of adventitious shoots could be achieved by sub culturing the callus to the same medium with 4.40 µM BAP and 0.288 µM GA3. Organogenesis could not be achieved from the calli of ex vitro derived leaf explants. The developed shoots were rooted on half-strength MS medium with 1% sucrose, 4.90 µM IBA and 0.93 µM kinetin at a frequency of 85%. Well rooted plantlets were then transplanted to vermiculite soil (3:1) mixture in polythene covered pots kept under culture room conditions. Approximately 60% plantlets survived and grew into whole plants. Key words: Adventitious shoots, caulogenesis, organogenic callus-histology.

How timing of sampling can affect the outcome of the quantitative assessment of plant organogenesis

Growth in plant cell or organ size, mass or number over time can be described mathematically by a sigmoidal growth curve with different phases characterized by different growth rates. Therefore, the timing of sampling strongly influences the quantitative outcome of a study and is of great importance if the efficacy of a protocol is to be evaluated. The use of different explants can also influence the timing (or speed) of the developmental outcome, but the impact is not as great as the timing of sampling. In this study, two plant species (an orchid and apple) were used to demonstrate the role of sampling time for evaluating tissue culture experiments, and its impact on the conclusions drawn there from. Using protocorm-like bodies (PLBs) of hybrid Cymbidium Twilight Moon ‘Day Light’ (Orchidaceae), the development of newly formed PLBs was assessed and quantified at seven time intervals: 10, 20, 30, 45, 60, 90 and 120 days. The optimal timing lay between 45 and 60 days, just prior to the PLB forming a shoot. In addition, using two apple (Malus×domestica) scions with different regeneration abilities (easy-to-regenerate ‘Royal Gala’ and difficult-to-regenerate ‘Freedom’), the development of adventitious shoots on leaf segments was assessed after 5 culture intervals: 28, 35, 42, 49 and 63 days. The effect of genotype and the position of the source leaf on the quantitative outcome of adventitious shoot regeneration on leaf explants are presented. With such wide margins of interpretation for both species, caution should be taken by researchers who extrapolate beyond what is reported in a paper for one genus, species or cultivar for application to other germplasm, even if within the same phylum.

In vitro organogenesis of rangpur lime

Rangpur lime (Citrus limonia Osbeck) in vitro organogenesis was studied based on explant type and cytokinin culture media supplementation. Four explants types collected from epicotyl or hypocotyl regions of in vitro germinated seedlings were evaluated. The epicotyl-derived explants consisted of epicotyl segments and the hypocotyl-derived explants consisted of the entire hypocotyl segment, the hypocotyl segment attached to a cotyledon fragment, and the hypocotyl segment divided longitudinally. The explants were cultured on EME culture medium supplemented with benzylaminopurine (0, 0.5, 1.0, or 1.5 mg L-1). The evaluation was performed after 6 weeks. Best results considering both the explant responsiveness and number of shoots developed per explants were obtained when epicotyl segments-derived explants were evaluated. Considering the explant responsiveness of hypocotyl segments-derived explants no difference was detected between the entire hypocotyl segment and the hypocotyl segment attached to a cotyledon fragment. Moreover, the percentage of responsive explants decreased when hypocotyl segments divided longitudinally were tested. No difference was detected for the number of shoots developed per explant considering the three types of hypocotyl-derived explants. Culture media supplementation with BAP was not essential for Rangpur lime in vitro organogenesis. However, adventitious shoot development was stimulated in concentrations between 0.5 - 1.0 mg L-1.

Establishment of an in vitro plant regeneration protocol for Casuarina cunninghamiana Miq. via indirect organogenesis

An in vitro plant regeneration protocol via indirect organogenesis from morphogenetic callus was established for Casuarina cunninghamiana Miq. Effects of plant growth regulator NAA (naphthaleneacetic acid) and BAP (6-benzylaminopurine), sucrose and AgNO3 on callus induction, adventitious bud differentiation and shoot development were examined. Explants used were epicotyl fragments from 45-day-old seedlings. The largest callus (4.29 mm in diameter) was obtained after 1 month on a basic culture medium consisting of Murashige and Skoog ½ macro- and full strength micro- elements, Nitsch and Nitsch vitamins, supplemented with 0.54 μM NAA, 3.30 μM BAP, and 30 g L−1 sucrose. The calli were subcultured in the same medium above for 2 months. They were then cultured for another 2 months for adventitious bud differentiation and shoot development. The highest mean adventitious bud differentiation, number of shoots formed per callus and number of shoots ≥2 cm long per callus (47.50%, 27.38 and 4.75, respectively) were achieved on the above medium modified with NAA at 0.27 μM and supplemented with AgNO3 1 mg L−1. Shoots were successfully rooted without plant growth regulator and the rooted plantlets survived and grew normally. This protocol for in vitro plant regeneration provides a tool not only for vegetative propagation but also for plant genetic transformation and gene function studies of C. cunninghamiana.

In vitro organogenesis in some citrus species

In vitro organogenesis of Citrus was studied for the genotypes Citrus sinensis cv. 'Natal', C. limonia, C. volkameriana, and C. aurantium, with the use of epicotyl segments-derived explants, cultured in MT salts and vitamins medium supplemented with different concentrations of 6-benzylaminopurine (BAP - 0.0; 0.5; 1.0; 1.5 or 2.0 mg L-1). For the recalcitrant genotypes C. limonia and C. aurantium the in vitro organogenesis was also studied with internodal segments-derived explants, cultured in MT salts and vitamins medium supplemented with 0; 0.5; 1.0; 2.0, or 4.0 mg L-1 of BAP. The efficiency of culture medium supplementation with the combination of BAP (0.0; 1.0, or 2.0 mg L-1) and NAA (1-naphthaleneacetic acid - 0.0; 0.3, or 0.5 mg L-1) in the development of adventitious shoots was evaluated for C. aurantium. Culture medium supplementation with BAP is not essential for the adventitious shoots development in the four genotypes studied when epicotyl segments-derived explants are used. In general, culture media supplementation with BAP decreased the percentage of responsive explants excepted for C. sinensis cv. 'Natal' and C. limonia when the concentrations of 1.5 and 2.0 mg/L were used. The presence of cytokinin, in concentrations up to 2 mg/L, stimulated the in vitro organogenesis when internodal segments-derived explants were used for C. limonia and C. aurantium. For C. aurantium no adventitious shoots developed in explants (internodal segments) cultured in basal culture medium, without BAP supplementation. Although no statistic differences could be detected, culture media supplementation with the combination of BAP and NAA favored the development of adventitious shoots in C. aurantium. The best concentration of NAA varied according to BAP concentration. The results presented herein, show that Citrus in vitro organogenesis depends on the interaction of culture medium composition, explant differentiation level, and genotype.

Adventitious shoot regeneration from stem internode explants of Verbena officinalis L., a medicinal plant

Verbena officinalis L. (vervain) is a medicinal plant that shows several biological activities, including antimicrobial, antiinflammatory, analgesic, neuroprotective, hypnotic/sedative, gastroprotective, hepatoprotective, anticancer, cicatrizant, and antioxidant. This report describes an efficient plant regeneration system for V. officinalis via adventitious shoot development from stem internode and petiole explants. Stem internode explants were more effective than petiole explants in terms of both the number of shoots per explant and the percentages of explants forming shoots. Increasing benzyladenine (BA) concentrations steadily increased shoot formation up to 13.32 µM, but 22.22 µM BA caused a sharp decrease. The highest number of shoots (17.1 shoots per explant at 100% frequency) was obtained when 13.32 µM BA was combined with 5.71 µM indole-3-acetic acid (IAA). Rooting of the regenerated shoots was readily achieved when multiple shoots were singled out and cultured on medium containing varying concentrations of different auxins [IAA, indole-3-butyric acid (IBA), 2,4-dichlorophenoxyacetic acid (2,4-D), or naphthalene acetic acid (NAA)]. IBA was more effective in terms of the number of roots developed, producing a mean of 7.1 roots per shoot at 4.92 µM, whereas IAA was more effective for the frequency of shoots developing roots: 100% of the shoots rooted at 5.71 µM IAA. More than 90% of the regenerants survived through the hardening off process, when they were transferred to foam cups and kept under growth room conditions for 2 weeks before finally being moved to room conditions at low humidity. Approximately 3 months after the transfer to room conditions, the flowering of the regenerated plants could be observed.

The phytochemical and pharmacological profile of Persea americana Mill

Over the past decades, herbal medicine has become a thing of global significance with medicinal and economic implications. Wide spread use of herbs throughout the globe has raised serious concerns over its quality, safety, and efficacy. Thus, exact scientific assessment has become a precondition for acceptance of herbal health claims. Persea americana Mill. (avocado) is a tree, native to central America, cultivated in tropical and subtropical climates around the world, belonging to the family Lauraceae, is widely used in Ayurveda and evidence-based phototherapy. There are 3 principal races or groups of avocado: Mexican, Guatemalan, and West Indian named for the areas where they were originally cultivated. The plant is used in traditional medicine for the treatment of various ailments, such as monorrhagia, hypertension, stomach ache, bronchitis, diarrhea, and diabetes. Peptone, b-galactoside, glycosylated abscisic acid, alkaloids, cellulose, polygalacto urease, polyuronoids, cytochrome P-450, and volatile oils are reported to be present in this plant. Biotechnologic approaches show that modified MS medium supplemented with 1.0 mg benzyladenine/L, 0-1mg Indole Butyric Acid/L, 0.1 mg Gibberalic Acid 3/L was optimum for adventitious shoot development. In the present review, an effort has been made to study the different aspects of P. americana Mill.

Indirect regeneration of the Cancer bush (Sutherlandia frutescens L.) and detection of l-canavanine in in vitro plantlets using NMR

The present study reports a simple protocol for indirect shoot organogenesis and plant regeneration of Sutherlandia using rachis and stem segments. Different concentrations (0.0–68.08 μmol l−1) of thidiazuron (TDZ) were used for callus induction and shoot organogenesis. The highest percentage of callus formation (97.5%) and the highest percentage of explants forming shoots (88.8%) were obtained from rachis explants cultured onto Murashige and Skoog (MS) medium (Murashige and Skoog, Physiol. Plant. 15:473–495, 1962) supplemented with 45.41 μmol l−1 TDZ. Scanning electron microscopy demonstrated the early development of adventitious shoots derived from callus cultures. Shoot clusters were further developed and grown in MS hormone-free medium. The presence of l-canavanine was determined by thin-layer chromatography and confirmed after column fractionation using silica gel and nuclear magnetic resonance spectroscopy. Individual shoots were rooted on different concentrations and combinations of MS salt strength and IBA. Half-strength MS salt medium supplemented with 24.6 μmol l−1 IBA was optimal for root induction in which 78% of shoots were rooted. The in vitro plants were successfully acclimatized in a growth chamber with a 90% survival rate.

Development of in vitro shoot cultures of strawberry (Fragaria × ananassa Duch.) ‘Senga Sengana’ and ‘Elsanta’ under the influence of high doses of gibberellic acid

Abstract In this study, the influence of gibberellic acid (GA3) on strawberry in vitro shoot culture growth and development was investigated. ‘Senga Sengana’ and ‘Elsanta’ clones were grown on the medium recommended by Boxus (1999), supplemented with BA (0.5 mg dm-3), IBA (0.1 mg dm-3), glucose (40.0 g dm-3) and GA3 (0.1 - control, 1.0, 2.0, 5.0, 10.0 mg dm-3). In general, gibberellic acid improved axillary shoot elongation and reduced the growth of callus as well as the formation of roots and the development of adventitious shoots. GA3 applied at a concentration of 1.0-2.0 mg dm-3 significantly increased the number of axillary shoots (mainly crown shoots), whereas under higher (5.0-10.0 mg dm-3) doses it stimulated the development of runners. It seems that a new method of strawberry micropropagation based on the multiplication of axillary crowns and runners, which could also reduce the risk of domination of in vitro cultures with adventitious shoots, might be elaborated

An efficient in vitro regeneration system for Lythrum salicaria

This report describes an efficient plant regeneration system for the medicinal plant Lythrum salicaria via direct adventitious shoot development from leaf and stem explants. Leaf explants were much more responsive to regeneration than stem segments. Of the hormonal combinations tested, those involving thidiazuron (TDZ; 0.1, 0.3 or 0.5 mg dm-3) were more effective than the combinations of other hormones and 0.1 mg dm-3 TDZ combined with either indole-3-acetic acid (IAA) or indole-3-butyric acid (IBA) was the most productive. Rooting was readily achieved when multiple shoots were singled out and cultured on medium containing different auxins. IAA was the most effective on root development in terms of both the number of roots per shoot and the frequency of rooted shoots. More than 90 % of the regenerants survived after hardening for four weeks at gradually decreased air humidity.