High-affinity nitrate uptake by rice (<Emphasis Type="Italic">Oryza sativa</Emphasis>) coleoptiles

Nitrate uptake by rice coleoptiles was evaluated using ¹⁵N-nitrate in relation to the expression of high-affinity nitrate uptake-related genes, OsNRT2s (OsNRT2.1–2.4) and OsNAR2s (OsNAR2.1 and 2.2). Apparent nitrate uptake by coleoptiles was about one-sixth of that by hydroponically cultured seedling roots. Real-time RT-PCR analysis revealed that OsNRT2.1, a root-specific key gene of inducible high-affinity transport system for nitrate, was most strongly induced in coleoptiles following nitrate supply initiation, while other OsNRT2s and OsNAR2s showed modest induction. These results suggest that rice coleoptiles may have high-affinity transport systems for nitrate similar to roots, and can be model organs for nutrient uptake by submerged plant shoots.     

Micropropagation of the endangered <Emphasis Type="Italic">Kniphofia leucocephala</Emphasis> Baijnath

Summary The species, Kniphofia leucocephala is extant at only one location, Langepan, KwaZulu-Natal in South Africa, where the population is threatened by afforestation and possibly grazing. Consequently, a continuous culture system was established as part of a program for the propagation and re-introduction of plants into the wild. The efficiency of the system in terms of shoot multiplication and, particularly, the frequency and rate of root initiation was strongly influenced by the concentration of benzyladenine in the shoot multiplication medium. The optimum shoot multiplication medium for subsequent root initiation contained 2 mgl⁻¹ (8.9 μM) benzyladenine alone. The shoots were successfully rooted and acclimatized. Approximately 200 shoots can be produced from one shoot after five 4-wk cycles. Thus, large numbers of plantlets can be propagated in this continuous culture system, serving conservation interests.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of an endangered plant species, <Emphasis Type="Italic">Thermopsis turcica</Emphasis> (Fabaceae)

This report deals with micropropagation of the critically endangered and endemic Turkish shrub, Thermopsis turcica using callus, root and cotyledonary explants. Callus cultures were initiated from root and cotyledon explants on MS medium supplemented with 0.5–20 μM NAA or 2,4-D. The root explants were found to be better in terms of quick responding and callusing percentages as compared to the cotyledons. Organogenic callus production with adventitious roots and shoots were obtained on MS medium with only NAA. The calli obtained with NAA, root and cotyledonary explants were cultured with BA and kinetin (2–8 μM) alone or in combination with a low level (0.5 μM) of 2,4-D or NAA. The best regeneration of shoots from root explants was observed on hormone-free MS medium. NAA with BA or kinetin in the medium improved shoot induction from the calli obtained with NAA. Maximum percentage of shoots (93.3%), maximum number of shoots (6.2) and maximun length of shoots (8.22 cm) were achieved from cotyledonary explants at 4 μM BA and 0.5 μM NAA. The presence of 0.5 μM or higher levels of 2,4-D in shoot induction medium inhibited the regeneration in T. turcica explants. 83% of in vitro rooting was attained on pulsed-IBA treated shoots. The regenerated plants with well developed shoots and roots were successfully acclimatized. Application of this study’s results has the potential to conserve T. turcica from extinction.     

<Emphasis Type="Italic">In vitro</Emphasis> organogenesis of <Emphasis Type="Italic">Pelecyphora aselliformis</Emphasis> erhenberg (cactaceae)

Summary In vitro propagation of Pelecyphora aselliformis, a Mexican cactus which is considered rare and is highly valued in the commercial market, was initiated using seeds as explants. The longitudinal explants from seedlings germinated in vitro were cultivated on Murashige and Skoog medium containing 8.8 μM benzyladenine (BA) or 4.6 μM kinetin at pH 7.0. After 120 d, each explant gave rise to five shoots and this number of shoots increased 20–25% after subculture. The hyperhydricity was similar in both media, but callus formation was lower on the medium with BA. The shoot development, in terms of epicotyl length, and fresh and dry weight after 6 wk, was also recorded. The epicotyl length was similar on shoot-forming media but the quality of shoots was better on media containing BA. In about 1 yr, 500–600 well-defined shoots were obtained. The rooting of shoots was very slow and a vigorous radical system was observed after 1 yr of culture.     

Regeneration and genetic transformation of <Emphasis Type="Italic">Hagenia abyssinica</Emphasis> (Bruce) J.F. Gmel. (Rosaceae) with <Emphasis Type="Italic">rolB</Emphasis> gene

The effects of growth regulators, wounding and antibiotics on regeneration of Hagenia abyssinica were investigated and the rolB gene was introduced into this species by Agrobacterium-mediated transformation. Regeneration was affected by type of growth regulators, wounding and antibiotics. Up to 100% regeneration could be obtained. Three transformed clones (T1, T2.1, T2.2), confirmed by PCR and Southern blot, were obtained only by excluding kanamycin from the selection medium 6 weeks after culture, followed by selection during shoot multiplication. RT-PCR revealed strong expression of rolB gene in shoots and roots of all the transgenic clones, but from leaf samples, it was detected only in T1. Rooting frequency was 77% (T1), 50% (T2.1), 57% (T2.2) and 0% for control shoots on growth regulator-free rooting medium.     

<Emphasis Type="Italic">Agrobacterium</Emphasis> mediated genetic transformation of summer squash (<Emphasis Type="Italic">Cucurbita pepo</Emphasis> L. cv. Australian green) with <Emphasis Type="Italic">cbf-1</Emphasis> using a two vector system

Efficient plant regeneration via shoot tip provided a basis for the optimization of the genetic transformation protocol. Therefore, experiments were conducted to establish an efficient in vitro regeneration protocol in summer squash for genetic co-transformation. 6-benzylaminopurine at 0.05 mg l^−l was found to be optimum concentration of direct regeneration from shoot tip. Effective root system was induced in shootlets in indole-3-aceticacid 0.5 mg l^−l. Two vectors namely pCAMBIA 2200 harboring marker gene nptII and pCAMBIA 0390 harboring gene, encoding C-repeat binding factor (cbf1) were used for co-transformation taking shoot tips as explants from in vitro germinated seeds. Explants were selected after co-cultivation on kanamycin supplemented medium and shoots and roots were induced. The transgenic plants were confirmed by polymerase chain reaction (PCR) and further southern blot analysis confirmed the integration of nptII and cbf1 genes in genome of summer squash with co-transformation efficiency of 0.7 percent.     

<Emphasis Type="Italic">In vitro</Emphasis> organogenesis and antioxidant enzymes activity in <Emphasis Type="Italic">Acanthophyllum sordidum</Emphasis>

The effect of various hormonal combinations on callus formation and regeneration of shoot and root from leaf derived callus of Acanthophyllum sordidum Bunge ex Boiss. has been studied. Proteins and activity of antioxidant enzymes were also evaluated during shoot and root organogenesis from callus. Calli were induced from leaf explants excised from 30-d-old seedlings grown on Murashige and Skoog medium containing 4.52 μM 2,4-dichlorophenoxyacetic acid + 4.65 μM kinetin. Maximum growth of calli and the most efficient regeneration of shoots and roots occurred with 2.69 μM 1-naphthalene acetic acid (NAA), 2.69 μM NAA + 4.54 μM thidiazuron and 2.46 μM indole-3-butyric acid. Protein content decreased in calli and increased significantly during regeneration of shoots from callus. Superoxide dismutase activity decreased in calli comparing to that of seedlings, then increased in regenerated shoots and roots. High catalase activity was detected in seedlings and regenerated shoots, whereas high peroxidase activity was observed in calli and regenerated roots.     

<Emphasis Type="Italic">In vitro</Emphasis> regeneration of medicinal plant <Emphasis Type="Italic">Centella asiatica</Emphasis>

This paper describes multiple shoot regeneration from leaf and nodal segments of a medicinally important herb Centella asiatica L. on Murashige and Skoog’s (MS) medium supplemented with a range of growth regulators. The highest number of multiple shoots was observed on MS augmented with 3.0 mg dm⁻³ N⁶-benzylaminopurine (BAP) and 0.05 mg dm⁻³ α-naphthaleneacetic acid (NAA). Leaf explant showed maximum percentage of cultures regenerating shoots (81.6 %), with the highest shoot number (8.3 shoots per explant) and the shoot length (2.1 cm) whereas, nodal explant showed less number of shoots with callus formation at the base cut end. Successive shoot cultures were established by repeatedly sub-culturing the original explant on a fresh medium. Rooting of in vitro raised shoots was best induced on half strength MS supplemented with 0.5 mg dm⁻³ indole-3-butyric acid (IBA) with highest percentage of shoot regenerating roots (76.8 %) with 3–4 roots per shoot. Plantlets were acclimated in Vermi-compost and eventually established in soil. Contents of chlorophyll, total sugars, reducing sugars and proteins were estimated in leaf tissue from both in vivo and in vitro raised plants. Chlorophyll content was higher in in vivo plants, whereas other three components were higher in in vitro plants.     

Protoplast isolation and culture for somatic hybridization of <Emphasis Type="Italic">Lupinus angustifolius</Emphasis> and <Emphasis Type="Italic">L</Emphasis>. <Emphasis Type="Italic">subcarnosus</Emphasis>

A method for isolation and shoot regeneration from electrofused protoplasts of L. angustifolius and L. subcarnosus was developed. Viable protoplasts were isolated from leaves of in-vitro grown seedlings at an average yield of 6 × 10⁵ protoplasts g⁻¹ fresh weight. Liquid and agarose solidified B5 media were used for protoplast culture. In the liquid-culture system, all tested media, VKM, P1 and KM8p, were applicable for inducing cell division (84% of all tested petri dishes at four weeks) and colony formation. Media containing additional carbohydrates were suitable to produce compact calli with green and brown pigmentations in different combinations. Analysis of callus with molecular markers allowed to identify six somatic hybrids. However, none of the parental-protoplast derived cell colonies could develop shoots. This is the first report on protoplast fusion of L. angustifolius and L. subcarnosus with subsequent shoot regeneration.     

Effect of <Emphasis Type="Italic">cra</Emphasis> gene knockout together with <Emphasis Type="Italic">edd</Emphasis> and <Emphasis Type="Italic">iclR</Emphasis> genes knockout on the metabolism in <Emphasis Type="Italic">Escherichia coli</Emphasis>

To elucidate the physiological adaptation of Escherichia coli due to cra gene knockout, a total of 3,911 gene expressions were investigated by DNA microarray for continuous culture. About 50 genes were differentially regulated for the cra mutant. TCA cycle and glyoxylate shunt were down-regulated, while pentose phosphate (PP) pathway and Entner Doudoroff (ED) pathway were up-regulated in the cra mutant. The glucose uptake rate and the acetate production rate were increased with less acetate consumption for the cra mutant. To identify the genes controlled by Cra protein, the Cra recognition weight matrix from foot-printing data was developed and used to scan the whole genome. Several new Cra-binding sites were found, and some of the result was consistent with the DNA microarray data. The ED pathway was active in the cra mutant; we constructed cra.edd double genes knockout mutant to block this pathway, where the acetate overflowed due to the down-regulation of aceA,B and icd gene expressions. Then we further constructed cra.edd.iclR triple genes knockout mutant to direct the carbon flow through the glyoxylate pathway. The cra.edd.iclR mutant showed the least acetate production, resulting in the highest cell yield together with the activation of the glycolysis pathway, but the glucose consumption rate could not be improved. Dayanidhi Sarkar and Khandaker Al Zaid Siddiquee have contributed equally.     

<Emphasis Type="Italic">In vitro</Emphasis> micropropagation of endangered <Emphasis Type="Italic"> Rhododendron ponticum</Emphasis> L. subsp. <Emphasis Type="Italic">baeticum</Emphasis> (Boissier &; Reuter) Handel-Mazzetti

In vitro propagation of Rhododendron ponticum L. subsp. baeticum, an endangered species present in limited and vulnerable populations as a Tertiary relict in the southern Iberian Peninsula, was attained. Several cytokinin:IAA ratios and a range of zeatin concentrations were evaluated for their effect on shoot multiplication from apical shoots and nodal segments. The type of cytokinin and the origin of the explant were the most important factors affecting shoot multiplication. The highest shoot multiplication rate was obtained from single-nodal explants on medium supplemented with zeatin. Increasing zeatin concentration promotes shoot multiplication independently of explant type, although this effect tends to decrease with higher zeatin concentration. Shoot growth was higher in apical shoots and it was not stimulated by the presence of auxin. A number of experiments were conducted to identify suitable procedures for rooting of in vitro produced shoots. The best results in terms of in vitro rooting were obtained with Andersons modified medium with macrosalts reduced to one-half, regardless of the auxin or its concentration in the medium. Although rooting frequency rose to 97% by basal immersion of shoots in auxin concentrated solution followed by in vitro culture on an auxin-free medium, the survival of the plants after 6 months of acclimatization was poor (50%). Best results (100% rooting and survival) were observed for ex vitro rooting. The micropropagated plants from this study were successfully reintroduced into their natural habitat (87% of survival after 8 months).     

Carbon autonomy of reproductive shoots of Siberian alder (<Emphasis Type="Italic">Alnus hirsuta</Emphasis> var.<Emphasis Type="Italic"> sibirica</Emphasis>)

Carbon autonomy of current-year shoots in flowering, and of current-year shoots plus 1-year-old shoots (1-year-old shoot system) in fruiting of Siberian alder (Alnus hirsuta var. sibirica) was investigated using a stable isotope of carbon, ¹³C. The current-year shoot and 1-year-old shoot systems were fed ¹³CO₂ and the atom% excess of ¹³C in flowers and fruits was determined. The majority of photosynthate allocated to flower buds was originally assimilated in the leaves of the flowering current-year shoots. Of all the current-year shoots on fruiting 1-year-old shoots, only those nearest to the fruits allocated the assimilated photosynthate to fruit maturation. These results indicate that the current-year shoots and 1-year-old shoot systems are carbon-autonomous units for producing flowers and maturing fruits, respectively.     

<Emphasis Type="Italic">AOM3</Emphasis> and<Emphasis Type="Italic"> AOM4</Emphasis>: two MADS box genes expressed in reproductive structures of<Emphasis Type="Italic"> Asparagus officinalis</Emphasis>

The MADS box genes participate in different steps of vegetative and reproductive plant development, including the most important phases of the reproductive process. Here we describe the isolation and characterisation of two Asparagus officinalis MADS box genes, AOM3 and AOM4. The deduced AOM3 protein shows the highest degree of similarity with ZAG3 and ZAG5 of maize, OsMADS6 of rice and AGL6 of Arabidopsis thaliana. The deduced AOM4 protein shows the highest degree of similarity with AOM1 of asparagus, the SEP proteins of Arabidopsis and the rice proteins OsMADS8, OsMADS45 and OsMADS7. The high level of identity between AOM1 and AOM4 made impossible the preparation of probes specific for one single gene, so the hybridisation signal previously described for AOM1 is probably due to the expression of both genes. The expression profile of AOM3 and AOM1/AOM4 during flower development is identical, and similar to that of the SEP genes. Asparagus genes, however, are expressed not only in flower organs, but also in the different meristem present on the apical region of the shoot during the flowering season: the apical meristem and the three lateral meristems emerging from the leaf axillary region that will give rise to flowers and lateral inflorescences during flowering season, and to phylloclades and branches during the subsequent vegetative phase. The expression of AOM3 and AOM1/AOM4 in these meristems appears to be correlated with the reproductive function of the apex as the hybridisation signal disappears when the apex switches to vegetative function.     

Salicylic acid and salicylic acid glucoside in xylem sap of <Emphasis Type="Italic">Brassica napus</Emphasis> infected with <Emphasis Type="Italic">Verticillium longisporum</Emphasis>

Salicylic acid (SA) and its glucoside (SAG) were detected in xylem sap of Brassica napus by HPLC–MS. Concentrations of SA and SAG in xylem sap from the root and hypocotyl of the plant, and in extracts of shoots above the hypocotyl, increased after infection with the vascular pathogen Verticillium longisporum. Both concentrations were correlated with disease severity assessed as the reduction in shoot length. Furthermore, SAG levels in shoot extracts were correlated with the amount of V. longisporum DNA in the hypocotyls. Although the concentration of SAG (but not SA) in xylem sap of infected plants gradually declined from 14 to 35 days post infection, SAG levels remained significantly higher than in uninfected plants during the whole experiment. Jasmonic acid (JA) and abscisic acid (ABA) levels in xylem sap were not affected by infection with V. longisporum. SA and SAG extend the list of phytohormones potentially transported from root to shoot with the transpiration stream. The physiological relevance of this transport and its contribution to the distribution of SA in plants remain to be elucidated.     

<Emphasis Type="Italic">In vitro</Emphasis> flowering of <Emphasis Type="Italic">Perilla frutescens</Emphasis>

This study investigated the factors affecting in vitro flowering of Perilla frutescens. The shoots regenerated from cotyledonary and hypocotyl explants cultured on Murashige and Skoog (MS) medium supplemented with benzyladenine (BA) and indole-3-acetic acid, each at 0.5 mg l⁻¹, were excised and transferred to MS medium containing 30 g l⁻¹ of sucrose, 8.25 g l⁻¹ of ammonium nitrate, and 1.0 mg l⁻¹ of BA. After 40 d of culture, 86.2% of shoots flowered and most of which self-fertilized in vitro and produced mature fruits with viable seeds. These seeds were germinated and plants were grown to maturity and flowered in soil under greenhouse conditions. The in vitro flowering system reported in this study may facilitate rapid breeding of P. frutescens and offers a model system for studying the physiological mechanism of flowering.     

Overexpression of <Emphasis Type="Italic">AtATM3</Emphasis> in <Emphasis Type="Italic">Brassica juncea</Emphasis> confers enhanced heavy metal tolerance and accumulation

The eucalypt Corymbia torelliana × C. citriodora is planted widely in India, Brazil and Australia although plantation establishment has been limited by inadequate seed supply and low amenability to propagation via cuttings. This study optimised node culture and organogenic culture methods for in vitro propagation of Corymbia hybrids by identifying explant position (topophysic) effects on rooting, shoot elongation and shoot proliferation. Strong, negative morphogenic gradients in shoot elongation and proliferation capacity were evident from the cotyledonary node to the fourth or fifth node of seedlings when their nodes were transferred to node culture (without benzyladenine). These topophysic effects were related to differences in rooting capacity of individual nodes. Root formation in node culture was associated with formation of long multi-nodal axillary shoots, and so higher rooting of shoots from the cotyledonary node or first true-leaf node was associated with higher shoot proliferation. However, all nodes were equally capable of shoot proliferation in organogenic culture (with 2.2 μM benzyladenine), where rooting and rapid stem elongation did not occur. Most shoots (61–100%) from both node culture and organogenic culture were converted to plantlets, with plantlet conversion and primary root number not differing significantly among explant node positions. The strong topophysic effect in node culture, combined with the lack of a topophysic effect in organogenic culture, provides for an optimised clonal propagation system based on segregation of nodes from the same seedling into separate node and organogenic culture pathways.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation from young and mature explants of thyme (<Emphasis Type="Italic">Thymus vulgaris</Emphasis> and <Emphasis Type="Italic">T. longicaulis</Emphasis>) resulting in genetically stable shoots

An efficient in vitro propagation protocol, applicable both to young and mature explants of two Thymus spp., results in genetically stable plantlets. In vitro-grown shoot tips of Thymus vulgaris L. were exposed to cytokinins (6-benzyladenine, kinetin, and thidiazuron) alone or in combination with auxins, gibberellic acid (GA₃) and/or silver nitrate in order to optimize in vitro shoot proliferation. Optimum shoot proliferation (97% regeneration rate, with 8.6 shoots produced per explant) was obtained when semi-solid Murashige and Skoog (MS) medium was supplemented with 1 mg L⁻¹ kinetin and 0.3 mg L⁻¹ GA₃. Rooting of the shoots was easily obtained on semi-solid MS medium that was either hormone-free or supplemented with auxins. However, the best root apparatus (92.5% rooting rate, with 19 adventitious roots per shoot) developed on MS medium supplemented with 0.05 mg L⁻¹ 2,4-dichlorophenoxyacetic acid. Genetic stability was confirmed in the in vitro-germinated mother plant as well as the shoots that underwent two, four, six, eight, or ten cycles of in vitro subculturing by random amplified polymorphic DNA (RAPD) analysis. When applied to the micropropagation of mature shoot tips of T. longicaulis C. Presl subsp. longicaulis var. subisophyllus (Borbás) Jalas, the optimized in vitro propagation protocol resulted in a 97.5% shoot regeneration rate, with five shoots formed per explant, and 100% rooting. Rooted plantlets of both species were transferred to 250-mL plastic pots and successfully acclimatized by gradually reducing the relative humidity.     

Micropropagation of ornamental <Emphasis Type="Italic">Prunus</Emphasis> spp. and GF305 peach,a <Emphasis Type="Italic">Prunus</Emphasis> viral indicator

A micropropagation approach was developed for nine ornamental Prunus species, P. americana, P. cistena, P. glandulosa, P. serrulata ‘Kwanzan’, P. laurocerasus, P. sargentii, P. tomentosa, P. triloba, P. virginiana ‘Schubert’, commercially important in North America, and GF305 peach, commonly used for Prunus virus indexing. The micropropagation cycle based on proliferation of vegetative tissues includes establishment of tissue culture through introduction of shoot meristems in vitro, shoot proliferation, root induction and plant acclimatization steps and can be completed in 5 months. A meristem sterilization protocol minimized bacterial and fungal contamination. Multiple shoot formation in ornamental Prunus was obtained through the use of 1 mg l⁻¹ 6-benzyladenine. For GF305 peach, alteration in the sugar composition, fructose instead of sucrose, and addition of 1 mg l⁻¹ ferulic acid had a significant impact on the shoot proliferation rate and maintenance of long-term in vitro culture. Rooting and plant acclimatization conditions were improved using a two-step protocol with a 4-day root induction in indole-3-butiric acid (IBA)-containing media with consequent 3-week root elongation in IBA-free media. One-month incubation of rooted shoots in a vermiculite-based medium resulted in additional shoot and root growth and provided better acclimatization and plant recovery. The micropropagation approach can be used for maintenance of the clonal properties for Prunus spp. as well as a protocol to support meristem therapy against viral infection.     

Asymmetric somatic hybridization between UV-irradiated <Emphasis Type="Italic">Citrus unshiu</Emphasis> and <Emphasis Type="Italic">C</Emphasis>. <Emphasis Type="Italic">sinensis</Emphasis>: regeneration and characterization of hybrid shoots

In the present paper, attempts were made to explore the possibility of employing ultraviolet (UV) irradiation in citrus asymmetric fusion for transfer of limited amount of favorable traits from a desirable cultivar to a target one. Exposure of Satsuma mandarin (Citrus unshiu Marc.) embryogenic protoplasts to UV at an intensity of 300 μW cm⁻² led to reduced viability, especially under long irradiation duration. The protoplasts could not grow during culture when they were irradiated for over 30 s. Terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) assay revealed extensive DNA fragmentation in the UV-irradiated protoplasts compared with those without UV treatment. Electrofusion between UV-irradiated protoplasts of Satsuma mandarin (donor) with those of Jincheng (C. sinensis Osbeck, recipient), a local cultivar of superior quality, gave rise to regeneration of several lines of shoots, which failed to root despite enormous endeavors. Ploidy analysis via flow cytometry and chromosome counting showed that four selected shoots were either diploid, triploid or tetraploid. Random amplified polymorphism DNA (RAPD) and amplified fragment length polymorphism (AFLP) confirmed the shoots, irrespective of their ploidy level, as putative somatic hybrids. Cleaved amplified polymorphism sequences (CAPS) demonstrated that the shoots predominantly got their cytoplasmic components, in terms of chloroplast (cp) and mitochondrion DNA, from Jincheng, along with possible recombination of cpDNA in some shoot lines. The current data indicated that UV-based asymmetric fusion could also be employed in citrus somatic hybridization with the intention of creating novel germplasms, which may provide an alternative approach for cultivar improvement.     

Micropropagation of calla lily (<Emphasis Type="Italic">Zantedeschia albomaculata</Emphasis>) via <Emphasis Type="Italic">in vitro</Emphasis> shoot tip proliferation

Summary A method for the micropropagation of Zantedeschia albomaculata is presented using shoot tip proliferation onto Murashige and Skoog (MS) medium supplemented with different plant growth regulator concentrations and combinations. Of the four cytokinins tested, 6-benzyladenine (BA) and thidiazuron (TDZ) were found to be more effective. An optimal concentration of BA (8.87 μM) or TDZ (4.54 μM) developed an average of 3.8 and 3.2 shoots per explant, respectively, but increasing concentrations of cytokinins often led to lower proliferation rate and stunted growth. Addition of auxins to the MS medium supplemented with 8.87 μM BA slightly enhanced multiple shoot formation in the explants. Multiplication of six cultivars of Zantedeschia genus comprising different flower types and colors were tested and achieved using only one regeneration medium (MS+8.87 μMBA+2.46 μM IBA). Different MS medium strength, air temperature (15, 20, 25, and 30°C) and light quality [fluorescent, red + blue, red and blue light provided by a LED (light-emitting diode) system] were used (without phytohormone) with the aim of stimulating in vitro shoot and root development. Half-strength MS or MS and cultures maintained at 25°C were found to be equally suitable for shoot tip culture of Z. albomaculata. Shoot elongation as well as fresh and dry weight were significantly increased when cultures were kept under red or blue light.