Rooting-enhancement of Rosa hybrida for tissue culture propagation

The effect of combinations of auxin sources and concentrations, temperature shifts, light intensity and light reduction on shoot-tips were studied relative to root formation of Rosa hybrida L. ‘Bridal Pink’ propagated in vitro. 2,4-dichlorophenoxyacetic acid alone was almost ineffective, and similarly its combinations with other auxins were less effective than other auxin combinations. While indolebutyric acid (IBA) alone did not stimulate rooting, both indoleacetic acid (IAA) and naphthaleneacetic acid (NAA) were effective. Combinations of NAA and IBA and NAA and IAA were equally effective in stimulating rooting and also enhanced rooting more than IAA, IBA or NAA alone. When root quality is considered, the combination of NAA and IBA was better than that of NAA and IAA.An additive effect on rooting existed between NAA and IAA at most concentrations used. A similar effect was evident between NAA and IBA except when NAA was used at 0.025 mg/l, in which cases synergistic effects were observed. Light reduction to the rooting area, light intensities of 1.0 K lux or lower and holding the cultures for 1 week at 5°C all enhanced rooting.     

Callus induction and culture of Rosa

Leaf and stem explants of Rosa manetti Hort. and R. hybrida L. ‘Tropicana’ were placed on Murashige and Skoog (MS), Schenk and Hildebrandt (SH) and Gamborg and Wetter (1-B5C) media, containing growth regulators, casein hydrolysate (CH) or coconut milk (CM), to determine the optimum conditions for callus initiation and maintenance. The explants were cultured either in dark or in light (2 Klux 16 h/day) at 26±2°C. Friable, fast growing callus was evident after 3 weeks for both rose species on MS + 2.0 mg/l 2,4-D, 0.25 mg/l kinetin (K) and 2.0 g/l CH as well as on SH + 0.5 mg/l 2,4-D, 2.0 mg/l p-CPA and 0.1 mg/l K. Callus initiation occurred sooner on SH than on MS. However, during sub-culture of callus arising on SH, rapid oxidation often occurred, resulting in severe browning of the callus, which made it unsatisfactory for further experimental use. Callus initiation occurred faster in dark than in light, but deteriorated when continuously sub-cultured in the dark regardless of media. Although ‘Tropicana’ initiated callus sooner than R. manetti, very fast growing callus of the latter was obtained when leaf callus was transferred to MS + 2.0 mg/l NAA and 0.5 mg/l BA. Unsuccessful attempts to regenerate callus and induce adventitious shoots on the 2 explants are discussed.     

Meristem culture and micropropagation of a variety of ginger (Zingiber officinale Rosc.) with a high yield of oleoresin

Summary

Meristems of ginger with or without leaf primordia were induced to form shoots on three-quarter strength Murashige-Skoog’s (MS) medium containing sucrose 6%, coconut milk (CM) 20%, ascorbic acid (AA) 100 mg l^?1, glutamine (GL) 400 mg l^?1, activated charcoal (AC) 250 mg l^?1, 6-benzylaminopurine (BAP) 0.5 mg l^?1, indolebutyric acid (IBA) 0.4 mg l^?1 and agar 0.8%. Meristem-derived shoots exhibited consistent multiplication on three-quarter strength MS medium containing sucrose (3%), AA (100 mg l^?1), AC (100 mg l^?1), BAP (4–5 mg l^?1) and agar (0.8%). Liquid media (agitated or static) were less effective than a solid (agar-gelled) medium for micropropagation. Kinetin and naphthalene acetic acid (NAA) incorporated at various levels (0.01–0.8 mg l^?1) with or without added BAP and IBA neither improved plantlet formation nor enhanced shoot multiplication. The in vitro plants were successfully established in vivo and the rhizome yield was comparable with that of plants grown by conventional methods.     

Anther culture of Rosa

Anthers of 2 tetraploid Rosa species (4n=28) were plated on selected basis media, supplemented with various amounts of auxins and kinetin, at different bud stages and using various light conditions. Among the media tested, MS medium with 2.0 mg/l IAA and 0.4 mg/l K was generally the best for anther culture of R. damascena Mill., while medium with 7.5 mg/l IAA and 0.8 mg/l K was found optimum for R. hybrida L. Culture of anthers of R. damascena when a few petals are visible on the flower bud, and of R. hybrida when the flower bud is completely closed, are recommended. Cytological examination showed that most cells of both species had 2n=14 chromosomes and thus were of pollen origin.     

In vitro propagation of ‘Troyer’ citrange from epicotyl segments

Isolated epicotyl, root meristem and root segment tissues of ‘Troyer’ citrange [Poncirus trifoliata (L.) Rat. × Citrus sinensis (L.) Osbeck] were established in continuous culture to compare their regeneration potential. Callus was obtained from these explants on a Murashige—Skoog (MS) medium containing NAA (10 mg l^?1) and BAP (0.1–10 mg l^?1). Formation of shoots from root segments was direct without callus formation on MS medium containing BAP (10 mg l^?1) and NAA (1 mg l^?1). Shoot formation from epicotyl callus occurred on MS medium containing 0.25 mg l^?1 BAP and 0.1 mg l^?1 NAA. Formation of shoots from epicotyl segments occurred on MS medium containing BAP (0.5 mg l^?1) and NAA (0.1–1.0 mg l^?1), while rooting of regenerated shoots occurred in treatments containing 2.0 mg l^?1 NAA alone. This system provides a rapid method for propagation of ‘Troyer’ citrange.     

In vitro vegetative multiplication of Fuchsia hybrida

Rapid development of axillary buds from shoot-tips and nodes of 18 cultivars of Fuchsia hybrida was obtained on solid Murashige and Skoog medium with BAP (1 mg l^?1 and an auxin (0.1 mg l^?1). NAA as the auxin appeared to be more active than IAA or IBA. Vegetative shoots were subsequently isolated and developed up to 15 supplementary axillary shoots on the same solid medium. Agitated and non-agitated liquid media of the same composition were less effective. One-cm long shoots could be rooted in 20 days in the presence of IBA before being transferred to soil.     

A study of the effect of growth regulators and time of plantlet harvest on the in vitro multiplication rate of hardy and hybrid tea roses

The effect of benzyladenine (BA) (0, 0.5, 2.5, 5 and 10 ppm), naphthaleneacetic acid (NAA) (0,0.005,0.01,0.1 and 1 ppm) and time of proliferation (six, eight and ten weeks) on the optimum multiplication conditions for four Rosa hybrida cvs Champlain, John Franklin, John Paul II and Landora were studied. BA and NAA both had a significant effect on the proportion of viable plantlets and on multiplication rates while low or high concentrations of these growth regulators in the medium generally caused a reduction of plant material. The optimum multiplication rate also varied with cultivar and time. Concentrations of NAA above 0.1 ppm decreased the multiplication rate significantly for two of the cultivars. There was no consistent response between multiplication rates and cultivars to concentrations of B A, NAA or even the time of culture, and it is therefore recommended that each of these variates be determined for each cultivar to obtain optimum plantlet yield.     

In vitro propagation of garlic by shoot proliferation

Shoot buds (5–8 mm long), excised from dormant cloves of the New Zealand commercial garlic (Allium sativum L.) and a virus-free French cultivar ‘Rose-de-Kakylis’, proliferated both axillary and adventitious shoots on B-5 basal medium supplemented with 0.5 mg l^?1 isopentenyladenine (2-ip) and 0.1 mg l^?1 naphthaleneacetic acid (NAA). An 8-fold increase in shoot number occurred every 6 weeks. Shoots were readily rooted in B-5 + 0.01 mg l^?1 2-ip + 0.2 mg l^?1 NAA and transferred to pots, where about 70% of the shoots formed established plants. The plants raised by this shoot-proliferation method retained the diploid condition of the parents.     

The Influence of Some Genetic and Environmental Factors on the Concentration of L-Ascorbic Acid in the Tomato Fruit

Summary

An efficient, reproducible protocol has been developed for in vitro multiplication of Sida cordifolia L. High-frequency, multiple shoots (90%) were obtained indirectly from nodal explants. Callus was induced when nodal explants were cultured on Murashige and Skoog (MS) medium supplemented with 0.5 mg l^–1 Kinetin (Kn). These nodal calli were then cultured in order to differentiate multiple shoots on MS medium supplemented with 0.5 mg l^–1 Kn plus 0.5 mg l^–1 naphthaleneacetic acid (NAA). Roots were induced from these multiple shoots following culture on MS medium supplemented with 0.8 mg l^–1 NAA for 4 weeks. Finally, these in vitro plantlets were hardened, acclimatised, and successfully transferred to the field.     

Nitrogen and calcium nutrition of Petunia × hybrida ‘Coral Sea’

The effects of N and Ca nutrition on plant growth and shoot elemental content of Petunia × hybrida Hort. Vilm. - Andr. ‘Coral Sea’ were evaluated. Nitrogen and Ca were applied separately or in combination in three experiments: (1) N at 0, 100, 200 or 400 mg l^?1; (2) Ca at 0, 75, 150 or 300 mg l^?1; (3) N at 0 or 100 mg l^?1 and Ca at 0 or 150 mg l^?1 combined factorially. Shoot and root dry weights, branch length and flower number were highest when plants received 100 mg l^?1 N. Plants treated with 150 mg l^?1 Ca had the highest shoot and root dry weights. Branch length was maximal at 300 mg l^?1 Ca.Nitrogen and Ca interacted to increase shoot dry weights, branch number and length, leaf area and flower number. Increasing N concentrations increased N and decreased P, Mn and Zn shoot contents. Calcium content of shoots increased while N, P and Mg decreased in response to increasing applications of Ca to petunia plants. Minimal N and Ca tissue concentrations for optimal P. × hybrida growth were 3.3 and 0.67%, respectively.     

Rapid in vitro germination of zygotic embryos of fluted pumpkin (Telfairia occidentalis Hook. f.)

Summary

Fluted pumpkin, Telfairia occidentalis, is becoming an important regional vegetable for its food and medicinal uses. The recalcitrant nature of its seed makes conservation difficult and in vitro techniques may be a viable option for conservation. A pilot study was conducted on the effects of different concentrations of a commercial bleach [3.85% (w/v) sodium hypochlorite] for surface sterilisation of T. occidentalis seed. The optimum concentration [25% (v/v)] was then used as a basis to investigate the responses of mature embryonic axes of T. occidentalis to different concentrations of kinetin (Kin; 0, 1.0, or 2.0 mg l^–1) and 1-naphthaleneacetic acid (NAA; 0, 0.5, or 1.0 mg l^–1) combined in a factorial design. The results of the first experiments indicated that commercial bleach at 25% (v/v) resulted in the lowest contamination of explants (10%), with no evident injury to the embryonic axes. The results revealed that root emergence started 3 d after initiation (DAI) only on Murashige and Skoog medium (MS) with no added plant growth regulator (PGR), and that, by 12 DAI, all media supported the rooting of explants. The highest rooting percentage (69%) was observed at 15 DAI on MS medium with 0.5 mg l^–1 NAA, without Kin. However, shoot emergence started at 9 DAI on PGR-free MS medium, on MS with 0.5 mg l^–1 NAA, or on MS plus 1.0 mg l^–1 Kin. The highest shooting percentage (91%) of explants was observed with 0.5 mg l^–1 NAA at 21 DAI. Considering all other growth parameters, MS medium supplemented with 0.5 mg l^–1 NAA was found to be best for the germination of embryonic axes of T. occidentalis.     

Auxins increase the occurrence of leaf-colour variants in Caladium regenerated from leaf explants

Leaf explants of Caladium ‘Pink Cloud’ were cultured in vitro on MS medium containing various auxins (NAA, IBA, IAA, 2,4,5-T and 2,4-D) in combination with cytokinin (BA). NAA gave the most vigorous in vitro propagation of this plant, and only 15% of the plants were leaf-colour variants on the medium containing 0.5 μmol NAA. Leaf colour variation was observed in all plants regenerated on the medium containing 2,4-D at 0.5–4.5 μmol. In hormone-free medium, only a few leaf-colour variants (6%) occurred, but the rate of plant regeneration was very low. Application of 0.5 μmol NAA together with 4.5 μmol BA seemed to be the most appropriate for in vitro propagation of Caladium ‘Pink Cloud’ with only a few leaf-colour variants.     

PLBs induction and clonal plantlet regeneration from leaf segment of commercial hybrids of Phalaenopsis

Induction of Protocorm-like bodies (PLBs) from leaf segments is a clonally propagation technology that used somatic embryogenesis regeneration from in vitro buds of floral stalks, and is a potential alternative for replacement actual low-yield and high-cost clonal propagation of Phalaenopsis orchids. The objective of this work was to evaluate induction of PLBs in leaf segments of two commercial hybrids of Phalaenopsis, arranged in culture media with different combinations of plant growth regulators. The leaf segments (0.4–0.5 cm²) used for PLBs inductions were obtained from young in vitro-induced shoots from inflorescence stalks. They are cultivated in NDM culture media, supplemented with combinations of plant growth regulators Naphthaleneacetic Acid, Thidiazuron and Benzyladenine. The flasks were kept for 60-d in darkness and then for cold white light with photon flux density of 35–40 μmol m^?2 s^?1. The cultivar ‘Ph908’ showed a higher percentage of leaf segments with PLBs (45%) and number of PLBs (25 per leaf segment), in medium containing 0.25 mg L^?1 of TDZ, whereas ‘RP3’ showed only 10% containing PLBs and 2 PLBs per leaf segment in NDM with 1.0 mg L^?1 NAA, 20 mg L^?1 BA and 0.125 mg L^?1 TDZ.     

1-Naphthaleneacetic acid and 6-benzyladenine thinning of a common slender spindle ‘Jonagold’/M.9 apple orchard. I: Dose effects and spray distribution in the crowns

Summary

To find the most appropriate rates of application of plant growth regulator (PGR) thinning-agents for a common slender spindle apple (Malus × domestica Borkh.) orchard, different volumes of dilute 1-naphthaleneacetic acid (NAA) and 6-benzyladenine (BA) were sprayed ha^?1. Mature ‘Jonagold’/M.9 trees, 3.0 – 3.5 m high and 1.2 – 1.5 m wide, planted in a single row system with 3,030 trees ha^?1, were used. Significant thinning was observed in the case of dilute sprays of NAA at 10 mg l^?1, or BA at 100 mg l^?1, to run-off, using 2,000 l ha^?1 or 1,500 l ha^?1; while 1,000 l ha^?1 did not result in sufficient thinning. Thinning using smaller volumes (250, 500, or 750 l ha^?1) was also significant if the concentration of PGR thinner was proportionally higher (i.e., based on the 1,500 l ha^?1 application rate of more dilute sprays of NAA at 10 mg l^?1 or BA at 100 mg l^?1). Spray distribution measurements in the crowns showed better spray deposits when higher water volumes (i.e., more dilute PGR solutions) were sprayed at all positions (bottom, middle, or top) of the canopy. At 2,000 l ha^?1, 54 – 72% coverage of the leaf area was observed; but, at 250 l ha^?1, coverage was only 10 – 21%. The lower 30% of the canopy was covered poorly when smaller volumes of water (250, 500, or 1,000 l ha^?1) were applied. When 1,500 l ha^?1 was sprayed, good coverage of the lower and upper surfaces of the leaves occurred, and no differences in canopy positions were measured. It was concluded that 1,500 l ha^?1 (i.e., dilute PGR) spraying was the most appropriate volume to use when calculating the dose of NAA or BA to be applied ha^?1 to common (3.0 – 3.5 m-high) mature slender spindle apple orchards on M.9 rootstock. This study was part of the ISAFRUIT Smartfruit Project, aimed at improving existing methods for apple crop regulation with more precise use of PGR thinning agents and with minimum impact on the environment.     

1-Naphthaleneacetic acid and 6-benzyladenine thinning of a common slender spindle ‘Jonagold’/M.9 apple orchard. II: Partial tree spraying

Summary

Mature slender spindle ‘Jonagold’/M.9 apple (Malus × domestica Borkh.) trees were thinned using 10 mg l^–1 1-naphthaleneacetic acid (NAA) or 100 mg l^?1 6-benzyladenine (BA) and an axial fan sprayer at a spray volume of 1,500 l ha^?1 applied to the whole canopy, or with smaller volumes, where only the upper half of each canopy was sprayed. Partial spray applications of NAA or BA (at 1,000 l ha^?1, 750 l ha^?1, or 500 l ha^?1) to the upper half of the trees did not cause any reduction in final fruit numbers on the upper half, or on the lower half of each tree. When the whole tree was sprayed to run-off with the same thinning agent, or at 1,500 l ha^?1, successful thinning on both the upper and lower parts of the canopy occurred. Good spray coverage (from 51% to 77%) was also observed on leaves at all canopy positions measured, when whole trees were sprayed at 1,500 l ha^?1.The development of an innovative crop load regulation strategy was an objective of the ISAFRUIT Smartfruit Project.     

Vegetative growth and nutritional status as influenced by auxins and gibberellic acid,and their effect on fruit yield in lemon

Application of 2,4-D and 2,4,5-T at concentrations ranging from 5 to 20 mg l^?1 to 5-year-old ‘Pant Lemon-1’ (Citrus limon Burm) trees reduced the vegetative growth in terms of height, spread, shoot length, number and size of the leaves in the autumn flush. Various NAA treatments (5–20 mg l^?1), however, enhanced growth, but not to the extent that was observed after GA₃ treatments. Application of GA₃ at 10–40 mg l^?1 significantly enhanced all aspects of growth, and the effects were most pronounced at 20 and 40 mg l^?1. Nutritional status of the leaves showed a slight variation in relation to vegetative growth under various treatments.Some 2,4-D- and 2,4,5-T-treatments increased the fruit yield over the control, which could suggest mobilization of foods even at the expense of reduced vegetative growth. On the other hand, NAA, particularly at 10 mg l^?1, increased both vegetative growth and yield, suggesting that the transport of the photosynthates from the leaves to the fruits was not at the expense of new growth extension. Due to excessive growth enhancement under higher concentrations of GA₃ (20 and 40 mg l^?1), comparatively fewer nutrients were translocated to the fruit “sinks”, thereby resulting in a non-significant decrease in yield.     

Physiological response of cauliflower in relation to manganese-boron interaction

Summary

Cauliflower (Brassica oleracea L. var. botrytis) was grown in refined sand at low (0.0011 mg l^?1), normal (0.55 mg l^?1) and excess (5.5 mg l^?1) Mn, each at three levels of B, deficient (0.0033 mg l^?1), normal (0.33 mg H) and excess (3.3 mg l^?1). In Mn deficient cauliflowers a deficiency of B accentuated visible symptoms of Mn deficiency and aggravated the Mn deficiency effects i.e. a decrease in dry matter, leaf Mn, sugars, starch, chlorophyll, Hill reaction and specific activity of aldolase and an increase in the concentrations of proline and inorganic phosphorus. In cauliflowers exhibiting B toxicity symptoms under conditions of excess B, excess Mn increased leaf Mn, sugars, nucleic acids, protein P, nucleic acid P, acid-labile P and leaf B. Excess Mn decreased the concentrations of DNA, protein nitrogen, chlorophyll and activities of peroxidase, aldolase and leaf B, leaf Mn in boron deficient cauliflowers.     

Bioactivities of Some Wild Fruits Grown in Turkey

In this study some bioactive properties of extracts of wild pear (Pyrus elaegnifolia), hawthorn (Crataegus spp.), oriental hackberry (Celtis tournefortii), oleaster (Elaeagnus angustifolia), Japanese crabapple (Malus floribunda), rosehip (Rosa canina), pedunculate oak (Quercus robur), service tree (Sorbus domestica) and firethorn (Pyracantha coccinea) wildly growing in Turkey were investigated. The fruit extracts were analysed in terms of total phenolic content (TPC), antioxidant activities (DPPH and phosphomolybdenum methods) and antimicrobial activity. In the results, TPC, IC50 value of DPPH and IC50 value of phosphomolybdenum for pedunculate oak were 454.35?mg GAE/g d.w., 340.52?mg AAE/g d.w. and 96.52%, respectively. Service tree and firethorn exhibited the lowest TPC (4.11?mg GAE/g d.w.) and IC50 value of DPPH (53.32?mg AAE/g d.w.), respectively. Moreover, antimicrobial activity of oleaster was 2.46%. The hackberry fruit extract had no inhibitory effect against the tested microorganisms whereas pedunculate oak extract (with 10%) had the highest inhibitory effect against Aeromonas hydrophila. Additionally, all the fruit extracts had no antimicrobial activity against the Saccharomyces cerevisiae. In conclusion, wild edible fruit extracts can be used as bioactive material due to their antioxidant and antimicrobial activity in food industry and human nutrition.

     

An efficient method for immature embryo rescue and plant regeneration from the Calli of Ziziphus jujuba ‘Lengbaiyu’

Hybrid breeding of Chinese jujube (Ziziphus jujube) is limited by embryo abortion. Improving the success of embryogenic progeny and immature embryo culture techniques could increase the breeding efficiency of new jujube varieties. We optimised the current immature embryo culture techniques by using immature embryos before the globular stage of Chinese jujube variety Lengbaiyu. The optimal growth media were as follows: for 30-day-old immature embryo growth, MS + IBA 0.8 mg·L^?1 + ZT 0.5 mg·L^?1 + GA₃ 7.0 mg·L^?1 + NAA 0.2 mg·L^?1 + LH 0.5 mg·L^?1 + 5% sucrose, with 22.22% embryonic growth rate and 0.41% plantlet formation rate; and for young embryo differentiation, MS + TDZ (0.8 mg·L^?1) + IAA (0.5 mg·L^?1) + sucrose (3%), with 81.12% differentiation rate. Thus, regeneration via callus induction effectively improved the efficiency of embryo rescue from young immature embryos in Lengbaiyu, which might provide new approaches for breeding Chinese jujube.     

Callus and axillary-bud culture of Vitis vinifera ‘Sylvaner Riesling’

Healthy growth of serially subcultured callus of the grape Vitis vinifera cultivar ‘Sylvaner’ was obtained by incubation at 30° C in continuous light in a defined culture medium containing 2% w/v sucrose, 1.0 mg l^?1 1-naphthaleneacetic acid (NAA) and 0.2 mg l^?1 kinetin (K). Organogenesis was not induced in this callus by alteration in the absolute or relative levels of NAA and K.Continued shoot initiation was obtained by culture of axillary buds in a medium containing 10^?5 M Benzyladenine (BA). Plantlets could be generated from these shoot buds by transfer to media containing 10^?7 M BA or lacking a cytokinin.