Single-node Cuttings Research Articles

Adaptability of Buckwheat in vitro

The research goal was to study the morphogenesis of common buckwheat plantlets obtained using different stressors in vitro. The research object was common buckwheat variety Izumrud – single-node cuttings (1.0-1.5 cm in length; two-three lowest internodes) of the plantlets that were obtained by subculturing on a hormone-free MS medium and of the lines that showed tolerance to CuSO4 Å~ 5H2O (161 and 184 mg/l) at the Laboratory of Agricultural Biotechnology. Selective media were prepared based on the Murashige and Skoog medium supplemented with a zinc salt (ZnSO4 Å~ 7H2O) at concentrations of 808, 909, 1010, 1111, 1212, and 1313 mg/l. To evaluate the morphological characteristics of the studied genotypes, their parameter values were calculated relative to the control and expressed as percentage. The genotypes were compared in the following groups depending on the exposure to a certain stressor: group 1 – the genotypes obtained without exposure to copper, group 2 – the genotypes obtained on the media containing the copper salt at a concentration of 161 mg/l, and group 3 – the genotypes obtained on the media containing the copper salt at a concentration of 184 mg/l. Plants from different groups demonstrated dissimilar growth rates under the toxic conditions caused by the studied concentrations of zinc. The morphological parameter values of the copper-tolerant plants (groups 2 and 3) were significantly higher than those of the plantlets obtained without exposure to copper. The plantlets tolerant to CuSO4 Å~ 5H2O (161 and 184 mg/l) showed a heightened resistance to the selective factor (Zn) as evidenced by their high regeneration and survival rates (95.7-100%).

Emergence and Development Vigour of Yam Seedlings from Tissue Culture Generated Single Node Cuttings

Emergence and Development Vigour of Yam Seedlings from Tissue Culture Generated Single Node Cuttings

Impact of Selected Plant Growth Regulators on Rooting Response of Stem Cuttings of Psidium guajava L.

Guava can be propagated vegetatively through layering, cutting and grafting, in addition to seeds. Among the propagation techniques, cuttings have gained popularity because they produce results in a shorted span of time. Rooting is an essential step in the propagation of guava through cuttings. Nowadays, the most popular technique for growing cuttings in a misty environment is the use of plant growth regulators, especially auxins such as Indole-3-Butyric Acid (IBA) and Naphthalene Acetic Acid (NAA) that promote root growth. The present study was undertaken to assess the influence of plant growth regulators on the rooting of diverse stem cuttings from guava cv. Arka Kiran under mist chamber conditions at the Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu. Two plant growth regulators, IBA and NAA were employed at various concentrations. These regulators were applied to single-node cuttings with one leaf, double node cuttings with two leaves, and herbaceous cuttings. The highest rooting percentage (55.10%), the duration for bud sprouting (21.13 days), and number of leaves (4.83) were observed in single-node cuttings treated with IBA at a concentration of 3000 ppm concentration. Single-node cuttings treated with IBA at 3000 ppm exhibited superior rooting and sprouting performance compared to Naphthalene Acetic Acid (NAA). Among the three stem cuttings, single-node cuttings with one leaf proved to be the most effective for rapid multiplication.

Organogenesis versus somatic embryogenesis pathway efficiencies in in vitro propagation of white and water yams

AbstractThe primary goal of this study was to compare the multiplication rates of yam varieties propagated through organogenesis and somatic embryogenesis (SE). Callus was induced from axillary bud explants of three genotypes of Dioscorea rotundata (Asiedu, Ekiti2a, and Kpamyo) and two genotypes of Dioscorea alata (Swaswa and TDa2014) cultured in Murashige and Skoog (MS) medium containing 9.1 µM 2,4-dichlorophenoxylacetic acid and 5.4 µM naphthaleneacetic acid. Plantlets were regenerated in MS containing 4.4 µM benzylaminopurine and 34 µM uniconazole-P through SE. Single-node cuttings of the five genotypes were grown in MS for 8 wk via organogenesis. The SE and organogenesis regenerants were acclimatized and potted in a 2 (propagation techniques (PTs)) × 5 (genotypes) factorial arranged in a completely randomized design (r = 10). The multiplication ratios (MR), number of tubers (NoT) of the SE, and organogenesis regenerants were collected and analyzed using ANOVA, and means were separated using DMRT (P ≤ 0.05). The SE and organogenesis MR ranged from 1:2 (TDa2014) to 1:8 (Asiedu) and 1:4 (Asiedu) to 1:5 (Ekiti2a and TDa2014), respectively. The NoT differed among genotypes, ranging from 1.15 ± 0.49 (Swaswa) to 2.45 ± 1.39 (Asiedu), and between PTs, ranging from 1.42 ± 0.70 (SE) to 1.86 ± 1.11 (organogenesis). The optimum propagation pathway was genotype-specific.

Biological method of single-node cuttings for budburst in five fig cultivars subjected to artificial chilling

Fig orchard expansion requires knowledge of the thermal requirements of genotypes available in different climatic regions. The budburst of fig cultivars was assessed by biological single-node cutting and exposure to artificial chilling. Cuttings from five cultivars were collected during two crop seasons, subsequently packaged in a horizontal position in a cold chamber (8 ± 0.5ºC), and artificially chilled for 0, 40, 80, 120, and 160h. Cuttings were preserved under controlled conditions (23 ± 1°C, RH 85%, and 16h photoperiod). The variables evaluated were the budding velocity, average time and final rate of sprouting, vigorous shoot rate, and average time to leaf opening. The single-node cutting test allowed the assessment of dormancy, which is influenced by the accumulation of chilling in each crop season. The average time and final budding rate varied depending on the temperature requirements for budding. The cultivars were classified on an increasing scale according to their chilling requirements as follows: Pingo de Mel < Roxo de Valinhos < Brown Turkey < White Genova < Troyano. The traditional cultivar in Brazil is Roxo de Valinhos, but all of the cultivars studied had the potential to diversify the fig orchards in this region.

Promoting Rooting and Vegetative Growth in 41 B Vine Rootstock Cuttings with Encapsulated Nano Silver and IBA Applications

Globally, viticulture is carried on by grafting onto vine rootstocks obtained by hybridizing different vitis species or on their own roots due to their tolerance to biotic and abiotic stresses, especially phylloxera (Daktulosphaira vitifoliae). Sustainable regeneration of vineyard areas and new vineyard establishments require significant amounts of vine saplings each year. In addition to hormonal applications, nano products are also tested in the production of high quality vine nursery material. In this study, single nodal cuttings prepared from the vine rootstock 41 B (Vitis vinifera L. cv. Chasselas × Vitis berlandieri) in the resting period were used as plant material. The effects of encapsulated nano silver particles (AgNPs, 0.5 mg L-1 and 1 mg L-1), and IBA (0 and 1 g L-1) applications produced by green synthesis with cv. Öküz Gözü grape seed extract and AgNO3 on promoting rooting and vegetative growth in 41 B vine rootstock cuttings were evaluated in this study. AgNPs and IBA applications promoted rooting of cuttings, and vegetative growth of rooted cuttings. Applications increased shoot length, shoot diameter, number of nodes, fresh and dry weights of roots and shoots, and the highest value among these was achieved by the 1 mg L-1 AgNPs application. Leaf area and chlorophyll content (SPAD value) were determined by 1 g L-1 IBA application. AgNPs and IBA treatments resulted in increased rooting and vegetative growth compared to control. In conclusion, 1 mg L-1 AgNPs was recommended for vine propagation material and sapling producers as nano promotors for rooting and vegetative growth of 41 B rootstock cuttings.

Factors affecting in vitro tuberization of potato

BackgroundPotato (Solanum tuberosum L.) is one of the most economically important annual vegetable crops. Microtubers can be produced, stored around year and directly transported to market without transferring to fresh media and without acclimatization. Thus reducing the field cycle to obtain sufficient number of seed potatoes and a high level of healthy materials. The aim of this study was to investigate effects of different combinations and concentrations of growth regulators i.e., kinetin (2.5 mg/l) and coumarin (20, 40 and 60 mg/l) alone or in addition to varied concentrations of sucrose (30, 60 and 90 g/l) on in vitro tuberization of potato (Solanum tuberosum) cv. Diamount.ResultsThe plantlets were propagated using single-node cuttings cultured on Murashige and Skoog medium containing 0.04 mg/l kinetin and 1.0 mg/l IAA. Shoots (6–7 nodes) from the previous step were cultured into medium supplemented with a factorial combination of sucrose concentrations (30, 60 and 90 g/l), coumarin concentrations (0, 20, 40, and 60 mg/l) and two concentrations of kinetin (0 and 2.5 mg/l). Our results showed that kinetin – induced medium have slightly effect to improve tuberization in vitro. But when kinetin was combined with sucrose, this effect was better when raised sucrose concentration from 30 or 60 to 90 g/l. The highest percentage of tuberization after 8 weeks, highest number of microtuber were obtained with high concentration of sucrose (90 g/l) together with dark condition, at 18–20 °C. Also, the highest concentration of sucrose significantly increased the fresh weight of microtuber. In case of coumarin, results revealed that it has important effect on tuber initiation especially with concentrations 20 mg/l and 40 mg/l; otherwise, the initiation period was minimized after adding kinetin. So, the plantlets must be continuously incubated in coumarin –induce medium plus kinetin for 8 weeks to affect the tuberization response. Also, all the other characters of tuberization process on coumarin-inducing medium could be improved by increasing sucrose concentration to 9 g/l.ConclusionsGenerally, results pointed out that the treatment which consists of kinetin (2.5 mg/l) plus 90 g/l sucrose and 20 mg/l coumarin has the best characteristics of in vitro micro-tuberization.

Effect of arbuscular mycorrhizal inoculation on growth, mineral nutrient uptake, photosynthesis and antioxidant activities of black pepper cuttings

Arbuscular mycorrhizal (AM) fungi are one of most important soil microorganisms that can form mycorrhizal symbiosis with most of the terrestrial plants. In the present study, the effect of arbuscular mycorrhizal fungi inoculation on root colonization, growth, nutrition, photosynthetic gas exchange and antioxidant activities of black pepper cuttings were evaluated under polyhouse conditions. The single node cuttings of black pepper were grown in the presence and absence of AM combinations for 150 days under poly house. AM inoculated plants showed significantly higher mycorrhizal root colonization (95%) and spore numbers (312/50 g of sample). The effect of AM fungi was more prominent in improving root biomass than above ground biomass. Nutrient accumulations were higher in AM inoculated plants rather than uninoculated black pepper plants. Amount of acid phosphatase and dehydrogenase activity were significantly higher in AM inoculated soils. Net photosynthetic rate and stomatal conductance of AM colonized black pepper leaves were found to be significantly greater than uninoculated plants. The influence of AM was more prominent on poly phenol oxidase and β-glucanase activity in leaves than roots. In principal component analysis the scatter plot revealed variations of the effects of arbuscular mycorrhizal fungi on growth of black pepper cuttings. Based on these results, AM inoculation at the earlier stage of plant development could improve symbiosis, and increased plant growth in the nursery which may improve the performance after planting in the field.

Creation of Variation through In-vitro Mutagenesis using Gamma radiation in Rose (Rosa hybrida L.) Variety ‘Lửa’

Rosa hybrida L. var. Lửa has been one of the most important roses for a long time and is most often used for ornamental purposes in Sadec city, Dong Thap province. The study aimed to induce variation through in-vitro gamma-ray irradiation in the rose variety ‘Lửa’ for further improvement in rose breeding. In-vitro single node cuttings (25 in-vitro cuttings per treatment with four replications) were irradiated with different doses of γ-rays (0, 5, 10, 15, 20, 25, or 30 Gy) using a 60Co source (India) at Da Lat Nuclear Research Institute. The γ-irradiated explants were then cultured aseptically on Murashige and Skoog’s basal medium supplemented with 1.0 mg/L BAP to induce multiple shoots, shoot proliferation, and acclimatization at Division of Vegetables, Flowers and Landscaping of Southern Horticultural Research Institute (SOFRI). The LD50 dose was determined at 20 - 25 Gy treatments and these doses affected the multiplication rate, growth in-vitro, and ex-vitro survival rate. Three types of mutants with altered or novel flower color in comparison to the original flower color were isolated, such as Type 1 with orange-pink (Red 52C), Type 2 with pink (Red 54B), and Type 3 with Red 45AB with Red 54B bicolor.

Role of IAA and Primary Metabolites in Two Rounds of Adventitious Root Formation in Softwood Cuttings of Camellia sinensis (L.)

The type of adventitious root formation of tea softwood cuttings is different from that of single node cuttings. In addition to the callus at the base of cuttings, the adventitious roots are also formed in the upper cortex of softwood cuttings. In order to find out the similarities and differences between the above two types of adventitious roots of softwood cuttings and the influencing factors for the differences, an integrated analysis of plant hormones, untargeted metabolomics, and transcriptomics of the softwood cutting stems at different positions is performed. The phytohormone results show that IAA plays a leading role, and a high ratio of in vivo auxin to GA3 or ABA facilitated root formation. The ratios of IAA/GA3 and IAA/ABA in the upper and base rooting parts of cuttings are both higher than the middle non-rooting transition zone. Differences in metabolites indicate that 73 metabolites are involved in the formation of adventitious roots in cuttings. Compared with the middle non-rooting transition zone, most saccharides are downregulated in the upper and base rooting parts of softwood cuttings, and the saccharides in the base rooting parts of cuttings are more consumed than that in the upper rooting parts. Most organic acids in the callus at the base of cuttings show an upward trend, while those in the upper rooting parts show a downward trend. Furthermore, coniferyl alcohol is the key metabolite for adventitious root formation in the upper and base rooting parts of cuttings. Transcriptome results show 1099 differentially expressed genes (DEGs) are obtained, and KEGG enrichment analysis show that these DEGs are significantly enriched in phenylpropanoid biosynthesis, plant hormone signal transduction, and flavonoid biosynthesis pathways. Based on weighted gene co-expression network analysis (WGCNA), two key modules which have a highly positive correlation with IAA are identified. In summary, maintaining the balance of endogenous hormones and sufficient nutritional elements is very important for adventitious root formation in tea plants. Clarifying the material basis of softwood cutting rooting of tea plant is of great significance to improve the cutting survival rate of tea plant (especially difficult rooting varieties) and shorten the breeding cycle.

Expressing the Saccharomyces cerevisiae SUC2 gene encoding invertase apoplastic localization in the transgenic potato (Solanum tuberosum L.) does not contribute to microtubers production of identical physiological age

Study was aimed at assessing the role of apoplastic invertase in synchronization of the microtuber formation in potato plants in vitro. A non-transgenic potato (Solanum tuberosum L.) plants (hereinafter nonTPs) and a line of potato plants, which expressed the SUC2 gene of Saccharomyces cerevisiae encoding invertase apoplastic localization under the control of the B33 promoter of the patatin gene (hereinafter TPs), was used to achieve this purpose. Cell divisions in the axillary meristems of single-node cuttings were synchronized by exposing to 7°C for 24 h in a MS medium (without agar). After the low-temperature, the synchronization (LTS) of proportion of simultaneously dividing cells in meristems of nonTPs was four-fold greater than without chilling. The LTS did not change the number of dividing cells in the axillary meristems of TPs. The LTS contributed to an increase in the mass and size of microtubers in both potato lines. All microtubers of nonTPs were of physiological maturity. At the same time, microtubers of TPs were physiologically immature, with high glucose content. During the tuber formation, the activity of acidic invertases in microtubers of TPs was higher than that of nonTPs. Microtubers of TPs were larger than the nonTPs, more hydrated with low starch amount. Propably glucose accumulated in the microtubers of the TPs may act as a signal to trigger cell division. It indicates the regulatory function of apoplastic invertase and sugars. The high activity of apoplastic invertase plays a negative role in the production of potato microtubers of identical physiological age.

Soil Water Content Directly Affects Bud Burst Rate in Single-Node Cuttings of Perennial Plants

The use of single-node cuttings of shoots as explants to study bud dormancy and its physiology under controlled conditions is a common practice in grapevine (Vitis vinifera L.) or other perennial plant research. In particular, this method has been extensively used to understand the effect of different chemicals on bud dormancy and bud burst. However, the soil water content in those experiments is usually not reported and its relevance is often neglected. Here, we observed that an unevenly distributed soil water content in a tray containing multiple explants results in an uneven pattern of bud burst within the same treatment. Thus, we hypothesised that soil water content can dramatically affect bud burst. To investigate this, we first established that fresh single-node cuttings were able to transport water into the buds. We then tested the rate of bud burst at different water treatments (35%, 55%, 70%, 85%, and 100% of field capacity; FC). We observed a clear dependence of bud burst on water, in which, at very low levels of water, bud burst does not occur; after 35% FC, bud burst rate increases with water content until around 85% FC; and, from 85% FC, bud burst rate becomes independent of water content. These data highlight the critical importance of monitoring soil water content in any bud burst assay in perennials. Finally, we provide a detailed protocol for determining and controlling field capacity and other soil water content indicators.

Dynamic of blueberry buds dormancy in a region of low chill occurrence

Several cultivars of blueberry were introduced in the colder regions in Brazil, but presented varied vegetative and reproductive growth, due to the heterogeneity of adaptation to the regional climate. The objective of this research was to determine the dormancy dynamics of blueberry buds grown in a region of low chill occurrence. Four methods of bud dormancy evaluation were used: biological test of single node cuttings, dormancy index, tetrazolium test and Tabuenca test. The dormancy of floral and vegetative buds of the cultivars Bluebelle, Climax, Delite and Powderblue of the Rabbiteye group was studied in collections every two weeks from April 26 to July 21. In the evaluated period there were only 76 h of temperatures below 7.2° C. The biological test and the dormancy index were viable methods for the dynamic evaluation of buds dormancy. The tetrazolium test was efficient to predict the exit of the endodormancy of floral and vegetative buds, but the Tabuenca test was efficient to predict the exit of floral buds dormancy only for the cultivars of less intense dormancy. The cultivars Bluebelle and Powderblue presented better adaptation to the conditions of low cold occurrence, with well defined installation and overcoming of the dormancy. The cv. Delite is more susceptible to budding heterogeneity and the cv. Climax is the least indicated to the region.

Potato phytopathogene bank and in vitro seed farming: illumination, medium

The investigation of light spectrum influence on growth and development of potato single node cuttings was conducted. Regionized cultivars were involved into the study. Apical meristems were used as explants for microplants creation and cultivated on Murashige-Skoog medium with adding. Microplants were exposed to three light treatments: red LEDs, blue LEDs and white luminescent lamps. It was shown, that red light is not suitable for potato single node cuttings cultivation in vitro under light intensity of 45 µmol photons/m2s. Red and blue light increased the rate of cuttings rhisogenesis. The maximum of nodes per plant developed under blue and white light. The influence of genotype on node quantity was detected. Tuleevskiy cultivar had maximum nodes per microplant and considers being the most perspective for micropropagation, Favorit cultivar – minimum. Microtuberization was obtained on the node cultivation medium in the presence of 1 mg/l IAA and 0.04 mg/l kinetine. The minimum weight and number of microtubers were appropriate to the samples cultivated on hormonal medium. The screening of potato tubers and plant cuttings, which had been collected across Krasnoyarsk Territory, for phytopathogenes presence, was conducted. Alternaria and Fusarium genera dominated among detected micromycetes. Isolates of Botrytis, Aspergillus, Penicillium, Trichothecium genera were recovered.

KONSERVASI TANAMAN LADA (Piper nigrum L.) SECARA IN VITRO

<p><strong>In vitro conservation of black pepper (Piper nigrum L.)</strong></p><p>Black pepper (Piper nigrum L.) is one of the economically im¬ potant spices. The major constraint in black pepper cultivation and conservation in ield is foot rot disease caused by Phytopthora capsici which could cause plants die. Conservation of black pepper germplasms as living collections in ield is risky due to pests and natural disaster. The experiment on in vitro cop ervation of black pepper var. LDL was conducted al the laboratory of Plant Genetic Resources and Breeding, Research Institute for Spice and Medicinal Crops (RISMC) Bogor from April 1998 to Maret 1999. Single node cuttings from sterile culture were used as explains. The explains were cultured on Murashige and Skoog (MS) medium on full and half strength concentration supplemented with paclobutrazol (paclo) (0, 1, 3 and 5 mg/1). The experiment was performed in a randomized complete block design arranged factorially with 10 replications. The result showed that the medium supplemented with paclo on both full MS and MS A medium could suppress vegetative growth until 12 months. There was no signiicant interaction between medium and paclo on shoot initiation. The effect was signiicant on shoot height, number of leaves and culture performances. Increasing paclo concen¬ tration caused higher suppression of plant growth. MS A medium supplemented with paclo 5 mg/1 showed the slowest growth with shool height 2.10 cm and number of leaves 9. Culture performance was fresh, with green leaves and vigorous. Advcntive shoots were able to regenerate on the medium supplemented with BA 0.3 mg/1. In vitro conservation of black pepper with paclo did not change plant regeneration ability. Therefore, this technique may be used as an altenative method for black pepper conservation.</p>

English

Vegetatively propagated crops are exposed to pests every growing season, providing them with the opportunity to feed on the plants and transmit diseases. Meristem culture is an important method to clean for viruses to restore high yields. Media optimizations with different concentrations and combinations of 6-benzylamino purine (BAP) and Naphthalene Acetic Acid (NAA) were tested for their effects on shoot initiation from meristems. This was followed by regeneration and shoot multiplication from nodal cuttings in five elite varieties of sweet potato. There was a highly significant genotype (variety) x environment (media) interaction for all experiments. Concentrations and combinations of BAP and NAA significantly affected the percentage of meristem survival/regeneration and subsequent shoot multiplication. The best combination of the plant growth regulators was NAA (0.1 mg/L) and BAP (1.0 mg/L). For further propagation, shoot numbers per single nodal cuttings were significantly affected by BAP concentrations (p < 0.05) and genotypes. The medium which gave maximum numbers of shoots was ½ MS media supplemented with BAP (2.5 mg/L) and GA3 (0.5 mg/L). The tallest shoots, with the highest number of internodes, suitable for transfer to soil, was obtained from ½ MS media without any growth regulators for all of the cultivars.   Key words: Media, meristem, multiplication, regeneration, shoot, sweet potato.

Dual Role of Gibberellin in Perennial Shoot Branching: Inhibition and Activation.

Shoot branching from axillary buds (AXBs) is regulated by a network of inhibitory and promotive forces, which includes hormones. In perennials, the dwarfed stature of the embryonic shoot inside AXBs is indicative of gibberellin (GA) deficiency, suggesting that AXB activation and outgrowth require GA. Nonetheless, the role of GA in branching has remained obscure. We here carried out comprehensive GA transcript and metabolite analyses in hybrid aspen, a perennial branching model. The results indicate that GA has an inhibitory as well as promotive role in branching. The latter is executed in two phases. While the expression level of GA2ox is high in quiescent AXBs, decapitation rapidly downregulated it, implying increased GA signaling. In the second phase, GA3ox2-mediated de novo GA-biosynthesis is initiated between 12 and 24 h, prior to AXB elongation. Metabolite analyzes showed that GA1/4 levels were typically high in proliferating apices and low in the developmentally inactive, quiescent AXBs, whereas the reverse was true for GA3/6. To investigate if AXBs are differently affected by GA3, GA4, and GR24, an analog of the branch-inhibitor hormone strigolactone, they were fed into AXBs of single-node cuttings. GA3 and GA4 had similar effects on GA and SL pathway genes, but crucially GA3 induced AXB abscission whereas GA4 promoted outgrowth. Both GA3 and GA4 strongly upregulated GA2ox genes, which deactivate GA1/4 but not GA3/6. Thus, the observed production of GA3/6 in quiescent AXBs targets GA1/4 for GA2ox-mediated deactivation. AXB quiescence can therefore be maintained by GA3/6, in combination with strigolactone. Our discovery of the distinct tasks of GA3 and GA4 in AXB activation might explain why the role of GA in branching has been difficult to decipher. Together, the results support a novel paradigm in which GA3/6 maintains high levels of GA2ox expression and low levels of GA4 in quiescent AXBs, whereas activation and outgrowth require increased GA1/4 signaling through the rapid reduction of GA deactivation and subsequent GA biosynthesis.

Tempo of gene regulation in wild and cultivated Vitis species shows coordination between cold deacclimation and budbreak

Dormancy release, loss of cold hardiness and budbreak are critical aspects of the annual cycle of deciduous perennial plants. Molecular control of these processes is not fully understood, and genotypic variation may be important for climate adaptation. To gain greater understanding of these processes, single-node cuttings from wild (Vitis amurensis, V. riparia) and cultivated Vitis genotypes (V. vinifera ‘Cabernet Sauvignon’, ‘Riesling’) were collected from the vineyard during winter and placed under forcing conditions. Cold hardiness was measured daily, and buds were collected for gene expression analysis until budbreak. Wild Vitis genotypes had faster deacclimation and budbreak than V. vinifera. Temperature-sensing related genes were quickly and synchronously differentially expressed in all genotypes. Significant changes in the pattern of expression changes for eight major metabolic and hormone related pathways were seen across all genotypes. Downregulation of ABA synthesis appears to play an important role in loss of cold hardiness and budbreak in all genotypes. This role was validated through an observed halt in cold hardiness loss of ‘Riesling’ buds treated with exogenous ABA. The gene expression cascade that occurs during deacclimation and budbreak phenology of fast (wild) and slow (cultivated) grapevines appears coordinated and temporally conserved within these phenotypes.

In vitro propagation of a useful tropical bamboo, Thyrsostachys siamensis Gamble, through shoot-derived callus

We established a protocol for mass propagation of Thyrsostachys siamensis Gamble in vitro culture via callus formation. Single node cuttings were placed in Murashige and Skoog (MS) medium with benzyl adenine (BA) concentrations ranging from 0 to 44.40 μM. Although multiple shoots formed in all BA treatments, optimum shoot formation occurred at 11.10 μM BA. The MS medium for optimum callus induction from the multiple shoots contained 11.3 μM of 2,4-dichlorophenoxyacetic acid (2,4-D), 4.65 μM kinetin, and 1.96 μM indole-3-yl-butyric acid (IBA). The highest number of shoots regenerating from the callus was obtained in MS medium containing 11.1 μM N6-BA and 3.43 μM IBA. Shoot clusters of 3–5 shoots were rooted on MS medium supplemented with 26.85 μM 1-naphthaleneacetic acid for 3 weeks, and were then transferred onto MS medium without plant growth regulators for 1 week. This protocol can be used for gene manipulation in a breeding program, germplasm preservation, and mass propagation of the bamboo.

Promoted Growth and Development of Carnation Plantlets In Vitro by Ventilation and Combined Red and Blue Light

In this study, the principal objective was to investigate the effect of light quality and vessel ventilation on the growth and development, physiology, activities of antioxidant enzymes, and contents of mineral nutrients of carnation (Dianthus caryophyllus L.) ‘Marble Beauty’. Single node cuttings stuck into the plant growth regulator (PGR)-free MS medium in containers covered with caps with or without a ventilation filter were cultured first four weeks under white and then additional four weeks under either white (control), blue, red, or red + blue light emitting diodes (LEDs) for 56 days. Interestingly, a ventilated culture condition not only reduced the percentage of the hyperhydricity, but also increased the total chlorophyll content (Chl a + Chl b) of the plantlets as compared to the non-ventilated condition. In addition, blue LEDs produced plantlets with the greatest number of shoots and red LEDs produced plantlets with the greatest shoot length. The quality of plantlets was improved under a ventilation condition. Besides, under a ventilated condition, red + blue LEDs raised APX activity, and blue LEDs not only raised the activity of the CAT, but also increased tissue contents of such elements as K, Ca, Mg, Zn, Mn and Fe. The red LEDs increased contents of B and Si under a ventilated condition, and Na accumulation under a non-ventilated condition. Thus, including blue or red LEDs as the light source in a ventilated culture condition will produce plantlets of carnation ‘Marble Beauty’ in vitro with improved quality.