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1.
Carmen Valero-Aracama Sandra B. Wilson Michael E. Kane Nancy L. Philman 《In vitro cellular & developmental biology. Plant》2007,43(3):237-246
Net photosynthetic rates (P
n) of easy (EK 16-3) and difficult-to-acclimatize (EK 11-1) sea oats genotypes were examined under the following culture conditions:
(1) photoautotrophic [sugar-free medium, high photosynthetic photon flux (PPF), high vessel ventilation rates and CO2 enrichment, (PA)]; (2) modified photomixotrophic [sugar-containing medium diluted with sugar-free medium over time, high
PPF, and high vessel ventilation rates (PM)]; (3) modified photomixotrophic enriched [same as PM with CO2 enrichment, (PME)]; or (4) conventional photomixotrophic [sugar-containing medium, low PPF, and low vessel ventilation rates
(control)]. Regardless of genotype, plantlets cultured under PA conditions died within 2 wk, whereas under PM and PME conditions,
plantlets increased their P
n. After 6 wk, P
n per gram dry weight was 1.7 times greater in EK 16-3 than EK 11-1 plantlets cultured under PME conditions. In vitro-produced leaves of EK 16-3 plantlets were elongated with expanded blades, whereas EK 11-1 produced short leaves without expanded
blades, especially under control conditions. After in vitro culture, EK 16-3 PME plantlets exhibited the highest dry weights among treatments. EK 16-3 PME and EK 16-3 PM had similarly
high survivability, shoot and root dry weights and leaf lengths ex vitro compared to EK 16-3 control and EK 11-1 PM and PME plantlets. Ex vitro growth, survivability and P
n per leaf area of either genotype were not affected by CO2 enrichment under modified photomixotrophic conditions. These results suggest that growth and survivability of sea oats genotypes
with different acclimatization capacities can be enhanced by optimizing culture conditions. 相似文献
2.
Seon Jeong-Hoon Cui Yong-Yi Kozai Toyoki Paek Kee-Yoeup 《Plant Cell, Tissue and Organ Culture》2000,61(2):135-142
The photosynthetic responses of Rehmannia glutinosa grown under photoautotrophic or heterotrophic conditions in vitro were investigated after transfer to greenhouse conditions. In addition, the changes in carbohydrate content and survival
rates of the plantlets were evaluated. During six days after transplantation, the photosynthetic rate declined and photoinhibitory
impairments represented by decrease of Fv/Fm and chlorophyll content were observed regardless of environmental conditions
in vitro. Excessive transpiration was observed in plantlets grown under heterotrophic conditions during that period. Fructose and
glucose content of the plantlets grown under photoautotrophic conditions increased with time and reached almost the same level
of field grown plants after day 15. Under heterotrophic conditions, in contrast, the content of these sugars decreased continuously
during that period. It is suggested that high survival rate of plantlets grown under photoautotrophic conditions has to be
attributed to improvement of photosynthetic competence by imposed high light intensity and CO2 concentration in vitro. The results strongly suggest that the control of transpiration during early stage after transplantation plays a key role
in the acclimatization process, and photoautotrophic conditions could be a solution to solve the problems associated with
transplantation stress.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
3.
Growth and Photosynthetic Characteristics of Solanum tuberosum Plantlets Cultivated in Vitro in Different Conditions of Aeration, Sucrose Supply, and CO(2) Enrichment 总被引:1,自引:0,他引:1
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Growth characteristics, oxygen exchange, and carbohydrate and chlorophyll contents were determined 30 days after subculturing of single node-derived plantlets of Solanum tuberosum cv Haig cultivated in vitro. Cultivation conditions were: (a) photomixotrophy in closed vessel, (b) photomixotrophy in closed vessel on medium supplemented with silver thiosulfate, (c) photomixotrophy in aerated vessel, (d) photoautotrophy in air, (e) photoautotrophy in CO2-enriched air. In photomixotrophic conditions, aeration of the vessel enhanced sucrose utilization and had a positive effect on plantlet growth. In photoautotrophic conditions, growth of the plantlets was slow in air and was strongly enhanced by CO2 enrichment of the atmosphere. Starch to sucrose ratios were higher in plants grown photoautotrophically than in plants grown with sucrose in the medium. Oxygen exchange characteristics on a chlorophyll basis were similar between the plantlets when measured under moderate light, and resembled those of greenhouse plant leaves. In high light, however, plantlets grown photoautotrophically in a CO2-enriched atmosphere had higher oxygen exchange rates. We concluded from these results that potato plantlets in vitro in conditions (c), (d), and (e) developed C3-plant photosynthetic characteristics, which were in photoautotrophically grown plantlets comparable to those of field-grown plants. 相似文献
4.
To improve large-scale in vitro production of Oplopanax elatus Nakai, we cultured somatic embryo-derived plantlets under a heterotrophic condition (semi-solid culture with sucrose), photoautotrophic
condition (semi-solid culture without sucrose), or modified photoautotrophic condition (liquid culture with forced ventilation).
The plantlets grown under the modified photoautotrophic condition had more leaves as well as higher chlorophyll content, and
higher net photosynthetic rate than those grown under the conventional conditions. Further, the photoautotrophically grown
plantlets acclimatized better and sooner upon ex vitro transplantation than did the conventionally cultured plantlets. Consequently, a photoautotrophic culture method with forced
ventilation is effective for enhancing the growth and acclimatization of O. elatus. 相似文献
5.
Development of a forced ventilation micropropagation system for large-scale photoautotrophic culture and its utilization in sweet potato 总被引:2,自引:0,他引:2
S. M. A. Zobayed C. Kubota T. Kozai 《In vitro cellular & developmental biology. Plant》1999,35(4):350-355
Summary A forced ventilation system has been developed for large-scale photoautotrophic micropropagation of chlorophyllous plants.
The major goal of the system is to provide a uniform supply of CO2 inside a large culture vessel (volume 3480 ml) to achieve uniform growth of the plantlets. The system has been designed such
that sterile nutrient solution can be supplied throughout the culture period, which is essential for long-term culture. Sweet
potato (Ipomoea batatas L. Lam., cv. ‘Beniazuma’) was used as a model plant for photoautotrophic culture with stagnant and nonstagnant nutrient solution
in large vessels. Growth and net photosynthetic rates of the plantlets were compared with those of the plantlets grown in
a small vessel under photoautotrophic conditions (with natural ventilation) and conventional photomixotrophic conditions.
The results indicated that the large vessel with the forced ventilation system was effective for improving growth and uniformity
of the plantlets and the rate of net photosynthesis. The stagnant nutrient solution condition under photoautotrophic forced
ventilation treatment significantly increased the fresh mass of the plantlets; however, percent dry mass was highest in the
treatment with nonstagnant nutrient solution condition. The results demonstrated that the conventional photomixotrophic culture
system can cause seriously inhibited growth and development. 相似文献
6.
Suriyan Cha-um Chaturong Chanseetis Watchara Chintakovid Aussanee Pichakum Kanyaratt Supaibulwatana 《Plant Cell, Tissue and Organ Culture》2011,106(3):435-444
In this study, a rooting protocol was developed for macadamia plantlets with healthy roots and enhanced growth performance,
along with enhanced photosynthetic capability. In vitro-grown shoots rooted in vented vessels containing vermiculite as the
supporting material exhibited 100% frequency of root induction, whereas when shoots were grown in non-vented vessels containing
a solidified Murashige and Skoog (MS) medium, the frequency of root induction was less than 30%. The formation of root with
callus, hyperhydricity, and leaf necrosis was observed in this photomixotrophic closed system. The modification of the vented
photoautotrophic system with different concentrations of CO2 and sucrose were investigated using vermiculite as the supporter. The number of roots, root length, root surface area, fresh
weight, and dry weight were significantly higher in plantlets grown in CO2-enriched (1,000 μmol CO2 mol−1) photoautotrophic conditions. The water content in both root and shoot tissues of plantlets cultured under photoautotrophic
conditions was maximized. In addition, shoot and leaf performances were enhanced in plantlets cultured under CO2-enriched photoautotrophic conditions. The supplementation of sucrose (29–88 mM) to culture media in both ambient and elevated
CO2 conditions affected a reduction in the shoot and root performance of in vitro plantlets. Chlorophyll a, chlorophyll b, and
total carotenoids in the leaf tissues of plantlets acclimatized in CO2-enriched photoautotrophic conditions were enriched, leading to increasing photosynthetic abilities, including chlorophyll
fluorescence and net photosynthetic rate. From this investigation, a root induction protocol was established and the production
of healthy macadamia plantlets was successfully implemented using CO2-enriched photoautotrophic conditions. 相似文献
7.
Summary
In vitro plantlets of Phalaenopsis ‘Happy Valentine’, Neofinetia falcate Hu, Cymbidium kanran Makino, and Cymbidium goeringii Reichb. f. were grown under photoautotrophic [high photosynthetic photon flux (PPF), high CO2 concentration, and increased number of air exchanges] and heterotrophic (low PPF, low CO2 concentration, no air exchanges) culture conditions. After 40 d of culture, a significant difference in plantlet growth was
observed between the two cultures. Total fresh and dry mass were on average 1.5 times greater in photoautotrophic culture
than in heterotrophic culture. Higher net photosynthetic rates were also observed for Phalaenopsis in photoautotrophic culture. In photoautotrophic culture, little difference was observed in air temperature between the inside
and outside of the culture vessel, whereas in heterotrophic culture, air temperature inside the culture vessel was 1–2°C higher
than that outside the culture vessel. Relative humidity inside the culture vessel was remarkably different between the two
cultures: 83–85% in photoautotrophic culture and 97–99% in heterotrophic culture. These results indicated that growth and
net photosynthetic rate of in vitro orchid plantlets were susceptible to the culture environments such as PPF, CO2 concentration, relative humidity (RH), and the number of air exchanges, which would allow a more efficient micropropagation
system for these orchid plants. 相似文献
8.
Cleber Witt Saldanha Caio Gomide Otoni Marcela Morato Notini Kacilda Naomi Kuki Ana Cláudia Ferreira da Cruz Aurélio Rubio Neto Leonardo Lucas Carnevalli Dias Wagner Campos Otoni 《In vitro cellular & developmental biology. Plant》2013,49(4):433-444
The aim of the present study was to evaluate the effects of forced ventilation and CO2 enrichment (360 or 720 μmol mol?1 CO2) on the in vitro growth and development of Pfaffia glomerata, an endangered medicinal species, under photomixotrophic or photoautotrophic conditions. P. glomerata nodal segments showed substantial differences in growth, relative water content and water loss from leaves, photosynthetic pigments, stomatal density, and leaf anatomical characteristics under these different treatments. CO2 enrichment led to increased photosynthetic pigments and reduced stomatal density of in vitro cultivated P. glomerata. A lack of sucrose in the culture medium increased 20-hydroxyecdysone levels, but the increase in CO2 levels did not further elevate the accumulation of 20-hydroxyecdysone. All growth increased in a CO2-enriched atmosphere. In addition, CO2 enrichment, with or without sucrose, gave a lower relative water loss from leaves. This finding indicates that either a photoautotrophic or photomixotrophic system in a CO2-enriched atmosphere may be suitable for large-scale propagation of this species. 相似文献
9.
Mass Propagation of Eucalyptus camaldulensis in a Scaled-up Vessel Under In Vitro Photoautotrophic Condition 总被引:3,自引:0,他引:3
A scaled-up culture vessel was designed for the large-scalephotoautotrophic micropropagation of chlorophyllous plants.The culture vessel (volume 20 l) contained a plug cell traywith 448 plantlets, and had a forced ventilation system to supplyCO2-enriched air. A nutrient-reservoir was connected to theculture vessel from which nutrient solution was circulated tothe culture vessel every 24 h. Nodal leafy cuttings of Eucalyptuscamaldulensis L. were cultured photoautotrophically in thissystem without sugar in the nutrient medium, but with an enrichedCO2concentration and a high photosynthetic photon flux. Thegrowth and the net photosynthetic rate of the in vitro grownplantlets and the survival percentage of the plantlets aftertransplanting to ex vitro conditions were compared with thoseof plantlets grown photoautotrophically under natural ventilationin conventional small culture vessels (Magenta-type vessels;volume 0.4 l). Fresh and dry masses and net photosynthetic ratewere significantly higher in plantlets grown in the scaled-upvessel compared to plantlets grown in the conventional smallvessels (control). The environmental conditions created in thisscaled-up vessel (with forced ventilation) also facilitatedacclimatizationin vitro . Importantly, after transplanting tothe ex vitro condition, plantlets grew well without any specializedexvitro acclimatization treatment. Copyright 2000 Annals of BotanyCompany CO2enrichment, Eucalyptus camaldulensis L., ex vitro, forced ventilation, natural ventilation, photoautotrophic, scaled-up vessel, survival percentage 相似文献
10.
Stomatal characteristics and leaf anatomy of potato plantlets cultured in vitro under photoautotrophic and photomixotrophic conditions 总被引:1,自引:0,他引:1
S. M. A. Zobayed F. Afreen-Zobayed C. Kubota T. Kozai 《In vitro cellular & developmental biology. Plant》1999,35(3):183-188
Summary Potato plantlets (Solanum tuberosum L. cv. Benimaru) were cultured under photoautotrophic (without any sucrose in the nutrient medium and with enriched CO2 and high photosynthetic photon flux) and photomixotrophic conditions (20 g 1−1 sucrose in the medium). Leaf anatomy and stomatal characteristics of the leaves were studied in relation to stomatal size
and density. Leaf diffusive resistance, transpiration rate, and wax content of the leaves were also investigated. In the photoautotrophic
treatment, stomata behaved normally by closing in the dark and opening in the light. The stomatal density increased twofold
compared to that of the photomixotrophic treatment. Relatively thick leaves and an organized palisade layer were observed
and the epicuticulal wax content was remarkably higher in this treatment, i.e., seven times greater than that of photomixotrophic
treatment. In general, higher diffusive resistance of the leaves was observed than under photomixotrophic conditions; also
the resistance increased in darkness and decreased in the light. All these characteristics led the plantlets to have a normal
and controlled transpiration rate, which was exceptionally high in the photomixotrophic treatment throughout the light and
the dark period. 相似文献
11.
Photoautotrophic shoot and root development for triploid melon 总被引:2,自引:0,他引:2
Adelberg Jeffrey Fujiwara Kazuhiro Kirdmanee Chalermpol Kozai Toyoki 《Plant Cell, Tissue and Organ Culture》1999,57(2):95-104
The aim of this investigation was to establish environmental factors which promote growth and photosynthesis of melon (Cucumis
melo L.) shoot buds, in vitro, and determine if photoautotrophic shoots had superior root forming ability in photoautotrophic
environments. Buds from the triploid melon clone ‘(L-14×B)×L-14’ were observed for 21 days after transfer from a multiplication
MS medium with 3% sucrose and 10 μM benzyladenine (BA) to a shoot development medium with 1 μM BA at three levels of sucrose
in the medium (0, 1 and 3%), and light (50, 100 and 150 PPF) and CO2 (500, 1000 and 1500 ppm) in the culture chamber. More shoot buds were observed with 3% sucrose in the medium. Increased light
and CO2 had a positive interaction with shoot proliferation. Fresh and dry weights were greatest at 3% sucrose, 150 PPF light and
1500 ppm CO2. Shoot buds grew more slowly in sugar-free medium, but fresh and dry weight still doubled over 21 days of culture. Net photosynthetic
rates (NPR) of buds were negative after four days in treatment conditions, but became positive after transfer to fresh, sugar-free
medium. Two triploid genotypes of melon were (1) grown in vitro with sugar (photomixotrophic) and without sugar (photoautotrophic),
(2) rooted in sugar-free media, both in a laboratory controlled environment chamber (in vitro) and a greenhouse acclimatization
unit (ex vitro), and (3) compared for subsequent nursery growth in the greenhouse unit. The genotype ‘(L-14×B)×L-14’ produced
more shoots than ‘(L-14×B)×Mainstream’ in both photomixotrophic or photoautotrophic conditions. ‘(L-14×B)×L-14’ rooted as
well from either photoautotrophic and photomixotrophic shoots but ‘(L-14×B)×Mainstream’ rooted less frequently from photoautotrophic
shoots. Seventy-six percent of the shoots in the laboratory controlled environment chamber were able to root photoautotrophically,
whereas 47% of the shoots in the greenhouse acclimatization unit were rooted. Between 77% and 88% of plantlets from all treatment
combinations survived transfer to the nursery. After growth in the nursery, the sizes of plants (fresh weight, dry weight,
leaf area) were the same for either genotype, from either photoautotrophic or photomixotrophic shoots. Nursery plants that
had been rooted in the laboratory controlled environment chamber were larger than those rooted in the acclimatization greenhouse
chamber.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
12.
Environmental control for the large-scale production of plants through in vitro techniques 总被引:11,自引:0,他引:11
Kozai Toyoki Kubota Chieri Ryoung Jeong Byoung 《Plant Cell, Tissue and Organ Culture》1997,51(1):49-56
Leafy or chlorophyllous explants of a number of plant species currently micropropagated have been found to have high photosynthetic
ability. Their growth and development have been promoted on sugar-free medium rather than on sugar-containing medium, provided
that the environmental factors, such as CO2 concentration, light intensity and relative humidity, are controlled for promoting photosynthesis and transpiration of explants/shoots/plantlets
in vitro. Thus, environmental control is essential for promoting photosynthetic growth and development of in vitro plantlets.
Several types of sugar-free (photoautotrophic) culture systems for large-scale micropropagation of plants have been developed.
Advantages of sugar-free over conventional (heterotrophic or photomixotrophic) micropropagation systems are as follows: growth
and development of plantlets in vitro are faster and more uniform, plantlets in vitro have less physiological and morphological
disorders, biological contamination in vitro is less, plantlets have a higher percentage of survival during acclimatization
ex vitro, and larger culture vessels could be used because of less biological contamination. Hence, production costs could
be reduced and plant quality could be improved significantly with photoautotrophic micropropagation. Methods for the measurement
and control of in vitro environments and the beneficial effects of environmental control on photosynthetic growth, development,
and morphogenesis in large-scale production of micropropagated plantlets are presented.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
13.
Culture on sugar medium enhances photosynthetic capacity and high light resistance of plantlets grown in vitro 总被引:4,自引:0,他引:4
I. Tichá F. áp D. Pacovská P. Hofman D. Haisel V. apková C. Schäfer 《Physiologia plantarum》1998,102(2):155-162
The significance of photosynthetic photon flux (PPF) and sugar feeding for the production of plants in vitro is only poorly understood. Nicotiana tabacum L. plantlets were grown photoautotrophically and photomixotrophically (3% sucrose) at two different PPFs (60 µmol m−2 s−1 and 200 µmol m−2 s−1 ) to investigate the effect of these culture parameters on photosynthetic performance and growth. Photomixotrophically‐grown plantlets showed an increase in carbohydrate content, mainly in glucose and fructose. Plant growth, dry matter accumulation and total leaf area were higher under photomixotrophic than photoautotrophic conditions. Not only biomass formation but also photosynthesis was positively affected by exogenous sucrose; the chlorophyll (Chl) content and the light‐saturated rate of photosynthetic oxygen evolution were higher in photomixotrophic plantlets. Photoinhibition occurred in plantlets that were grown photoautotrophically at the higher PPF. It became apparent as a loss in Chl content and photochemical efficiency. Photoinhibited plantlets showed a decrease in the D2/LHCII and CP47/LHCII ratios, suggesting a preferential loss of proteins from the photosystem II (PSII) core. The increased content of xanthophyll cycle pigments in photoinhibited plantlets indicated that also protective mechanisms were activated. Photomixotrophic growth of the plantlets prevented the occurrence of photoinhibitory symptoms. Therefore, we conclude that culture on sugar medium increases not only the photosynthetic potential but also the high light resistance of plantlets grown in vitro. 相似文献
14.
S. M. A. Zobayed F. Afreen T. Kozai 《In vitro cellular & developmental biology. Plant》2001,37(6):807-813
Summary Nodal cuttings of Eucalyptus camaldulensis L. plantlets were cultured photoautotrophically (sugar-free nutrient medium and with enriched CO2 and high photosynthetic photon flux) in a scaled-up vessel (volume 4.0 liters) under forced ventilation (SV-treatment). After
28 d of culture, physiological aspects of the plantlets were compared with plantlets grown photomixotrophically (20 g l−1 sucrose in the medium) in a Magenta vessel (volume 0.4 liters) under natural ventilation (control). In the SV-treatment net
photosynthetic rates were enhanced, normal stomatal closing and opening were observed, and the epicuticular leaf-wax content
was significantly higher than the control. The anatomical study showed well-organized palisade and spongy mesophyll layers
of SV leaves. The SV-treatment also allowed in vitro acclimatization, and after transplanting ex vitro, the transpiration rate and the percent water loss was lower than those of the control and thus the SV plantlets acclimatized
easily ex vitro. 相似文献
15.
Photosynthetic characteristics of Cymbidium plantlet in vitro 总被引:17,自引:0,他引:17
The photosynthetic characteristics of the Cymbidium plantlet in vitro cultured on Hyponex-agar medium with 2% sucrose were determined based on the measurements of CO2 concentration inside and outside of the culture vessels. The CO2 measurements were made with a gas chromatograph at a PPF (photosynthetic photon flux) of 35, 102 and 226 mol m-2 s-1, a chamber air temperature of 15, 25 and 35°C and a CO2 concentration outside the vessel of approximately 350, 1100 and 3000 ppm. The net photosynthetic rates were determined on individual plantlets and were expressed on a dry weight basis. The steady-state CO2 concentration during the photoperiod was lower inside the vessel than outside the vessel at any PPF greater than 35 mol m-2s-1 and at any chamber air temperature. The photosynthetic response curves relating the net photosynthetic rate, PPF, and CO2 concentration in the vessel and chamber air temperature were similar to those for Cymbidium plants grown outside and other C3 plants grown outside under shade. The results indicate that CO2 enrichment for the plantlets in vitro at a relatively high PPF would promote photosynthesis and hence the growth of chlorophyllous shoots/plantlets in vitro and that the plantlets in vitro would make photoautotrophic growth under environmental conditions favorable for photosynthesis.Abbreviations Cin
CO2 concentration in the culture vessel
- Cout
CO2 concentration outside the vessel (in the culture room)
- PPF
photosynthetic photon flux 相似文献
16.
《Environmental and Experimental Botany》1999,41(3):219-230
The effects on growth in super-elevated (1%) CO2 in terms of photosynthetic capability and carbohydrate production were studied in an epiphytic CAM (Crassulacean acid metabolism) orchid plantlet, Mokara Yellow (Arachnis hookeriana×Ascocenda Madame Kenny). The growth of the plantlets was greatly enhanced after growing for 3 months at 1% CO2 compared with the control plantlets (0.035% CO2). CO2 enrichment produced more than a 2-fold increase in dry matter production. The enhanced root growth at 1% CO2 led to a higher root:shoot ratio. Plantlets grown at super-elevated CO2 had higher Fv/Fm values, a higher photochemical quenching (qP) and a relatively lower non-photochemical quenching (qN). CO2 at 1% appeared to enhance the utilization of captured light energy in the orchid plantlets. CO2 enrichment also increased contents of soluble sugars (glucose and sucrose) and starch in the orchid plantlets. The extra starch formed under 1% CO2 did not cause a disruption of the chloroplasts. Chlorophyll content was higher and a clear granal stacking was evident in young leaves and roots of plantlets grown at 1% CO2. An extensive thylakoid system was observed in the young leaf chloroplasts of the CO2-enriched plantlets indicating an improved development of the photosynthetic apparatus when compared to that of the control plantlets. The increased photosynthetic capacity and enhanced growth of the epiphytic roots under CO2 enrichment would facilitate the generation of more photoassimilates and acquisition of essential resources, thereby increasing the survival rate of orchid plantlets under stressful field conditions. 相似文献
17.
Unlike C-3 plants, cacti possess a crassulacean acid metabolism (CAM) physiology that can alter the pattern of carbon uptake
and affect plant growth under artificial environmental conditions, especially in tissue culture. In vitro-derived plantlets of Coryphantha minima grew 7-fold larger than plants cultured under similar ex vitro conditions. Growth regulators incorporated into the culture media during shoot proliferation stage of micropropagation had
a strong influence on this increased growth. Other important factors that contributed to increased growth under in vitro conditions were high relative humidity and sugar in the culture medium. An analysis of gas exchange and daily fluctuations
of malic acid levels revealed an increase in net photosynthetic rate, in terms of carbon assimilation, by in vitro plants compared with that of ex vitro plants. This stimulated photosynthesis in the presence of an external carbon source was unexpected but apparently true for
cacti exhibiting CAM physiology. Unlike CAM plants grown in ex vitro conditions, net CO2 uptake by in vitro-cultured cacti occurred continuously in the light as well as the dark. Once regenerated, cacti were transferred to ex vitro conditions where the normal CAM pathway resumed with a concomitant reduction in growth and CO2 uptake. These results showed that growth of cacti can be considerably accelerated by in vitro culture.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
18.
Summary Explants of sugarcane, a C4 plant, were cultured in vitro for 18d on Floridalite (a solid cube consisting of vermiculite and cellulose fibers) used as supporting material with sugar-free
Murashige and Skoog liquid medium with double-strength KH2PO4, MgSO4, FeSO4, and Na2-EDTA in the vessel with enhanced natural ventilation. CO2 concentration in the culture room was kept at 1500 μmol mol−1 (four times the atmospheric CO2 concentration) during the photoperiod. A factorial experiment was designed with two levels of photosynthetic photon flux
(PPF) and three levels of N (number of air exchanges of the vessel). The results were compared with those in the control treatment (photomixotrophic
culture using sugar-containing agar medium under low PPF and low N). PPF and N showed significant positive effects on the growth of sugarcane plantlets in vitro. In the photoautotrophic (using sugar-free medium) treatments with relatively high PPF (200–400 μmol m−2 s−1) and high N (2–10 h−1), the growth of plantlets was four to seven times greater than that in the control. Also, the culture period for multiplication
and rooting was shortened from 30 d in the control to 18 d or less in the photoautotrophic, high PPF, and high N treatments. Use of porous supporting material in photoautotrophic treatments promoted rooting and plantlet growth significantly. 相似文献
19.
This study reports survival and physiological responses of micropropagated Ceratonia siliqua L. cvs. Galhosa and Mulata plants during ex vitro acclimatization under ambient (AC; 330 mol mol–1) or elevated (EC; 810 mol mol–1) CO2 concentration and a photosynthetic photon flux density of 125 mol m–2 s–1. CO2 enrichment during acclimatization did not improve survival rate that was around 80 % for both treatments. Eight weeks after ex vitro transplantation, photosynthetic capacity and apparent quantum yield in acclimatized leaves were higher in comparison with those in in vitro-grown leaves, without any significant difference between CO2 treatments. Chlorophyll content increased after acclimatization. However, EC led to a decrease in the total amount of chlorophyll in new leaves of both cultivars, compared to those grown at AC. Soluble sugars and starch contents were not markedly affected by growth EC, although starch had significantly increased after transfer to ex vitro conditions. EC induced an increase in the stem elongation and in the effective life of leaves, and a decrease in the number of new leaves. 相似文献
20.
Summary
Lilium Asiatic hybrid ‘Mona’ bulblets were cultured in vitro for 100 d under photoautotrophic (CO2-enriched conditions and without sucrose in the medium) and heterotrophic (non-enriched CO2 conditions and sucrose-supplemented medium) methods and under various levels of photosynthetic photon flux (PPF). Bulblet
growth and net photosynthetic rate (NPR) were analyzed. CO2− and PPF-enriched conditions enhanced the overall growth of bulblets, scale leaves, and roots. Heterotrophic conditions enhanced
bulblet growth but higher PPF levels were inhibitory to the development of scale leaves. These results indicate the CO2− and PPF-enriched conditions (photoautotrophic conditions) are beneficial for the production of high-quality bulblets of Asiatic
hybrid lilies in vitro 相似文献