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161.
Somatic embryogenesis and plant regeneration from fragments of immature inflorescences and coleoptiles of durum wheat 总被引:4,自引:0,他引:4
Benkirane Hasnae Sabounji Karima Chlyah Averil Chlyah Hassan 《Plant Cell, Tissue and Organ Culture》2000,61(2):107-113
Use of Hypericum perforatum L. has increased in the past few years due to the antidepressant and antiviral activities found in extracts of this plant.
As a result of its potential as a pharmaceutical, a new system was developed for in vitro culture of this species. Leaf explants were inoculated onto MS medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D,
0.45 or 4.5 μM) and 6-benzyladenine (BA, 0.44 or 4.4 μM) or kinetin (0.46 or 4.6 μM). Explants were cultivated under dark
or light conditions to induce callus formation. Callus initiation was observed in all media evaluated and the highest cell
proliferation was obtained from explants cultivated in the presence of 4.4 μM BA and 4.5 μM 2,4-D in the dark. Shoot induction
was obtained from callus induced on 4.6 μM kinetin and 0.45 μM 2,4-D 6 weeks after transferring the callus to a MS medium
supplemented with 4.4 μM BA. Roots were induced from shoots on full and half-strength MS media with or without indolebutyric
acid (IBA, 4.9 μM) and the highest rooting frequencies were obtained on half-strength MS medium, regardless of the presence
of IBA. Regenerated plants were easily acclimated in greenhouse conditions. The procedure reported here allows the micropropagation
of H. perforatum in five months of culture and the proliferation of cell masses which could be used for studies on organic compounds of pharmaceutical
interest.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
162.
163.
Paulo Henrique Pereira Peixoto Fátima Regina Gonçalves Salimena Marcelo de Oliveira Santos Leonardo da Silva Garcia Patrícia Maria de Oliveira Pierre Lyderson Facio Viccini Wagner Campos Otoni 《In vitro cellular & developmental biology. Plant》2006,42(6):558-561
Summary This work describes an efficient micropropagation protocol of Lippia filifolia. Nodal segments cultivation in MS medium supplemented with 6-benzylaminopurine (4.5 μM)/α-naphthaleneacetic acid (NAA; 54nM) induced multiple shoots (in average 27 shoots per explant). Elongated shoots were rooted with NAA (0.11 μM) and they maintained ploidy level of the in vitro produced explants. The basic chromosome number were 2n=2x=24. Regenerated rooted shoots were successfully acclimatized under shading house conditions. This is the first report involving
the establishment of a protocol for shoot multiplication and rooting for endangered L. filifolia, contributing for germplasm preservation of this species. 相似文献
164.
Viswambharan Sarasan Ryan Cripps Marcaret M. Ramsay Caroline Atherton Monica McMichen Grace Prendergast Jennifer K. Rowntree 《In vitro cellular & developmental biology. Plant》2006,42(3):206-214
Summary
In vitro techniques have found increasing use in the conservation of threatened plants in recent years and this trend is likely to
continue as more species face risk of extinction. The Micropropagation Unit at Royal Botanic Gardens, Kew, UK (RBG Kew) has
an extensive collection of in vitro plants including many threatened species from throughout the world. The long history of the unit and the range of plants
cultured have enabled considerable expertise to be amassed in identifying the problems and developing experimental strategies
for propagation and conservation of threatened plants. While a large body of knowledge is available on the in vitro culture of plants, there are limited publications relating to threatened plant conservation. This review highlights the progress
in in vitro culture and conservation of threatened plants in the past decade (1995–2005) and suggests future research directions. Works
on non-threatened plants are also included wherever methods have applications in rare plant conservation. Recalcitrant plant
materials collected from the wild or ex situ collections are difficult to grow in culture. Different methods of sterilization and other treatments to establish clean
material for culture initiation are reviewed. Application of different culture methods for multiplication, and use of unconventional
materials for rooting and transplantation are reviewed. As the available plant material for culture initiation is scarce and
in many cases associated with inherent problems such as low viability and endogenous contamination, reliable protocols on
multiplication, rooting, and storage methods are very important. In this context, photoautotrophic micropropagation has the
potential for development as a routine method for the in vitro conservation of endangered plants. Long-term storage of material in culture is challenging and the potential applications
of cryopreservation are significant in this area. Future conservation biotechnology research and its applications must be
aimed at conserving highly threatened, mainly endemic, plants from conservation hotspots. 相似文献
165.
Hailu M. Aynalem Timothy L. Righetti Barbara M. Reed 《In vitro cellular & developmental biology. Plant》2006,42(5):405-410
Summary
In vitro-stored plant germplasm is usually evaluated by visual analysis of the plant based on subjective characters. To reduce the
variability in these evaluations, we developed a digital-image evaluation system for in vitro-stored plantlets. This study compares the standard visual evaluation system with a digital analysis system to determine if
digital analysis can effectively quantify the health of diverse Humulus germplasm. Eight cultivars of Humulus lupulus L. were stored on standard Murashige and Skoog (MS) medium with iron alone (EDTA chelated) and on MS iron with 100 or 200
mgl−1 sequestrene 138 iron (EDDHA chelated). Digital images of the upper two nodes of each plantlet were evaluated for red, green,
blue, green/red ratio, and modified normalized difference vegetation index (MNDVI=R-G/R+G). Evaluation of each plantlet for
MNDVI values showed consistent significant differences for all treatments only at the upper node. Significant differences
for visual and the MNDVI values among the three iron treatments were observed at the upper node of most of the eight hop cultivars.
Regression analysis of the upper node MNDVI values vs. whole-plant visual ratings showed positive correlations for most cultivars.
Effects of iron treatments on storage duration were also analyzed for both visual and digital systems. There were significant
differences among MNDVI values for plantlets stored on medium with standard MS iron alone (EDTA chelated) and with the addition
of sequestrene 138 iron. In general, the MNDVI value of the upper node correlated well with visual ratings and could be used
to determine the health of in vitro stored hops. 相似文献
166.
M. A. Couceiro F. Afreen S. M. A. Zobayed T. Kozai 《In vitro cellular & developmental biology. Plant》2006,42(3):278-282
Summary Photomixotrophic (Pm) micropropagation systems (ones that use a sugar-containing medium) have been used by many rescarchers
for transplant production of St. John's wort. However, these methods have not yet been adopted for commercial applications,
probably due to the low percentage of regeneration in vitro, and a low growth rate after transplanting ex vitro. In contrast, it is well known that the use of a photoautotrophic (Pa) micropropagation system (one that uses sugar-free
medium) can promote the growth and improve the quality of plantlets in vitro, and enhance the growth during acclimatization for many plant species. In the current study, leafy nodal cuttings were cultured
under Pa conditions and the growth and quality were compared with those cultured under Pm conditions. After 21d of culture,
Pa conditions enhanced the growth and quality of St. John's wort plantlets in vitro, and these plantlets showed faster growth after transplantaing ex vitro compared with those cultured under Pm conditions. 相似文献
167.
Carmen Valero-Aracama Michael E. Kane Sandra B. Wilson Joseph C. Vu Joan Anderson Nancy L. Philman 《In vitro cellular & developmental biology. Plant》2006,42(6):572-583
Summary The photosynthetic and carbohydrate status of an easy-to-acclimatize (EK 16-3) and a difficult-to-acclimatize (EK 11-1) genotype
of Uniola paniculata L. (sea oats), a native dune species of the southeastern US, were evaluated during in vitro culture and ex vitro acclimatization. Net photosynthetic rate was eight times greater for EK 16-3 than EK 11-1 plantlets after ex vitro transfer. In vitro-produced leaves were morphologically similar to ex vitro-produced leaves and exhibited similar photosynthetic competence. EK 11-1 plantlets exhibited greater transpiration rates
at the time of ex vitro transfer than EK 16-3 plantlets. However, the small magnitude of this difference, although significant, indicated that control
of water loss was probably not the main cause for poor acclimatization of EK 11-1 plantlets. Carbohydrate analysis in vitro revealed that EK 16-3 plantlets utilized leaf starch reserves more rapidly than EK 11-1 plantlets. Starch utilization correlated
with the development of leaves with expanded leaf blades during in vitro rooting in EK 16-3 plantlets. After ex vitro transfer, both genotypes exhibited significant decreases of starch and soluble sugar content in shoots and roots. However,
the higher photosynthetic ability of shoots in EK 16-3 resulted in greater accumulation of shoot soluble sugars than EK 11-1
after 2-wk ex vitro culture. After 6-wk in vitro rooting, there were significantly higher chlorophyll and soluble protein contents, ribulose 1,5-bisphosphate carboxylase
(rubisco) and phosphoenolpyruvate carboxylase activities in EK 16-3 than EK 11-1 shoots. These differences also correlated
with the development of anatomical and morphological leaf features in EK 16-3 similar to those of greenhouse-produced leaves. 相似文献
168.
Isolation and characterization of a novel banana rhizosphere bacterium as fungal antagonist and microbial adjuvant in micropropagation of banana 总被引:7,自引:0,他引:7
Ayyadurai N Ravindra Naik P Sreehari Rao M Sunish Kumar R Samrat SK Manohar M Sakthivel N 《Journal of applied microbiology》2006,100(5):926-937
AIM: Isolation and characterization of a bacterial isolate (strain FP10) from banana rhizosphere with innate potential as fungal antagonist and microbial adjuvant in micropropagation of banana. METHODS AND RESULTS: Bacterium FP10 was isolated from the banana rhizosphere and identified as Pseudomonas aeruginosa based on phenotypic, biochemical traits and sequence homology of partial 622-bp fragment of 16S ribosomal DNA (rDNA) amplicon, with the ribosomal database sequences. Strain FP10 displayed antibiosis towards fungi causing wilt and root necrosis diseases of banana. Production of plant growth hormone, indole-3-acetic acid (IAA), siderophores and phosphate-solubilizing enzyme in FP10 was determined. Strain FP10 tested negative for hydrogen cyanide, cellulase and pectinase, the deleterious traits for plant growth. Screening of antibiotic genes was carried out by polymerase chain reaction using gene-specific primers. Amplification of a 745-bp DNA fragment confirmed the presence of phlD, which is a key gene involved in the biosynthesis of 2,4-diacetylphloroglucinol (DAPG) in FP10. The antibiotic produced by FP10 was confirmed as DAPG using thin layer chromatography, high performance liquid chromatography and Fourier transform infrared and tested for fungal antibiosis towards banana pathogens. Procedures for encapsulation of banana shoot tips with FP10 are described. CONCLUSIONS: Strain FP10 exhibited broad-spectrum antibiosis towards banana fungi causing wilt and root necrosis. DAPG by FP10 induced bulb formation and lysis of fungal mycelia. Encapsulation of banana shoot tips with FP10 induced higher frequency of germination (plantlet development) than nontreated controls on Murashige and Skoog basal medium. Treatment of banana plants with FP10 enhanced plant height and reduced the vascular discolouration as a result of Fusarium oxysporum f. sp. cubense FOC. SIGNIFICANCE AND IMPACT OF THE STUDY: Because of the innate potential of fungal antibiosis by DAPG antibiotic and production of siderophore, plant-growth-promoting IAA and phosphatase, the strain FP10 can be used as biofertilizer as well as a biocontrol agent. 相似文献
169.
Rooting of Eucalyptus globulus shoots was influenced by the concentration of the indole butyric acid (IBA) and NH4
+ in the root-induction medium. Optimum plantlet vigor and survival were achieved using low concentrations (1 – 2.5 μM) of
IBA and when NH4NO3 was removed. Removal of NH4
+ also had a significant effect on medium pH, its presence caused a decrease in pH as the culture period proceeded. When different
nitrate compounds (excluding NH4NO3) were used as the nitrogen source, the medium pH was more stable and this was associated with higher root production. The
higher root production, in association with appropriate IBA concentrations, produced plantlets with higher survival and better
growth on transfer to soil.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
170.
Felipe?A.?Vázquez-Flota Víctor?Manuel?Loyola-VargasEmail author 《In vitro cellular & developmental biology. Plant》2003,39(2):250-258
Summary The Scientific Research Center of Yucatán (CICY, for its Spanish acronym) was founded in November 1979 as part of an effort
to decentralize scientific activities from Mexico City. Several of the research programs carried out at CICY make use of plant
tissue culture techniques for their development. For this article, we have reviewed results obtained in research projects
oriented towards basic plant biology questions, as well as towards the micropropagation of economically important species,
and the production of secondary metabolites. 相似文献