共查询到20条相似文献,搜索用时 31 毫秒
1.
A. M. Vieitez E. Corredoira A. Ballester F. Muñoz J. Durán M. Ibarra 《Plant Cell, Tissue and Organ Culture》2009,98(2):135-145
North American oak species, with their characteristic strong episodic seasonal shoot growth, are highly problematic for clonal
micropropagation, resulting in the inability to achieve a stabilized shoot multiplication stage. The potential for initiating
and proliferating shoot cultures derived from Quercus alba, Q. bicolor and Q. rubra explants was investigated, and a micropropagation method for these species was developed. Branch segments from 6 to 7-year-old
trees were forced-flushed and the forced shoots were used as source of explants for culture initiation. A consistent shoot
multiplication stage was achieved, in 13 of the 15 genotypes established in vitro, although marked differences occurred in
explants from different genotypes/species. The control of efficient shoot multiplication involved the culture of decapitated
shoots in a stressful horizontal position on cytokinin-containing medium with a sequence of transfers within a 6-week subculture
cycle, which was beneficial to overcoming the episodic character of shoot growth. During each subculture cycle, the horizontally
placed explants were cultured on media containing 0.2 mg l−1 benzyladenine (BA) for 2 weeks with two successive transfers (2 weeks each) to fresh medium with 0.1 mg l−1 BA, giving a 6-week subculture cycle. The general appearance and vigor of Q. alba and Q. bicolor shoot cultures were improved by the inclusion of both 0.1 mg l−1 BA and 0.5 mg l−1 zeatin in the medium used for the second transfer within the 6-week subculture cycle. Addition of AgNO3 (3 mg l−1) to the shoot proliferation medium of Q. rubra had a significant positive effect on shoot development pattern by reducing deleterious symptoms, including shoot tip necrosis
and early senescence of leaves. The three species showed acceptable in vitro rooting rates by culturing microcuttings in medium
containing 25 mg l−1 indolebutyric acid for 48 h with subsequent transfer to auxin-free medium supplemented with 0.4% activated charcoal. Although
an initial 5-day dark period generally improved the rooting response, it was detrimental to the quality of regenerated plantlets.
However, activated charcoal stimulated not only the rooting frequencies, but it also enhanced plant quality, as evidenced
by root, shoot and leaf growth. 相似文献
2.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
3.
Li-Hua Zhu Xiao-Qin Wu Hong-Ye Qu Jing Ji Jian-ren Ye 《Plant Cell, Tissue and Organ Culture》2010,102(1):121-128
A protocol was developed for the micropropagation of Pinus massoniana and mycorrhiza formation on rooted microshoots. Seedling explants were first cultured on Gresshoff and Doy (GD) medium supplemented
with 6-benzyladenine (BA) alone or in combination with α-napthaleneacetic acid (NAA) to stimulate the formation of intercotyledonary
axillary buds. The frequency of axillary bud induction was up to 97% on medium supplemented with 4.0 mg l−1 BA and 0. 2 mg l−1 NAA, and the average number of buds per explant reached up to 5.5 on medium with 4.0 mg l−1 BA and 0.1 mg l−1 NAA. Axillary buds elongated rapidly after being transferred to half-strength GD medium containing activated charcoal (0.1%
w/v). Shoot proliferation was achieved by cutting elongated shoots into stem segments and subculturing on GD medium containing
2 mg l−1 BA and 0.2 mg l−1 NAA. Root primordia were induced in 82% of shoots when transferred to half-strength GD medium containing 0.2 mg l−1 NAA. Root elongation was achieved in a hormone-free GD agar medium or a perlite substrate. Rooted plantlets were inoculated
with the mycelium of ectomycorrhizal fungus Pisolithus tinctorius and the formation of ectomycorrhiza-like structures was achieved in vitro. 相似文献
4.
5.
Iyyakkannu Sivanesan Mi Young Lim Byoung Ryong Jeong 《Plant Cell, Tissue and Organ Culture》2011,107(2):365-369
A simple and efficient protocol was developed for somatic embryogenesis from leaf and petiole explants of Campanula punctata Lam. var. rubriflora Makino. Somatic embryos (SE) were obtained with greater frequency from petiole explants than from leaf explants when cultured
on Murashige and Skoog (MS) medium supplemented with 2.0 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg L−1 6-benzyladenine (BA). On this medium, a mean number of 19.5 and 31.2 SE were developed per leaf and petiole explants, respectively.
Embryos were induced both light and dark conditions but culturing the explants 2 weeks in the dark followed by 3 weeks under
light resulted in high frequency of embryo formation. Globular embryos germinated best on MS medium supplemented with 0.3%
(w/v) activated charcoal (AC) and 1.0 mg L−1 GA3. The germinated plantlets grew further on MS medium containing 0.3% AC. Plantlets were successfully acclimatized in the greenhouse
with 94% survival rate. This is the first report on induction of somatic embryogenesis in this genus and also has implications
for genetic transformation, and mass clonal propagation. 相似文献
6.
Two experiments were performed to determine how application of the cytokinin benzyladenine (BA) influenced flowering in Doritaenopsis and Phalaenopsis orchid clones. In the first experiment, two vegetative orchid clones growing in 15-cm pots were transferred from a 28°C greenhouse
that inhibited flowering to a 23°C greenhouse for flower induction (day 0). A foliar spray (0.2 L m−2) containing BA at 100, 200, or 400 mg L−1 or 25, 50, or 100 mg L−1 each of BA and gibberellins A4 + A7 (BA+GA) was applied on days 0, 7, and 14. Plants treated with BA alone at 200 or 400 mg L−1 had a visible inflorescence 3–9 days earlier and had a mean of 0.7–3.5 more inflorescences and 3–8 more flowers per plant
than nontreated plants. The application of BA+GA had no effect on inflorescence number and total flower number at the rates
tested. In the second experiment, three orchid clones received a single foliar spray of BA at 200 mg L−1 at six time points relative to time of transfer from 29°C to 23°C (−1, 0, +1, +2, +4, or +6 weeks). A separate group of plants
received a BA application at week 0 but was maintained at 29°C. Inflorescence number was greatest in all three orchid clones
when plants were treated with BA 1 week after the temperature transfer. Plants that were sprayed with BA and maintained at
29°C did not initiate inflorescences. The promotion of flowering by the application of BA suggests that cytokinins at least
partially regulate inflorescence initiation of Doritaenopsis and Phalaenopsis, but its promotion is conditional and BA application cannot completely substitute for an inductive low temperature. 相似文献
7.
Meiru Li Hongqing Li Xiaoying Hu Xiaoping Pan Guojiang Wu 《Plant Cell, Tissue and Organ Culture》2010,102(3):321-327
Zoysia tenuifolia Willd. ex Trin. is one of the most popularly cultivated turfgrass. This is the first report of successful plant regeneration
and genetic transformation protocols for Z. tenuifolia using Agrobacterium tumefaciens. Initial calli was induced from stem nodes incubated on a Murashige and Skoog (1962) (MS) medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 mg l−1 6-benzyladenine (BA), with a frequency of 53%. Compact calli were selected and subcultured monthly on the fresh medium. Sixty-nine
percent of the calli could be induced to regenerate plantlets when the calli incubated on a MS medium supplemented with 0.2 mg l−1 BA under darkness. For genetic transformation, calli were incubated with A. tumefaciens strain EHA105 harboring the binary vector pCAMBIA 1301 which contains the hpt gene as a selectable marker for hygromycin resistance and an intron-containing β-glucuronidase gene (gus-int) as a reporter gene. Following co-cultivation, about 12% of the callus explants produced hygromycin resistant calli on
MS medium supplemented with 2 mg l−1 2,4-D, 1 mg l−1 BA, 50 mg l−1 hygromycin, 500 mg l−1 cefotaxime after 8 weeks. Shoots were regenerated following transfer of the resistant calli to shoot induction medium containing
0.2 mg l−1 BA, 50 mg l−1 hygromycin, and 250 mg l−1 cefotaxime, and about 46% of the resistant calli differentiated into shoots. Finally, all the resistant shoots were rooted
on 1/2 MS media supplemented with 50 mg l−1 hygromycin, 250 mg l−1 cefotaxime. The transgenic nature of the transformants was demonstrated by the detection of β-glucuronidase activity in the primary transformants and by PCR and Southern hybridization analysis. About 5% of the total
inoculated callus explants produced transgenic plants after approximately 5 months. The procedure described will be useful
for both, the introduction of desired genes into Z. tenuifolia and the molecular analysis of gene function. 相似文献
8.
Hai-Nan Su Bin-Bin Xie Xiu-Lan Chen Jin-Xia Wang Xi-Ying Zhang Bai-Cheng Zhou Yu-Zhong Zhang 《Journal of applied phycology》2010,22(1):65-70
Allophycocyanin (APC) is a minor component of phycobiliproteins in cyanobacteria and red algae. This paper describes a simple
and inexpensive extracting method for isolating APC from Spirulina (Arthrospira) platensis with high efficiency. The crude phycobiliprotein extract was pretreated by ammonium sulfate fractionation. Then, by adding
hydroxylapatite into crude phycobiliprotein extract dissolved in 20 mM phosphate buffer (pH 7.0), APC was selectively adsorbed
by hydroxylapatite but C-phycocyanin (C-PC) was not. The hydroxylapatite was collected and APC was extracted from the crude
phycobiliprotein extract. Then, the enriched APC was washed off from the hydroxylapatite using 100 mM phosphate buffer (pH 7.0).
In this simple extracting method it was easy to remove C-PC and isolate APC in large amounts. The absorbance ratio A
650/A
280 of extracted APC reached 2.0. The recovery yield was 70%, representing 4.61 mg · g−1 wet weight. The extracted APC could be further purified by a simple anion-exchange chromatography with a pH gradient from
5.6 to 4.0. The absorbance ratio A
650/A
280 of the purified APC reached 5.0, and the overall recovery yield was 43%, representing 2.83 mg · g−1 wet weight. Its purity was confirmed by native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate-PAGE. 相似文献
9.
Bilal Haider Abbasi Murad Khan Bin Guo Saleem Ahmed Bokhari Mir Ajab Khan 《Plant Cell, Tissue and Organ Culture》2011,105(3):337-344
The regeneration potential and antioxidative enzyme activities of economically important Brassica rapa var. turnip were evaluated. Calli were induced from leaf explants of seed-derived plantlets on Murashige and Skoog (MS) medium incorporated
with different concentrations of various plant growth regulators (PGRs). The highest leaf explant response (83%) was recorded
for 2.0 mg l−1 benzyladenine (BA) and 1.0 mg l−1 α-naphthaleneacetic acid (NAA). Subsequent subculturing of callus after 3 weeks of culture, on medium with similar compositions
of PGRs, induced shoot organogenesis. The highest shoot induction response (83%) was recorded for 5.0 mg l−1 BA after 5 weeks of transfer. However, 7.8 shoots/explant were recorded for 2.0 mg l−1 BA. The transferring of shoots to elongation medium resulted in 5.1-cm-long shoots on 10 mg l−1 of gibberellic acid (GA3). Rooted plantlets were obtained on MS medium containing different concentrations of indole butyric acid (IBA). The determination
of activities of antioxidative enzymes (superoxide dismutase [SOD], ascorbate peroxidase [APX], catalase [CAT], glutathione
peroxidase [GPX], and peroxidase [POD]) revealed involvement of these enzymes in callus formation and differentiation. All
of the activities were interlinked with each other and played significant roles in the scavenging of toxic free radicals.
This study will help in the advancement of a regeneration protocol for B. rapa var. turnip and the understanding of the functions of antioxidative enzymes in plant differentiation. 相似文献
10.
A. Karthikeyan J. Shilpha S. Karutha Pandian M. Ramesh 《Plant Cell, Tissue and Organ Culture》2012,109(1):153-165
A reproducible and highly efficient protocol for Agrobacterium tumefaciens-mediated transformation of indica rice (Oryza sativa L. subsp. indica cv. ADT 43) was established. Prior to transformation, embryogenic callus were induced from mature seeds incubated on Linsmaier
and Skoog (LS) medium supplemented with 2.5 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg l−1 thiamine-HCl. Callus, intact mature seeds, and other in vitro derived explants (leaf bases, leaf blades, coleoptiles, and
root-tips) were immersed in a bacterial suspension culture of A. tumefaciens strain EHA 105, OD600 of 0.8, and co-cultivated on LS medium for 2 days in the dark at 25 ± 2°C. Based on GUS expression
analysis, 10 min incubation time of explants on a co-cultivation medium containing 100 μM acetosyringone was optimum. Following
β-glucuronidase (GUS) assay and polymerase chain reaction (PCR) analysis, transformants were identified. Stable integration
of the transgene was confirmed in four putatively transformed T0 plants by Southern blot analysis. The copy number of the transgene in these lines, one to two, was then determined. Among
the observations made, necrosis of co-cultivated explants was a problem, as well as sensitivity of callus to Agrobacterium infection. Levels of necrosis could be minimized following co-cultivation of explants in a medium consisting of 30% LS and
containing 10 g l−1 (14), polyvinyl pyrrolidone, 10% coconut water, and 250 mg l−1 timentin (15:1). This latter medium also increased the final transformation efficiency to 15.33%. 相似文献
11.
12.
B. Kozomara B. Vinterhalter Lj. Radojević D. Vinterhalter 《In vitro cellular & developmental biology. Plant》2008,44(2):142-147
A procedure for the micropropagation of Chimonanthus praecox (L) Link, wintersweet, has been developed using buds from adult trees excised in spring. Shoot cultures established on Murashige
and Skoog (1962) medium supplemented with 0.5 mg l−1 6-benzyladenine (BAP) and 0.1 mg l−1 indole-3-butyric acid (IBA) were difficult to maintain in vitro through extended periods of time due to browning of the medium, shoot and leaf necrosis, and hyperhydricity. A treatment
combining the use of 0.1% w/v activated charcoal and addition of a double phase agar-solidified/liquid medium improved propagation, enabling a successful
in vitro propagation scheme to be developed. Optimal shoot multiplication occurred on medium containing 0.5 mg l−1 BAP, and rooting on medium with 2.0 mg l−1 IBA for 7 d, followed by transfer to hormone-free medium. Rooted plantlets were easily acclimated in a glasshouse and replanted
and cultured outdoors. 相似文献
13.
14.
Elena Palomo-Ríos Araceli Barceló-Muñoz José A. Mercado Fernando Pliego-Alfaro 《Plant Cell, Tissue and Organ Culture》2012,109(2):201-211
Key factors influencing the efficiency of transformation of embryogenic cultures, induced from immature zygotic embryos, of
avocado cv. ‘Duke 7’ were evaluated. Initially, the sensitivity of somatic embryos to the antibiotics kanamycin, used for
selection, carbenicillin, cefotaxime and timentin, all used for elimination of Agrobacterium cells, were evaluated. Isolated globular somatic embryos were more sensitive to kanamycin than embryogenic masses, and 25 mg l−1 kanamycin completely restricted callus proliferation. Cefotaxime at 500 mg l−1 partially inhibited proliferation of embryogenic cultures, while both carbenicillin and timentin did not affect callus growth.
For genetic transformation, somatic embryos were infected with A. tumefaciens containing the pBINUbiGUSint plasmid. After 2 days, the embryos were transferred to selection medium supplemented with 50 mg l−1 kanamycin and 250 mg l−1 timentin for 2 months. Then, kanamycin level was increased to 100 mg l−1 for two additional months. The A. tumefaciens strain AGL1 yielded higher transformation rates, 6%, than EHA105 or LBA4404, 1.2%. The percentage of kanamycin resistant
calli obtained was significantly influenced by the embryogenic line used as source of explants. Genetic transformation was
confirmed by PCR and Southern blot analysis. A significant improvement in the germination rate was obtained when transgenic
embryos were cultured in liquid MS medium with 4.44 μM BA and 2.89 μM GA3 for 3 days in a roller drum and later transferred to the same medium gelled with 7 g l−1 agar. Plants from five independent transgenic lines were acclimated and grown in the greenhouse, being phenotipically similar
to control plants. 相似文献
15.
Meiru Li Hongqing Li Xiaoying Hu Xiaoping Pan Guojiang Wu 《Plant Cell, Tissue and Organ Culture》2011,106(3):363-371
Saussurea involucrata is a valuable traditional Chinese medicinal herb. This is the first report of a successful genetic transformation protocol
for S. involucrata using Agrobacterium tumefaciens. Leaf explants were incubated with A. tumefaciens strain EHA105 harboring the binary vector pCAMBIA 1301, which contains the hpt gene as a selectable marker for hygromycin resistance and an intron-containing β-glucuronidase gene as a reporter gene. Following
co-cultivation, about 23.7% of the explants produced hygromycin-resistant calli on MS basal medium (Murashige and Skoog in
Physiol Plant 15: 473–497, 1962) supplemented with 1 mg l−1 benzyladenine (BA), 0.1 mg l−1 α-naphthaleneacetic acid (NAA), 0.1 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D), 20 mg l−1 hygromycin, and 500 mg l−1 cefotaxime. Shoots were regenerated following transfer of the resistant calli to shoot induction medium containing 1.5 mg l−1 BA, 0.1 mg l−1 NAA, 0.25 mg l−1 gibberellic acid (GA3), 20 mg l−1 hygromycin, and 250 mg l−1 cefotaxime, and about 67.5% of the resistant calli differentiated into shoots. Finally, 80% of the hygromycin-resistant shoots
rooted on MS media supplemented with 0.2 mg l−1 NAA, 20 mg l−1 hygromycin, and 250 mg l−1 cefotaxime. The transgenic nature of the transformants was demonstrated by detection of β-glucuronidase activity in the primary
transformants and by Southern blot hybridization analysis. About 16% of the total inoculated leaf explants produced transgenic
plants after approximately 5 months. Using this optimized transformation system, a rice ortholog of the Arabidopsis FLOWERING LOCUS T gene, Hd3a, was transferred into S. involucrata. Introduction of this gene caused an early-flowering phenotype in S. involucrata. 相似文献
16.
Saba Ambreen Memon Xilin Hou Bo Zhu Joseph N. Wolukau 《Acta Physiologiae Plantarum》2009,31(6):1191-1196
The objective of the present work was selection of cultivar and suitable medium for regenerating shoots from leaf segments
of non-heading Chinese cabbage. We evaluated six types of supplemented media with 2.0, 5.0 and 10.0 mg l−1 6-BA; 1.0 and 2.0 mg l−1 TDZ; 0.1, 0.3, 0.5, 0.8 and 1.0 mg l−1NAA; 3.0, 5.0 and 7.5 mg l−1AgNO3; 0.01 mg l−1 2–4, D and 4.0 mg l−1 KT for shoot regeneration and six cultivars “Sanchidaye”, “Liuchuandasuomian”, “Qingyou 4”, “Liangbaiye”, “AiKang 5” and
“Hanxiao F3”, furthermore for root formation three types of supplemented media with 0.2, 0.3, 0.5 mg l−1 NAA, and for survival rate two types of base media: turf + vermiculite + manure (1:2:0.2) and soil + vermiculite (1:2). Culturing
leaf segments on MS medium supplemented with 2 mg l−1 TDZ; 0.5 mg l−1 NAA and 7.5 mg l−1 AgNO3 gave the highest number of shoots per leaf segment (66) while roots were best formed on the medium supplemented with 0.2 mg l−1 NAA. Survival rate was highest (61.6%) in the turf: vermiculite: manure (1:2:0.2) medium. The highest percentage of responding
leaf segments, number of shoots per leaf segment, rooting percentage and survival rate were observed in “Liuchuandasuomian”.
The plantlets were transferred to the soil and grown into mature plants in pots. These results could be used for preliminary
selections of cultivars to transfer disease resistance (Bt) gene through agrobacterium in non-heading Chinese cabbage. 相似文献
17.
Teodora Janković Branka Vinterhalter Dijana Krstić-Milošević Radomirka Nikolić Dragan Vinterhalter Slobodan Milosavljević 《Acta Physiologiae Plantarum》2011,33(4):1515-1520
Shoot cultures of Gentianella bulgarica established from seedling epicotyls were maintained on MS medium supplemented with BA 0.2 mg l−1 + NAA 0.1 mg l−1. Cultures were prone to precocious flowering requiring the use of small shoot buds for multiplication purposes. The contents
of three xanthone compounds identified as DGL, BGL, and DMB, in different plant material were determined by HPLC. The analysis
revealed that the production of xanthones was affected by different concentrations of BA in medium. Shoot cultures grown at
higher BA concentrations contained more DGL than material grown in nature. The concentrations of other two xanthones were
lower in shoot cultures than in plants from nature. The radical scavenging activity of plant extracts and xanthones was investigated
by DPPH test. Samples from plants grown in nature showed the highest activity (IC50 = 0.26 mg ml−1), while the extracts of shoot cultures grown in media with higher concentrations of BA showed moderate activities (IC50 from 1.6 to 4.4 mg ml−1). 相似文献
18.
Dioscorea fordii Prain et Burk., a member of the family Dioscoreaceae, is an important tuberous food in China owing to its edible and medicinal
functions. However, the lack of healthy planting material has restricted its production. The present study was an attempt
to develop a protocol for in vitro propagation of D. fordii. In an initial two by two (22) factorial experiment, the effects of culture system and activated charcoal have been observed for axillary shoot proliferation
and tuberization of in vitro plantlets. Shoot length, frequency of proliferation, fresh weight and dry weight of shoots, frequency
of tuberization and mean number of tubers per plantlet (NTPs) were significantly (P ≤ 0.05) greater in liquid medium compared to semi-solid media. Secondly, an orthogonal experimental design [L9 (34)] was used to investigate the effects of the ratio of naphthalene acetic acid (NAA) to 6-benzyladenine (BA) (NAA/BA), paclobutrazol,
methyl jasmonate and sucrose concentration on tuberization. Sucrose concentration had the record effect on frequency of tuberization,
NTPs and frequency of proliferation. The preferred medium for axillary shoot proliferation and tuberization of D. fordii found to be MS basal medium (Murashige and Skoog in Physiol Plant 15:473–479, 1962) supplemented with 1.0 mg l−1 BA, 0.1 mg l−1 NAA, 30 g l−1 sucrose and 1.5 g l−1 AC in liquid culture. 相似文献
19.
Elif Aylin Ozudogru Ergun Kaya Emrah Kirdok Saliha Issever-Ozturk 《In vitro cellular & developmental biology. Plant》2011,47(2):309-320
An efficient in vitro propagation protocol, applicable both to young and mature explants of two Thymus spp., results in genetically stable plantlets. In vitro-grown shoot tips of Thymus vulgaris L. were exposed to cytokinins (6-benzyladenine, kinetin, and thidiazuron) alone or in combination with auxins, gibberellic
acid (GA3) and/or silver nitrate in order to optimize in vitro shoot proliferation. Optimum shoot proliferation (97% regeneration rate, with 8.6 shoots produced per explant) was obtained
when semi-solid Murashige and Skoog (MS) medium was supplemented with 1 mg L−1 kinetin and 0.3 mg L−1 GA3. Rooting of the shoots was easily obtained on semi-solid MS medium that was either hormone-free or supplemented with auxins.
However, the best root apparatus (92.5% rooting rate, with 19 adventitious roots per shoot) developed on MS medium supplemented
with 0.05 mg L−1 2,4-dichlorophenoxyacetic acid. Genetic stability was confirmed in the in vitro-germinated mother plant as well as the shoots that underwent two, four, six, eight, or ten cycles of in vitro subculturing by random amplified polymorphic DNA (RAPD) analysis. When applied to the micropropagation of mature shoot tips
of T. longicaulis C. Presl subsp. longicaulis var. subisophyllus (Borbás) Jalas, the optimized in vitro propagation protocol resulted in a 97.5% shoot regeneration rate, with five shoots formed per explant, and 100% rooting.
Rooted plantlets of both species were transferred to 250-mL plastic pots and successfully acclimatized by gradually reducing
the relative humidity. 相似文献
20.
Filtrates from crushed Moringa oleifera seeds were tested for their effects on growth and Photosystem II efficiency of the common bloom-forming cyanobacterium Microcystis aeruginosa. M. aeruginosa populations exhibited good growth in controls and treatments with 4- and 8-mg crushed Moringa seeds per liter, having similar growth rates of 0.50 (±0.01) per day. In exposures of 20- to 160-mg crushed Moringa seeds L−1, growth rates were negative and on average −0.23 (±0.05) .day−1. Presumably, in the higher doses of 20- to 160-mg crushed seeds per liter, the cyanobacteria died, which was supported by
a rapid drop in the Photosystem II efficiency (ΦPSII), while the ΦPSII was high and unaffected in 0, 4, and 8 mg L−1. High-density populations of M. aeruginosa (chlorophyll-a concentrations of ∼270 μg L−1) were reduced to very low levels within 2 weeks of exposure to ≥80-mg crushed seeds per liter. At the highest dosage of 160 mg L−1, the ΦPSII dropped to zero rapidly and remained nil during the course of the experiment (14 days). Hence, under laboratory conditions,
a complete wipeout of the bloom could be achieved. This is the first study that yielded evidence for cyanobactericidal activity
of filtrate from crushed Moringa seeds, suggesting that Moringa seed extracts might have a potential as an effect-oriented measure lessening cyanobacterial nuisance. 相似文献