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1.
The effect of increasing concentration of polycyclic aromatic hydrocarbon (PAH) fluoranthene (FLT; 0.1, 1 and 5 mg l−1) on the growth, ethylene production and anatomy of stems of 21-day-old pea plants cultivated in vitro in MS medium, with
or without FLT, enriched with 0.1 mg l−1 indole-3-acetic acid (IAA) or with combination of 0.1 mg l−1 IAA + 0.1 mg l−1 N6-benzyladenine (BA) were investigated. The low concentration of 0.1 mg l−1 FLT, in both IAA- and IAA + BA-treated plants, significantly stimulated the growth of pea callus, while higher concentrations
1 mg l−1 and especially 5 mg l−1 FLT significantly inhibited it. Pea shoots were significantly influenced only after application of 5 mg l−1 FLT in IAA treatment. Significantly increased production of ethylene was found in IAA + BA treatments in all concentrations
of FLT, whereas in IAA treatments in 1 and 5 mg l−1 FLT. The lysigenous aerenchyma formation in the cortex of pea stems significantly increased in all FLT treatments and its
highest proportion was found in plants exposed to 1 mg l−1 FLT. 相似文献
2.
K. Balaraju P. Agastian J. P. Preetamraj S. Arokiyaraj S. Ignacimuthu 《In vitro cellular & developmental biology. Plant》2008,44(5):436-441
This study describes in vitro shoot induction and plant regeneration from a mature apical meristem and nodal explants of the endangered medicinal shrub
Vitex agnus-castus. Multiple shoots were induced directly from the axis of nodal and apical meristem explants on Murashige and Skoog (MS) medium
containing 3% sucrose and different concentrations (1.0, 1.5, 2.0, and 2.5 mg/l) of 6-benzyl aminopurine (BAP) in combination
with Kinetin (Kin) and α-naphthalene acetic acid (NAA), both at 0.1 mg/l. BAP and Kinetin were used as supplements to MS basal
medium, either individually or in combination with auxins. The optimal concentration of BAP for inducing bud break was found
to be 2.0 mg/l when Kinetin was at 0.1 mg/l. Regeneration frequency was highest for both apical meristem and nodal explants
(94.5% and 90.3%, respectively) when explants were cultured on MS medium supplemented with BAP (2.0 mg/l) and Kin (0.1 mg/l).
A maximum of 7.7 ± 0.4 and 6.7 ± 0.2 shoots were obtained per explant for apical meristem and nodal explants, respectively.
Regenerated shoots, transferred to MS medium supplemented with either 1.0 or 1.5 mg/l BAP combined with 0.1 mg/l GA3, showed maximum elongation of 6.7 ± 0.4 and 6.0 ± 1.3 cm in apical meristem and nodal explants, respectively. In vitro regenerated shoots transferred to half-strength MS medium supplemented with 0.1 mg/l IBA induced 90.4% of the shoots to form
roots after 30–35 d of culture. Up to 80% of the regenerated shoots were successfully established in soil in the greenhouse. 相似文献
3.
Lingyan Hu Haiyan Chen Guangqun Zhang Zihao Yu Kai Yan Fangdong Zhan Yongmei He 《Phyton》2022,91(9):1933-1944
Indoleacetic acid (IAA) is an important regulator that plays a crucial role in plant growth and responses to abiotic
stresses. In the present study, a sand cultivation experiment was carried out to investigate the effects of IAA at
different concentrations (0, 0.01, 0.1, 0.5, 1, and 2.5 mmol/L) on maize growth, root morphology, mineral elements (Ca, Mg) and Cd uptake under 20 mg/kg Cd stress. The results showed that 0.01 mmol/L is the optimal
IAA concentration for enhancing the Cd tolerance of maize. Compared with the control treatment, 0.01 mmol/L
IAA promoted maize growth, with significant increases in the height, shoot and root biomass by 34.6%, 25.0%
and 16.3%; altered the root morphology, with increases in root length, root tip number, and root tip density
by 8.9%, 31.4% and 20.7%, respectively; and enhanced the mineral element uptake of maize, resulting in signifi-
cant increases in the Ca content in shoots and roots by 640.6% and 1036.4% and in the Mg content in shoots by
205.8%, respectively. In addition, 0.01 mmol/L IAA decreased the Cd content and uptake in the shoots by 51.9%
and 39.6%, respectively. Furthermore, the Cd content and uptake exhibited a significant negative correlation with
Ca content in roots and a significantly positive correlation with root morphology, and the Cd content in shoots
was significantly and negatively correlated with root tip number. Thus, 0.01 mmol/L IAA was effective in enhancing the Cd tolerance and plant growth of maize. 相似文献
4.
The 8 days old seedlings of pea (cv. Ilowiecki) and maize (cv. Alma F1) were subjected to differentiated aeration conditions (control — with pore water tension about 15 kPa and flooded
treatment) for 12 days at three soil temperatures (7, 15 and 25 °C). The shoots were grown at 25 °C while the soil temperature
was differentiated by keeping the cylinders with the soil in thermostated water bath of the appropriate temperature.
Lowering the root temperature with respect to the shoot temperature caused under control (oxic) conditions a decrease of the
root penetration depth, their mass and porosity as well as a decrease of shoot height, their mass and chlorophyll content;
the changes being more pronounced in maize as compared to the pea plants. Flooding the soil diminished the effect of temperature
on the investigated parameters; the temperature effect remaining significant only in the case of shoot biomass and root porosity
of pea plants. Root porosity of pea plants ranged from 2 to 4 % and that of maize plants — from 4 to 6 % of the root volume.
Flooding the soil caused an increase in the root porosity of the pea plants in the entire temperature range and in maize roots
at lower temperatures by about 1 % of the root volume. Flooding the soil caused a decrease of root mass and penetration depth
as well as a decrease of plant height, biomass and leaf chlorophyll content. 相似文献
5.
Diego Muñoz-Concha Michael R. Davey 《In vitro cellular & developmental biology. Plant》2011,47(1):170-175
The endangered tree Gomortega keule remains only in small, isolated populations surrounded by timber plantations in the biodiversity hotspot of central Chile.
This species, belonging to the monotypic family Gomortegaceae, produces edible fruit and high-quality wood, but its difficult
propagation makes conservation essential. The percentage of seed germination is less than 40%, germination time exceeds 12 mo,
and cuttings fail to root. These difficulties have stimulated efforts to explore in vitro approaches for propagation. Cultures were established from zygotic embryos; the optimum culture conditions for shoot proliferation
were semi-solid Woody Plant Medium (WPM) with 20 g/l sucrose, 0.1 mg/l α-naphthaleneacetic acid and 1.0 mg/l 6-benzylaminopurine,
at 18°C. Explants required about 12 mo in culture before stabilized growth resulted in consistent shoot production. Regenerated
shoots excised from parental explants developed a normal morphology 1 mo after transfer to WPM with 2.0 g/l of activated charcoal,
and lacking plant growth regulators. These normal shoots were rooted with a treatment of 7 d on WPM without activated charcoal,
but containing 20 mg/l indole-3-butyric acid, followed by return to the same medium with 2.0 g/l activated charcoal, without
growth regulators, for 1 mo. Regenerated plants were transferred to compost and covered with transparent plastic sleeves.
The latter were opened gradually to decrease humidity and to establish plants under glasshouse conditions. There is an urgent
requirement to extend this protocol to material collected from diverse sites and to introduce micropropagated specimens into
the wild and living plant repositories to conserve this endangered species. 相似文献
6.
Abstract A protocol of protoplast isolation from Egyptian varieties of pea and bean is reported. Protoplast cultures were established from apical shoots of pea (Pisum sativum) and suspension cultures of bean (Phaseolus vulgaris). To isolate protoplasts of pea, apical shoot tissues were digested for 10 h using enzyme solution containing 1% pectinase, 0.5% cellulase, 0.5% hemicellulase, 10% mannitol and 0.1% CaCl2-2H2O. For protoplast isolation from suspension culture of bean, collected cells were incubated for 6 h in digestion solution containing 0.5% pectinase, 0.25% of each of cellulase and hemicellulase, 10% mannitol and 0.1% CaCl2-2H2O. Purified protoplasts were cultured in liquid culture medium. Microcalli were obtained after 30 days of culture. Calli colonies with a diameter of about 5 mm were developed after one month of culturing on solid B5 medium containing 2% sucrose, 2 g/l casein hydrolysate, 0.7% agar and supplemented with either 1 mg/l of each 2,4-D and kin in case of pea or 2 mg/l 2,4-D+0.5 mg/l kin in case of bean. Protoplast derived callus of pea was successfully differentiated into shoot and root, and highest frequency of shoot organogenesis was recorded on medium containing 0.5 mg/l NAA+2 mg/l BA. Protoplast derived callus of bean, on the other hand, gave rise to a high frequency of root formation when cultured on medium containing 1 mg/l NAA, but attempts to regenerate shoots from this callus was unsuccessfull. 相似文献
7.
Marie Kummerová Lucie Váňová Helena Fišerová Marek Klemš Štěpán Zezulka Jana Krulová 《Plant Growth Regulation》2010,61(2):161-174
Environmental contaminants like polycyclic aromatic hydrocarbons can influence many biochemical and physiological processes
in plants. The effect of 0.1, 1 and 5 mg l−1 of fluoranthene (FLT) in combination with indole-3-acetic acid (IAA, 0.1 mg l−1) or a combination of IAA and N6-benzyladenine (BA, both 0.1 mg l−1) on the growth and production of ethylene, ethane and CO2 in Pisum sativum L. cultivated for 21 days in vitro was investigated. In 21 days old plants also net photosynthesis rate, content of FLT and
cytokinins were evaluated. FLT 5 mg l−1 significantly inhibited the growth of pea after 21 days in both IAA and IAA + BA treatments, increased production of ethylene
(by 11% in IAA and 14% in IAA + BA treatments, respectively) and ethane (by 28 and 18%) and decreased production of CO2 (by 23 and 29%). The net photosynthesis rate decreased in response to FLT concentration by up to 51% under saturating irradiation
(600–1,200 μmol m−2 s−1), as found in IAA + BA + FLT 5 mg l−1 treatment. The content of FLT in pea plant shoots well correlated with increasing FLT treatment in both IAA and IAA + BA
medium. The content of cytokinins in pea shoots changed in response to FLT treatment. FLT 5 mg l−1 caused a rise in level of trans-zeatin (by 16% in IAA and 9% in IAA + BA treatments, respectively), dihydrozeatin riboside (by 27 and 50%), benzyladenine
(by 3 and 80%), benzyladenine riboside (by 44 and 17%) and meta-topolin riboside (by 139 and 214%), no change in isopentenyladenine level and a decrease in meta-topolin level (by 33% in IAA and 36% in IAA + BA treatments, respectively). Cultivation of plants in vitro allowed not only
to assess their growth, photosynthetic activity and the level of cytokinins, but also to extend the knowledge about the effect
of PAHs on production of gaseous stress indicators like ethylene, ethane and CO2. Recorded changes in all studied parameters show, that persistent organic pollutants like PAHs can negatively influence plant
growth and development. 相似文献
8.
Ill-Whan Sul Schuyler S. Korban 《In vitro cellular & developmental biology. Plant》1998,34(4):300-302
Summary Leaves ofPhlox paniculata L. were bombarded with BA-coated gold microprojectiles with the Biolistic PDS/1000-He gene gun. Increasing the concentration
of BA from 0.01 to 0.1 mg/μl increased the mean number of adventitious shoots from 7 to 16 shoots per leaf. Bombardment of
cotyledons ofPinus pinea L. (Italian stone pine) with BA-coated gold particles significantly reduced the frequency of shoot organogenesis by about
40%. However, induced shoot regenerants from bombarded explants of bothP. paniculata andP. pinea were longer (>1 cm) than those derived from control explants after 3 and 5 wk following bombardment, respectively. 相似文献
9.
M. Koné E. M. Patat-Ochatt C. Conreux R. S. Sangwan S. J. Ochatt 《Plant Cell, Tissue and Organ Culture》2007,88(1):61-75
The morphogenetic competence of Bambara groundnut was assessed for different landraces, explant sources and media compositions.
With cotyledon explants, the best callusing occurred on a medium containing 3 mg/l BAP + 0.5 mg/l NAA, while roots were produced
with 3–5 mg/l BAP + 0.5 mg/l NAA. Shoots regenerated (∼6%) from cotyledons on media with BAP alone (3–5 mg/l) or combined
with 0.01–0.1 mg/l NAA. Flowers were regenerated on 5 mg/l BAP + 0.5 mg/l NAA, without any intervening callus phase. With
epicotyls, the highest callusing was on 3 mg/l BAP + 0.5 mg/l NAA, and shoots regenerated (15–20%) on 3 mg/l BAP alone or
with NAA at concentrations that depended on the landrace studied. Regenerated shoots rooted on hormone-free medium, and plants
transferred to the greenhouse were all morphologically normal and fertile. Flow cytometry showed that most regenerants were
diploid and in addition permitted to distinguish between landraces according to their relative nuclear DNA content. This is
the first report on de novo regeneration in vitro of Bambara groundnut, an important yet neglected legume crop. 相似文献
10.
Accumulation and transport of nickel in relation to organic acids in ryegrass and maize grown with different nickel levels 总被引:6,自引:0,他引:6
Difference in Ni tolerance/accumulation in plant genotypes might be used to identify or develop plants for remediation of high Ni soils. Ryegrass was shown to be more sensitive to Ni toxicity and accumulated much more Ni in shoots than maize. The objectives of this study were to examine the relationship of organic acids to Ni accumulation and xylem transport of Ni in ryegrass (Lolium perenne L.) and maize (Zea mays L.). The results showed that accumulation of Ni in shoots was 5 to 7 fold higher in ryegrass than in maize grown at 20 to 80 µM Ni, whereas Ni concentration in ryegrass roots was only 1 to 2 fold higher at 0.1 to 40 µM Ni and 1.5-fold lower at 80 µM Ni than that of maize roots. Xylem transport rates of Ni increased with increasing Ni supply for both species, and were about 2 to 7 times higher in ryegrass than in maize. Shoot concentrations of citric, malic, oxalic and cis-aconitic acids increased at Ni levels above 20 µM, and were about 2 to 6 times higher in ryegrass than in maize. Whereas, maize roots accumulated greater amount of malic, oxalic, and cis-aconitic acids than ryegrass roots, especially at Ni levels of 40-80 µM. The rate of Ni exudation by roots in the two species was significantly correlated with root Ni concentrations. It could be concluded that high Ni accumulation in shoots was closely related to high xylem transport rates of Ni and that the accumulation of organic acids, citric and malic acid in particular. A high root exudate rate of Ni and the enhanced accumulation of organic acids, malic acid in particular, in roots might be among the important factors which are associated with the tolerance of crops to toxic Ni levels. 相似文献
11.
Subramanian KS Virgine Tenshia JS Jayalakshmi K Ramachandran V 《Indian journal of microbiology》2011,51(1):37-43
A greenhouse experiment was conducted to examine the changes in antioxidant enzyme activities of arbuscular mycorrhizal (AM)
fungus Glomus intraradices Schenck and Smith inoculated (M+) and non-inoculated (M−) maize (Zea mays L.) plants (variety COHM5) under varying levels of zinc (0, 1.25, 2.5, 3.75 and 5.0 mg kg−1). Roots and shoots sampled at 45 days after sowing (DAS) were estimated for its antioxidant enzymes (superoxide dismutase,
peroxidase) IAA oxidase, polyphenol oxidase, acid phosphatase and nutritional status especially P and Zn concentrations. Mycorrhizal
inoculation significantly (P ≤ 0.01) increased all the four antioxidant enzymes in both roots and shoots at 45 DAS regardless of Zn levels. All enzyme
activities except SOD increased progressively with increasing levels of Zn under M+ and M− conditions. The SOD activity got
decreased in roots and shoots at 2.5 and 3.75 mg Zn kg−1. Acid phosphatase activity in M+ roots and shoots were higher in all levels of Zn but the values decreased with increasing
levels of Zn particularly in roots. Mycorrhizal fungus inoculated plants had higher P and Zn concentrations in both stages
in comparison to non-inoculated plants. Our overall data suggest that mycorrhizal symbiosis plays a vital role in enhancing
activities of antioxidant enzymes and nutritional status that enables the host plant to sustain zinc deficient conditions. 相似文献
12.
Diego Muñoz-Concha Sean Mayes Gracia Ribas Michael R. Davey 《Plant Cell, Tissue and Organ Culture》2012,109(1):123-130
The endangered Chilean tree Gomortega keule (Mol.) Baillon produces edible fruit, making it a potential crop. However, its cultivation from seed or cuttings is extremely
difficult. This paper reports the induction of somatic embryogenesis and the initiation of liquid cultures in this species.
Callus was induced from zygotic embryos and field-collected shoots. Somatic embryogenesis on zygotic embryos occurred at a
low frequency. Induction of somatic embryogenesis was accomplished on micropropagated shoots after 6.5 months on semi-solid
Murashige and Skoog (MS) medium with 30 g/l sucrose, 1.0 mg/l 2,4-dichlorophenoxyacetic acid and 1.0 mg/l 6-(γ,γ-dimethylallylamino)
purine (2iP). Liquid cultures of compact callus and small aggregates were obtained and showed optimum proliferation in MS
medium with 20 g/l sucrose, 0.01 mg/l α-naphthaleneacetic acid and 0.1 mg/l 2iP. The proliferation of friable embryogenic
callus was observed in liquid medium and will allow the propagation of selected genotypes of this tree on a large scale. Genetic
variation in two embryogenic genotypes cultured in vitro was not detected in an assessment using microsatellites; this approach
is suitable for tracing genotypes. 相似文献
13.
Eugenio Pérez Molphe Balch Martha E. Pérez Reyes Enrique Villalobos Amador Ernestina Meza Rangel Leticia del Rocío Morones Ruiz Hugo J. Lizalde Viramontes 《In vitro cellular & developmental biology. Plant》1998,34(2):131-135
Summary We have developed micropropagation systems for 21 species of Mexican cacti using explants from seedlings germinatedin vitro or shoot segments of juvenile 2–3-yr-old greenhouse plants. The species propagated belong to the generaAstrophytum, Cephalocereus, Coryphantha, Echinocactus, Echinocereus, Echinofossulocactus, Ferocactus, Mammillaria, Nyctocereus, andStenocactus. Multiple shoot formation from areoles was achieved in Murashige and Skoog (MS) medium supplemented with either 1 or 2 mg
N6-benzyladenine (BA) per 1 (4.44 or 8.87 μM) or BA at 1 or 2 mg/l plus naphthaleneacetic acid at 0.1 or 1 mg/l (0.54 or 5.37 μM). The requirements of growth regulators for optimal shoot proliferation, the velocity of the response, and the number of
buds produced by explant were different among the genera and species studied. Rooting of the shoots generatedin vitro was achieved in MS medium supplemented with indoleacetic acid at 0.5–1 mg/l (2.85–5.71 μM) or indolebutyric acid at 0.5–1 mg/l (2.46–4.90 μM). Finally, 70–95% of the rooted plants transferred to potting medium survived. 相似文献
14.
The influence of increasing concentrations (0.1, 1.0 and 5.0 mg l−1) of fluoranthene (FLT) on growth, endogenous abscisic acid (ABA) level and primary photosynthetic processes in 21-day-old
pea plants (Pisum sativum L.) in vitro was investigated. Murashige and Skoog’s (MS) medium, with or without FLT, was enriched with indole-3-acetic
acid (IAA; 0.1 mg l−1) or a combination of IAA (0.1 mg l−1) plus N6-benzyladenine (BA; 0.1 mg l−1). The level of endogenous ABA significantly increased with increasing FLT concentrations in the presence of both IAA and
IAA plus BA. An increased level of endogenous ABA was observed in plants treated with IAA alone. The growth of shoot, callus
and the content of photosynthetic pigments (chlorophyll a and b, carotenoids), in both IAA- and IAA plus BA-treated plants, were significantly stimulated by FLT at its lowest concentration
(0.1 mg l−1) assayed in this study. However, FLT at higher concentrations (1.0 and 5.0 mg l−1) significantly inhibited all these parameters. Chlorophyll fluorescence imaging showed that FLT only at the highest concentration
(5.0 mg l−1) in the presence of IAA (0.1 mg l−1) significantly increased F0, but decreased FV/FM and ΦII. 相似文献
15.
Rapid shoot proliferation was established by adventitious shoot formation on internodal segments. Cross sections of the shoot initiation area were observed microscopically and adventitious shoots were studied under the scanning electron microscope. Shoots were directly formed on the epidermis of internodal segments in vitro without callusing, but not on that of nodal segments with axillary buds. The use of media containing 0.01 – 0.1 mg/l 6-benzyladenine or 0.1 mg /l kinetin and culture under 16 h light increased the number of shoots per segment. The shoots thus obtained were rooted on phytohormone-free Woody Plant or Gamborg B5 solid medium, and were then transferred to soil. When potted, these grew well in a greenhouse. The emetic alkaloid content of adventitious shoots and regenerated plants was determined by HPLC. In vitro shoots cultured in Woody Plant liquid medium supplemented with 0.01 – 0.1 mg/l 6-benzyladenine contained 0.04 – 0.07 % dry wt. emetine and 0.4 – 0.5 % dry wt. cephaeline. One-year old regenerated plants cultivated in a greenhouse demonstrated the same alkaloid content (roots contained 0.82 % dry wt. emetine and 2.16 % dry wt. cephaeline) as the parental plant.Abbreviations MS
Murashige — Skoog (Murashige and Skoog 1962)
- 1/2 MS
half strength MS
- B5
Gamborg B5 (Gamborg et al. 1968)]
- WP
woody plant (Lloyd and McCown 1980)
- RC
root culture (Thomas and Davey 1982)
- HF
phytohormone free
- BA
6-benzyladenine
- Kin
kinetin
- SEM
scanning electron microscopy
- RDF
rotating drum fermenter 相似文献
16.
M. S. Brar J. M. Al-Khayri C. E. Shamblin R. W. McNew T. E. Morelock E. J. Anderson 《In vitro cellular & developmental biology. Plant》1997,33(2):114-118
Summary Shoot multiplication was induced in cowpea, cv. Georgia-21, from shoot tip explants. Shoot tips, 5 mm long, were isolated
from in vitro-grown seedlings and cultured on MS medium containing N6-benzyladenine (BA) at 1, 2.5, or 5 mg/liter (4.4, 11.1, or 22.2 μM) or 6-furfurylaminopurine (kinetin) at 1, 2.5, or 5 mg/liter (4.6, 11.6, or 23.2 μM) combined with 2,4-dichlorophenoxyacetic acid (2,4-D) at 0.01, 0.1, or 0.5 mg/liter (0.05, 0.5, or 2.3 μM) or naphthaleneacetic acid (NAA) at 0.01, 0.1, or 0.5 mg/liter (0.05, 0.5, or 2.7 μM). Cultures were maintained at a 12-h photoperiod (40 μmol·m−2·s−1) and 23 ± 2° C. Treatments with BA induced greater shoot proliferation than those with kinetin. The highest number of shoots
was produced on 5 mg (22.2 μM) BA per liter in combination with NAA or 2,4-D at 0.01 mg/liter (0.05 μM). Callus proliferated from the basal ends of shoot pieces in all treatments. The cultures also formed roots in the presence
of kinetin, but not on BA-containing medium. To produce whole plants, the shoots were separated and rooted on 0.1 mg (0.5
μM) NAA per liter. Resulting plants grew normally under greenhouse conditions. Shoot tips provide an excellent explant source
for cowpea micropropagation and can be used for callus induction. 相似文献
17.
Takayuki Hoson Seiichiro Kamisaka Yoshio Masuda Masamichi Yamashita 《Journal of plant research》1992,105(1):53-70
We developed a three-dimensional (3-D) clinostat to simulate a microgravity environment and studied the changes in plant growth processes under this condition. The rate of germination of cress (Lepidium sativum), maize (Zea mays), rice (Oryza sativa), pea (Pisum sativum), or azuki bean (Vigna angularis) was not affected on the clinostat. The clinostat rotation did not influence the growth rate of their roots or shoots, except for a slight promotion of growth in azuki roots and epicotyls. On the contrary, the direction of growth of plant organs clearly changed on the 3-D clinostat. On the surface of the earth, roots grow downward while shoots upward in parallel to the gravity vector. On the 3-D clinostat, roots of cress elongated along the direction of the tip of root primordia after having changed the direction continuously. Rice roots also grew parallel to the direction of the tip of root primordia. On the other hand, roots of maize, pea, and azuki bean grew in a random fashion. The direction of growth of shoots was more controlled even on the 3-D clinostat. In a front view of embryos, shoots grew mostly along the direction of the tip of primordia. In a side view, rice coleoptiles showed an adaxial (toward the caryopsis) while coleoptiles of maize and epicotyls of pea and azuki bean an abaxial curvature. The curvature of shoots became larger with their growth. Such an autotropism may have an important role in regulation of life cycle of higher plants under a microgravity environment. 相似文献
18.
Zn uptake by maize plants may be affected by the presence of arbuscular mycorrhizal fungi (AMF). Collembola often play an important controlling role in the inter-relationship between AMF and host plants. The objective of this experiment was to examine whether the presence of Collembola at different densities (0.4 and 1 individuals g−1 dry soil) and their activity have any effect on Zn uptake by maize through the plant–AMF system. The presence of the AMF (Glomus intraradices) and of the Collembola species Folsomia candida was studied in a laboratory microcosm experiment, applying a Zn exposure level of 250 mg kg−1 dry soil. Biomass and water content of the plants were no different when only AMF or when both AMF and Collembola were present. In the presence of AMF the Zn content of the plant shoots and roots was significantly higher than without AMF. This effect was reduced by Collembola at both low and high density. High densities of Collembola reduced the extent of AMF colonization of the plant roots and hyphal length in the soil, but low densities had no effect on either. The results of this experiment reveal that the F. candida–G. intraradices interaction affects Zn uptake by maize, but the mechanisms are still unknown. 相似文献
19.
Increasing salinity of growth medium induced a reduction in growth and transpiration rate. The concentrations of chlorophylls and carotenoids were increased in most cases in broad bean leaves while in pea plants they remained more or less unchanged with the rise of salinization up to 80mM NaCl. Thereabove a significant decrease in these contents was observed. A stimulation of the net photosynthetic rate of pea was observed at the lowest levels of NaCl but at the highest levels inhibitory effect was recorded. In broad bean all salinization levels inhibited photosynthetic activity, but dark respiration of both plant species was stimulated. The content of Na+ in the roots and shoots of both species increased at increasing salinity. In broad bean, Ca2+ concentration in shoots and K+ and Ca2+ contents of roots increased at increasing salinization, while in pea plants, the content of K+ and Ca2+ was almost unaffected by salinity. Salinity induced an increase in the content of these ions in pea roots. Mg2+ content in shoots and roots of both broad bean and pea decreased at increasing salinity except in roots of pea, where it was generally increased. 相似文献
20.
Plants were regenerated from leaf explants of Centrosema brasilianum cultured in vitro. Callus and buds were produced on Murashige and Skoog medium (MS), 0.8% agar, 0.1 mg/l NAA and 1 mg/l BAP. Regeneration of multiple shoots was achieved by transferring callus onto fresh medium containing 0.01 and 1 mg/l of NAA and BAP, respectively. Shoots formed roots upon transfer to MS with 0.01 mg/l NAA. Plantlets were succesfully transferred to soil. Leaf-derived calli of Centrosema arenarium, C. macrocarpum, C. pascuorum, C. pubescens, and C. virginianum did not produce shoots when cultured in vitro. 相似文献