共查询到20条相似文献,搜索用时 15 毫秒
1.
J. A. Bunce 《Photosynthetica》2008,46(4):517-524
Plants differ in how much the response of net photosynthetic rate (P
N) to temperature (T) changes with the T during leaf development, and also in the biochemical basis of such changes in response. The amount of photosynthetic acclimation
to T and the components of the photosynthetic system involved were compared in Arabidopsis thaliana and Brassica oleracea to determine how well A. thaliana might serve as a model organism to study the process of photosynthetic acclimation to T. Responses of single-leaf gas exchange and chlorophyll fluorescence to CO2 concentration measured over the range of 10–35 °C for both species grown at 15, 21, and 27 °C were used to determine the
T dependencies of maximum rates of carboxylation (VCmax), photosynthetic electron transport (Jmax), triose phosphate utilization rate (TPU), and mesophyll conductance to carbon dioxide (g’m). In A. thaliana, the optimum T of P
N at air concentrations of CO2 was unaffected by this range of growth T, and the T dependencies of VCmax, Jmax, and g’m were also unaffected by growth T. There was no evidence of TPU limitation of P
N in this species over the range of measurement conditions. In contrast, the optimum T of P
N increased with growth T in B. oleracea, and the T dependencies of VCmax, Jmax, and g’m, as well as the T at which TPU limited P
N all varied significantly with growth T. Thus B. oleracea had much a larger capacity to acclimate photosynthetically to moderate T than did A. thaliana. 相似文献
2.
In lichens, ribitol is known as a carbon storage compound, an osmotic agens involved effectively in cell compartments protection
during dehydration of lichen thalli and as a cryoprotective compound. In our study, we investigated the effect of ribitol
on photochemical processes of photosynthesis in foliose lichens [Lasallia pustulata (L.) Mérat., Umbilicaria hirsuta (Sw. ex Westr.) Hoffm.] at low temperature. The effects of three concentrations of ribitol, added externally to thalli segments
on several chlorophyll (Chl) fluorescence parameters, were evaluated. The 72 h exposition to 8, 16, and 26 mM ribitol led
to a concentration-dependent increase in FV/FM, decrease in non-photochemical quenching (NPQ) but no change in quantum yield of photosystem II photochemistry (ΦPSII) values at −5 °C). At higher temperature (0, +5 °C), no effect of ribitol addition on the photosynthetic parameters was apparent. 相似文献
3.
D. Skálová M. Dziechciarková A. Lebeda E. Křístková B. Navrátilová 《Biologia Plantarum》2008,52(4):775-778
Embryo-rescue was used to facilitate interspecific hybridization of Cucumis anguria L. and C. zeyheri Sond. Embryos were excised from developing fruits at one week intervals for six weeks after hand pollination. Medium containing
coconut water was the most suitable for initial germination, and a medium with ascorbic acid was the best for embryo development
and plant recovery. Viable plants were obtained from embryos and these plants showed morphological characteristics different
from both parents. The analysis of the leucine aminopeptidase (LAP) locus revealed three hybrid types, H1.1, H1.2 and H2. 相似文献
4.
In this study, Dendrobium Sonia 17 plantlets were used to induce in vitro flowering. Inflorescences were induced and rooting was inhibited in the half-strength Murashige and Skoog medium containing
20 μM N
6-benzyladenine (BA). The medium with high P and low N contents was effective to induce inflorescences while the medium with
low P and high N contents was only effective to promote forming of shoots. In addition, the induced in vitro inflorescences were able to multiply and maintain without exhibiting a distinctive vegetative phase. Different morphologies
of in vitro flowers such as incomplete flower structures, abnormal and unresupinated in vitro flowers were observed. 相似文献
5.
Gametophores of mosses Mnium undulatum and Polytrichum commune were submerged in distilled water or in calcium chloride solution (0.9 mM Ca2+) to induce hypoxia. The net photosynthetic (PN) and dark respiration rate (RD) were measured in the air containing 300–400 μmol(CO2)·mol−1(air) and 0.21 mol(O2)·mol−1(air). PN of M. undulatum gametophores decreased to 58 % of the control after 1-h submersion in water, whereas to 80 % of the control in P. commune gametophores. A smaller decrease in PN was observed when the gametophores were immersed in CaCl2 solution. In hypoxia, RD in the tested mosses species was a little higher than in the control. 相似文献
6.
A. I. Cordeiro J. F. Sanchez-Sevilla M. C. Alvarez-Tinaut M. C. Gomez-Jimenez 《Biologia Plantarum》2008,52(4):642-647
Eighty seven olive (Olea europaea ssp. sativa L.) cultivar accessions from Portugal were characterized by means of randomly amplified polymorphic DNA (RAPD) markers. Of
the 11 arbitrary 10-mer primers tested a total of 92 polymorphic bands were obtained, representing 87.6 % of the total amplification
products. Twenty nine different genotypes were clearly discriminated. Differences were not found among the amplification profiles
from different individuals of the same cultivar. All the genotypes could be identified by the combination of three primers:
OPR-1, OPK-14 and OPA-1, seven genotype-specific markers being detected. Genetic relationships were estimated by the unweighted
pair-group method with arithmetic averaging (UPGMA). The genetic analysis of the results showed a gradual distance between
the various cultivars, making it difficult to identify well-differentiated phylogenetic groups, although two clusters were
distinguishable with 35 % similarity, in addition to three independent branches with lower similarity: Galega, Tentilheira
and Redondal. The dendrogram reflect some relationships for most of the cultivars according to the use of the fruit and ecological
adaptation. 相似文献
7.
An efficient micropropagation protocol was established for Capsicum chinense Jacq. cv. Umorok, a pungent chilli cultivar. Shoot-tip explants were cultured on Murashige and Skoog (MS) medium containing
cytokinins (22.2–88.8 μM 6-benzylaminopurine, BAP, 23.2–93.0 μM kinetin, Kin, or 22.8–91.2 μM zeatin, Z) alone or in combination
with 5.7 μM indole-3-acetic acid (IAA). Maximum number of shoots were induced on medium containing 91.2 μM Z or 31.1 μM BAP
with 4.7 μM Kin. The separated shoots rooted and elongated on medium containing 2.5 or 4.9 μM indole-3-butyric acid (IBA).
Axillary shoots were induced from in vitro raised plantlets by decapitating them. The axillary shoot-tip explants were used for further multiple shoot buds induction.
A maximum of about 150 plantlets were obtained from a single seedling. Hardened and acclimatized plantlets were successfully
established in the soil. 相似文献
8.
This paper describes multiple shoot regeneration from leaf and nodal segments of a medicinally important herb Centella asiatica L. on Murashige and Skoog’s (MS) medium supplemented with a range of growth regulators. The highest number of multiple shoots
was observed on MS augmented with 3.0 mg dm−3 N6-benzylaminopurine (BAP) and 0.05 mg dm−3 α-naphthaleneacetic acid (NAA). Leaf explant showed maximum percentage of cultures regenerating shoots (81.6 %), with the
highest shoot number (8.3 shoots per explant) and the shoot length (2.1 cm) whereas, nodal explant showed less number of shoots
with callus formation at the base cut end. Successive shoot cultures were established by repeatedly sub-culturing the original
explant on a fresh medium. Rooting of in vitro raised shoots was best induced on half strength MS supplemented with 0.5 mg dm−3 indole-3-butyric acid (IBA) with highest percentage of shoot regenerating roots (76.8 %) with 3–4 roots per shoot. Plantlets
were acclimated in Vermi-compost and eventually established in soil. Contents of chlorophyll, total sugars, reducing sugars and proteins were estimated in
leaf tissue from both in vivo and in vitro raised plants. Chlorophyll content was higher in in vivo plants, whereas other three components were higher in in vitro plants. 相似文献
9.
M. Chandrika Thoyajaksha V. Ravishankar Rai K. Ramachandra Kini 《Biologia Plantarum》2008,52(4):735-739
In the present study, a polymerase chain reaction (PCR)-based method namely inter simple sequence repeat (ISSR) was employed
to assess genetic stability in tissue culture-derived Dictyospermum ovalifolium plantlets. To study genomic stability of micropropagated plants, 14 individuals were randomly tagged among a population of
2500 regenerants and were compared with single donor mother plant. A total of 51 clear and reproducible bands ranging from
200 bp to 2.1 kb were scored corresponding to an average of 3.64 bands per primer. Two of the 51 bands were polymorphic (3.92
%) among 14 individuals, thus indicating the occurrence of low level genomic variation in the micropropagated plants. Cluster
analysis indicates that genetic similarity values were 0.978 which allows classification of the plants to distinct groups.
Further an attempt was made to reintroduce the micropropagated plants into their natural habitat. Over one thousand six hundred
fifty plants were successfully established. 相似文献
10.
The effects of lead were investigated in bean plants (Phaseolus vulgaris L. cv. Zlota Saxa) grown hydroponically in nutrient solution and exposed to Pb(NO3)2 (0.1, 0.5, 1 mM) with or without equimolar concentrations of chelator ethylenediaminetetraacetic acid (EDTA). The roots treated
only with Pb(NO3)2 accumulated up to 25 g(Pb) kg−1(d.m.), during 4-d exposure. However, in bean plants exposed to 0.5 mM Pb + 0.5 mM EDTA or 1 mM Pb + 1 mM EDTA 2.5 times less
Pb was determined. In bean plants treated only with Pb, less than 6 % of total lead accumulated was transported to the aboveground
parts, while in the case of plants grown with Pb + EDTA, around 50 % of total Pb was transported to the shoots. 相似文献
11.
Direct shoot regeneration from leaf explants of <Emphasis Type="Italic">Spilanthes acmella</Emphasis> 总被引:2,自引:0,他引:2
Multiple shoots of Spilanthes acmella Murr. were induced from nodal buds of in vivo and in vitro seedlings on Murashige and Skoog (MS) medium containing 1.0 mg dm−3 6-benzyladenine (BA) and 0.1 mg dm−3 α-naphthalene-acetic acid (NAA). Adventitious shoots were successfully regenerated from the leaf explants derived from the
above mentioned multiple shoots. The efficiency of shoot regeneration was tested in the MS medium containing BA, kinetin,
or 2-isopentenyl adenine in combination with NAA, indole-3-acetic acid (IAA), or indole-3-butyric acid (IBA) and gibberellic
acid. Maximum number of shoots per explant (20 ± 0.47) was recorded with 3.0 mg dm−3 BA and 1.0 mg dm−3 IAA. An anatomical study confirmed shoot regeneration via direct organogenesis. About 95 % of the in vitro shoots developed roots after transfer to half strength MS medium containing 1.0 mg dm−3 IBA. 95 % of the plantlets were successfully acclimatized and established in soil. The transplanted plantlets showed normal
flowering without any morphological variation. 相似文献
12.
L. -J. Ou Z. Chen X. -J. Dai L. -X. Deng Y. -L. Qiu H. Li P. Liu M. -Z. Liang S. Luan L. -B. Chen 《Photosynthetica》2008,46(3):395-399
Contents of chlorophylls and carotenoids in yellow-green mutant Biao 810S were approximately half those in control type 810S.
Biao 810S had fewer grana lamellae and looser structure than 810S, lower volume of starch granules in chloroplasts, but under
high temperature and high irradiance the net photosynthetic rate (P
N) of Biao 810S was higher than that of 810S. The chlorophyll fluorescence parameter Fv/Fm of Biao 810S was little higher and photochemical quenching qP was obviously higher than those of 810S. No significant differences in P
N and biomass were observed in their hybrid combination. The yellow-green mutant phenotype may be a useful genetic marker of
P(T)GMS rice used for hybrid seed production. 相似文献
13.
Hybrids including Hystrix patula, H. duthiei and H. longearistata were obtained and genetic relationships among them were studied. Meiotic pairing in hybrids of H. duthiei × Psathyrostachys juncea (Ns), H. longearistata × Psa. juncea (Ns), Leymus multicaulis (NsXm) × H. duthiei, L. multicaulis (NsXm) × H. longearistata, Elymus sibiricus (StH) × H. patula, Roegneria ciliaris (StY) × H. patula, R. ciliaris (StY) × H. duthiei and R. ciliaris (StY) × H. longearistata averaged 5.76, 5.44, 11.94, 10.88, 10.08, 3.57, 0.46 and 0.90 bivalents per cell, respectively. The results indicated that
H. duthiei and H. longearistata had the NsXm genomes of Leymus, while H. patula contained the StH genomes and had a low genome affinity with the StY genomes of Roegneria. Results of genome-specific RAPD assay were comparable with the chromosome pairing data. According to the genomic system
of classification in Triticeae, H. patula should be considered as Elymus hystrix L., while H. duthiei and H. longearistata as Leymus duthiei and Leymus duthiei ssp. longearistata, respectively. 相似文献
14.
X. Wei Y. S. Jiang S. Y. Jiang X. X. Qi Z. C. Xiong W. H. Ye Z. M. Wang 《Photosynthetica》2008,46(2):312-314
Saturation (SI) and compensation (CI) irradiances [μmol(photon) m−2 s−1] were 383.00±18.40 and 12.95±0.42 for wild C. nitidissima (in mid-July) and 691.00±47.39 and 21.91±1.28 for wild C. sinensis, respectively. C. nitidissima is a shade tolerant species, whereas C. sinensis has a wide ecological range of adaptability to irradiance. Both wild and cultivated C. nitidissima demonstrated low maximum net photosynthetic rate, maximum carboxylation rate, maximum electron transfer rate, and SI, which
indicated low photosynthesis ability of leaves that were unable to adapt to strong irradiance environment. Both C. nitidissima and C. sinensis demonstrated strong photosynthetic adaptabilty in new environments. Hence proper shading may raise photosynthetic efficiency
of cultivated C. nitidissima and promote its growth. 相似文献
15.
We present a chlorophyll fluorometer module system which adapts the intensity to the individual leaf sample by adjusting the
quantum flux density of the excitation light so that the fluorescence signal is kept constant. This is achieved by means of
a feedback power adjustment of the fluorescence exciting laser diode. Thus, the intensity of the excitation light is adapted
to the actual need of a particular sample for quantum conversion without applying exaggeratedly high quantum flux density.
We demonstrate the influence of the initial laser power chosen at the onset of irradiation and kept constant during fluorescence
rise transient within the first second. Examples are shown for measuring upper and lower leaf sides, a single leaf with different
pre-darkening periods, as well as yellow, light green and dark green leaves. The novel excitation kinetics during the induction
of chlorophyll fluorescence can be used to study the yield and regulation of photosynthesis and its related non-photochemical
processes for an individual leaf. It allows not only to sense the present state of pre-darkening or pre-irradiation but also
the light environment the leaf has experienced during its growth and development. Thus, the individual physiological capacity
and plasticity of each leaf sample can be sensed being of high importance for basic and applied ecophysiological research
which makes this new methodology both innovative and informative. 相似文献
16.
A bacterial artificial chromosome (BAC) library of banana (Musa acuminata) was used to select BAC clones that carry low amounts of repetitive DNA sequences and could be suitable as probes for fluorescence
in situ hybridization (FISH) on mitotic metaphase chromosomes. Out of eighty randomly selected BAC clones, only one clone gave a
single-locus signal on chromosomes of M. acuminata cv. Calcutta 4. The clone localized on a chromosome pair that carries a cluster of 5S rRNA genes. The remaining BAC clones
gave dispersed FISH signals throughout the genome and/or failed to produce any signal. In order to avoid the excessive hybridization
of repetitive DNA sequences, we subcloned nineteen BAC clones and selected their ‘low-copy’ subclones. Out of them, one subclone
gave specific signal in secondary constriction on one chromosome pair; three subclones were localized into centromeric and
peri-centromeric regions of all chromosomes. Other subclones were either localized throughout the banana genome or their use
did not result in visible FISH signals. The nucleotide sequence analysis revealed that subclones, which localized on different
regions of all chromosomes, contained short fragments of various repetitive DNA sequences. The chromosome-specific BAC clone
identified in this work increases the number of useful cytogenetic markers for Musa. 相似文献
17.
The common bean (Phaseolus vulgaris L.) is sensitive to high temperature, while an ecologically contrasting species (Phaseolus acutifolius A. Gray) is cultivated successfully in hot environments. In this study, the two bean species were respectively acclimated
to a control temperature of 25 °C and a moderately elevated temperature of 35 °C in order to compare the thermotolerance capabilities
of their photosynthetic light reactions. Growth at 35 °C appeared to have no obvious adverse effect on the photosynthetic
activities of the two beans, but changed their thermotolerance. After a short period of heat shock (40 °C for up to 4 h),
the photosynthetic activities of 25 °C-grown P. vulgaris declined more severely than those of P. acutifolius grown at 25 °C, implying that the basal thermotolerance of P. vulgaris is inferior to that of P. acutifolius. But after acclimating to 35 °C, the thermotolerances of the two species were both greatly enhanced to about the same level,
clearly demonstrating the induction of acquired thermotolerance in their chloroplasts, and P. vulgaris could be as good as P. acutifolius. Temperature acclimation also changed plants’ resistance to photoinhibition in a manner similar to those toward heat stress.
In addition, acquisition of tolerance to heat and strong irradiance would reduce the dependency of the two beans on xanthophyll
pigments to dissipate heat, and also seemed irrelevant to the agents with antioxidant activities such as SOD. 相似文献
18.
19.
A rapid and efficient plant regeneration protocol for a wide range of alfalfa genotypes was developed via direct organogenesis. Through a successive excision of the newly developed apical and axillary shoots, a lot of adventitious
buds were directly induced from the cotyledonary nodes when hypocotyl of explants were vertically inserted into modified Murashige
and Skoog (MS) medium supplemented with 0.025 mg dm−3 thidiazuron (TDZ) and 3 mg dm−3 AgNO3. When the lower part of shoots excised from explants were immersed into the liquid medium with 1.0 mg dm−3 α-naphthaleneacetic acid (NAA) for 2 min, and then transferred to hormone free half-strength MS medium, over 83.3 % of the
shoots developed roots, and all plantlets could acclimatize and establish in soil. The protocol has been successfully applied
to eight genotypes, with regeneration frequencies ranging from 63.8 to 82.5 %. 相似文献
20.
Epicotyl segments of kumquat (Fortunella crassifolia Swingle cv. Jindan) were transformed with Agrobacterium tumefaciens GV3101 harboring neomycin phosphotransferase gene (npt II) containing plant expression vectors. Firstly, the explants were cultured in darkness at 25 °C on kanamycin free shoot
regeneration medium (SRM) for 3 d, and then on SRM supplemented with 25 mg dm−3 kanamycin and 300 mg dm−3 cefotaxime for 20 d. Finally, they were subcultured to fresh SRM containing 50 mg dm−3 kanamycin monthly and grown under 16-h photoperiod. Sixty five kanamycin resistant shoots were regenerated from 500 epicotyl
explants after four-month selection. Shoot tips of 20 strong shoots were grafted to 50-day-old kumquat seedlings and survival
rate was 55 %. Among the 11 whole plants, 3 were transgenic as confirmed by Southern blotting. This is the first report on
transgenic kumquat plants, and a transformation efficiency of 3.6 % was achieved. 相似文献