共查询到20条相似文献,搜索用时 15 毫秒
1.
S. Kumar Sunil Kumar S. P. Negi J. K. Kanwar 《In vitro cellular & developmental biology. Plant》2008,44(6):474-479
Callus cultures derived from leaf segments of chrysanthemum cultivar ‘Snow Ball’ which was susceptible to Septoria obesa were successfully used for in vitro selection for resistance to this pathogenic fungus. Resistant cell lines were selected by culturing callus on growth medium
containing various concentrations of S. obesa filtrate. Resistant calluses obtained after two cycles (30 d each cycle) of selection were used for plant regeneration. About
30% of the plants regenerated from the resistant calluses and 70–80% of the plants raised from cuttings had acquired considerable
resistance against the pathogen in the field. No phenotypic variation was observed in the selected regenerates. 相似文献
2.
Dmitar Lakušić 《Biologia》2008,63(5):631-636
The south-European Cardamine plumieri Vill. (sect. Pteroneurum subsect. Cryptopterum) is confirmed for the Flora of Serbia. Several populations were discovered in the central and western part of country, exclusively
on the serpentine bedrocks. Morphological, chorological and ecological characteristics of C. plumieri was studied. 相似文献
3.
4.
Peter G. Wilson 《Kew Bulletin》2008,63(2):347-349
Summary The type specimen of Metrosideros regelii is discussed. It contains a mixture of two species, representing different genera, and a lectotype is chosen. The generic
position of the species is considered in the light of morphology and recent molecular evidence and the new combination, Mearnsia regelii, made. 相似文献
5.
The research on incidence of mistletoe (Viscum album ssp. abietis) on silver fir (Abies alba) was carried out in natural fir stands in Croatia. In the area of Gorski Kotar 32.8 % of the examined dominant fir trees
were infected with mistletoe. The mistletoe incidence was presented according to the damage degrees of silver fir from 0 (healthy
trees) to 4 (dead trees), rated by the crown defoliation and needle discoloration. With the increase of incidence, mistletoe
spreads more onto more vital, i.e. less damaged trees. In the Dinaric Alps 28.6% of the examined fir trees were infected,
this percentage amounting to 27.1% for the mountainous regions between the Sava and Drava rivers.
The site and stand parameters (exposure, elevation, site quality, forest community and crown closure) were analysed in order
to establish whether there was a correlation between these parameters and mistletoe incidence. There was a negative correlation
between the elevation and mistletoe incidence. Among the compartments with a closed stands there were considerably less compartments
with higher mistletoe incidence than among compartments with a sparsely closed and understocked stands. The other analysed
site and stand parameters individually had no significant influence on mistletoe incidence.
The correlation of silver fir mortality in 2004 and mistletoe incidence in 2002/03 was analysed, and their strong correlation
was established. Mistletoe could be considered as a bioindicator of silver fir decline, and probably a significant contributor
to that decline. In the areas where mistletoe incidence is great it can be presumed that silver fir is significantly damaged. 相似文献
6.
Gaye Öngen Gaye Güngör Bahar Kanberoglu 《World journal of microbiology & biotechnology》2007,23(4):519-524
Aspergillus section Nigri strains Aspergillus aculeatus Ege-K 258, A.
foeditus var. pallidus Ege-K156, A. niger Ege-K 4 and A. tubingensis Ege-K 265 were used to treat olive mill wastewater (OMW) in an investigation aimed at exploring their dephenolisation and
decolourisation ability and, consequently, the economic feasibility of using any or all of these strains in a pre-treatment
step in the processing of OMW. Of these strains A. tubingensis Ege-K 265 resulted in an 80% decolourisation of twofold-diluted OMW and a 30% decolourisation of undiluted OMW; in addition,
it was able to remove approximately 30% of all phenolic compounds in both twofold-diluted and undiluted OMW. We conclude that
A. tubingensis Ege-K 265 could be effectively used in the pre-treatment step of a combined aerobic-anaerobic process to solve the environmental
problems caused by OMW in Mediterranean countries. 相似文献
7.
Amr El-Sayed Abdulwahed Ahmed Hassan Saleh Natour Amir Abdulmawjood Michael Bülte Wilfried Wolter Michael Zschöck 《Journal of microbiology (Seoul, Korea)》2009,47(3):253-259
The aim of the present study is to evaluate the efficiency of three methods to determine the molecular diversity of 34 Mycobacterium avium subsp. paratuberculosis (MAP) strains isolated from 17 cattle herds. The applied methods included the analysis of sequence polymorphism of the mononucleotide
(G1 and G2) and trinucleotide sequences (GGT) of the Short Sequence Repeats (SSR) and the determination of size polymorphism
of 9 different Mycobacterial Interspersed Repetitive Units (MIRU) and 6 Variable Number Tandem Repeats (VNTR). Sequence analysis
of SSR of 34 isolates showed 4, 6, and 2 alleles of G1, G2, and GGT repeats, respectively. The amplification of the investigated
9 MIRU units revealed only two discriminatory genotyping systems (MIRU2 and MIRU3). Out of 6 VNTR PCR differentiation methods,
only one method could be recommended for genotyping purposes. The profile 7g-12g-4ggt-II-b-2 of the combination systems G1-G2-GGT-MIRU2-MIRU3-VNTR1658
dominates among the examined isolates and was detected in 14.7% of the isolates. The use of certain repetitive loci of SSR,
MIRU, and VNTR techniques in this study showed greater potential than others for the characterization of MAP isolates. The
recommended loci can be used for the epidemiological tracing of MAP field strains and to determine the relationships between
isolates in different herds. 相似文献
8.
Indeok Hwang Dilli Prasad Paudyal Seong-Ki Kim Hyeonsook Cheong 《Biotechnology and Bioprocess Engineering》2007,12(2):157-164
Inhibitors are very important in the study of hormone function. Brasinazole (Brz) is a specific inhibitor of brassinosteroids
(BRs) biosynthesis. To expand our knowledge of the molecular mechanisms of plant steroid signaling, we performed genetic screening
using medium containing Brz under dark conditions. Mutants insensitive to Brz developlonger hypocotyls than their wild type
counterparts. We isolatedabz453 as a Brz insensitive mutant. TAIL-PCR and the segregation ratio of T2 plants indicated a single T-DNA insertion at the 24-Sterol
C-methyltransferase (SMT2) gene in theabz453 mutant. Recapitulation for putative FCP serine phosphatase (FSP), the gene neighboringSMT2, indicated no significant phenotypes, but theSMT2 anti-sense (SMT2-AS) line developed longer hypocotyls than the wild type in medium containing Brz. Additionally, theSMT2-AS line displayed similar phenotypes to theabz453 line in soil including enhanced growth and smaller silique. Theabz453 andSMT2-AS mutants showed phenotypes similar to those of wild type in medium containing benzylaminopurine, pacrobutrazol and ACC (precursor
for ethylene) under dark conditions. However, when brassinolide (BL) dose response was observed, theabz453 andSMT2-AS lines showed higher sensitivity than wild type. Theabz453/det2 andabz453/bri1-119 double mutants showed enhanced growth compared to thedet2 andbri1-119 line under both dark and light conditions. Specially, in dark conditions double mutants displayed nearly 2- and 1.5-fold
longer hypocotyls thandet2 andbri1-119 plants. Brz insensitivity to theSMT2 knock-out mutant and phenotypes of double mutants indicate that not only do BRI1 and DET2 influence the BRs response, as
evidenced by hypocotyl elongation, but another sterol derived signals may also be affected in mutants, suggesting that another
pathway is involved in hypocotyl elongation due to SMT2. 相似文献
9.
Septobasidium parviflorae sp. nov. on Pinus parviflora is described and illustrated. This species is characterized by its whitish-gray, gray to dark gray-colored fungus body with
an indeterminate margin, hyphal strands, and cylindrical basidia with long sterigmata. This is the first report of Septobasidium occurring on a member of the genus Pinus in Japan. 相似文献
10.
Summary
Psychotria kupensis Cheek is described as a new species in Psychotria sect. Confertiflorae Hiern. Attention is drawn to its monopodial, dwarf, litter-gathering and adventitious root-forming habit and to its anomalous
stipules. The species appears to be endemic to the submontane evergeen forest of Mt Kupe in Cameroon. Its conservation status
is assessed. 相似文献
11.
S. E. Dawson 《Kew Bulletin》2008,63(3):517-517
Summary The name Pavetta modesta (Hiern) S. E. Dawson is a later homonym of P. modesta Bremek. Pavetta crystalensis is proposed as a new name. 相似文献
12.
Martina Koch Erich Möstl Hanspeter W. Steinmetz Marcus Clauss Juan F. Masello Petra Quillfeldt 《Polar Biology》2009,32(2):281-285
Glucocorticoid (GC) hormones rise in response to stressors, including natural events including weather or predator presence,
and human activities, such as hunting, scientific research or recreational visits. However, because blood sampling itself
causes stress and is dangerous or even impossible in some wildlife species, feedback-free methods for GC determination are
needed to assess stress in these animals. Faecal GC analyses have thus gained interest. Here, we validate a non-invasive method
to estimate the physiological stress in the Upland goose Chloephaga picta. An adrenocorticotropin hormone (ACTH) challenge was conducted in captive adults (female and male), and droppings were collected
before, during and after the experiment. Corticosterone metabolite (CM) secretion in response to the ACTH challenge was measured
with several enzyme immunoassays (EIA) to find the most appropriate test. We used CM levels during the periods before and
after the experiment as control data. An EIA for 11-oxoetiocholanolone achieved the highest response to the ACTH challenge
and also reflected a stress response to unfamiliar environment. Furthermore, CM concentrations of dry samples were highly
correlated with the corresponding non-dried (frozen) samples. The data suggest that this method is appropriate to measure
the stress in Upland geese, and that samples can be stored either frozen or dry form. 相似文献
13.
Sheng-Hui Xue Xin-Juan Luo Zhen-Hua Wu Hui-Li Zhang Xin-Yu Wang 《Plant Cell, Tissue and Organ Culture》2008,92(3):251-260
To explore the possibility of an effectively long-term preservation of the germplasm of the HR lines of medicinal plant Astragalus membranaceus, Gentiana macrophylla Pall., and Eruca sativa Mill., both cold storage and cryopreservation approaches were attempted and compared. After 5-month cold storage on half
strength Murashige and Skoog (1962) (1/2 MS) agar medium (AM), up to 82.9, 75.7, and 100% of the A. membranaceus, G. macrophylla and E. sativa hairy roots (HRs) recovered growth, respectively. The survival rates of A. membranaceus and G. macrophylla HRs significantly decreased, whereas that of E. sativa HR was unchanged with the addition of increased levels of exogenous abscisic acid (ABA) during cold storage. Using the encapsulation–vitrification
(EV) method for cryopreservation, the G. macrophylla HRs died, whereas up to 6 and 73% of the A. membranaceus and E. sativa HRs survived, respectively. The HR lines evaluated with both methods showed no significant differences in morphology and
growth rate compared with controls that were not subjected to preservation methods. These results suggest that cold storage
is a more suitable alternative for the HR lines of the three studied plant species and that specificity of plant species have
profound effects on the effectiveness of preservation. 相似文献
14.
R. Ramirez-Malagon I. Aguilar-Ramirez A. Borodanenko L. Perez-Moreno J. L. Barrera-Guerra H. G. Nuñez-Palenius N. Ochoa-Alejo 《In vitro cellular & developmental biology. Plant》2007,43(6):660-665
Mammillaria species are the most numerous within Cactaceae family, and some of them are threatened with extinction as a result of human
activities. In this work, results of in vitro propagation are presented for ten Mammillaria species, testing 20 combinations of indole-3-acetic acid (IAA) and kinetin. Best results on shoot formation were obtained
using kinetin at two levels: 27.9 and 46.5 μM. All IAA levels tested were able to induce de novo shoot formation in M. bocasana, M. densispina, M. hahniana, M. hutchisoniana, M. orcutii, M. pectinifera, M. perbella, M. picta, M. rhodantha, and M. zephyranthoides. Depending on the IAA level tested, four responding groups were observed concerning their highest shoot-formation number.
For all species, the highest average of shoot formation was achieved with 5.7:46.5 or 11.4:46.5 μM IAA/kinetin, yielding 4.8
and 4.7 shoots per explant, respectively, in 60 d. Rooting of regenerated shoots was achieved by leaving the explants in their
shoot-induction medium or transferring them to half-strength MS medium. Hardening of regenerated plants was successfully achieved
by planting them in peat moss substrate after a desiccation treatment at room temperature for 3 d. 相似文献
15.
G. Lorda J. D. Breccia V. Barbeito F. Pagliero S. Boeris C. Castaño A. Pordomingo F. Altolaguirre M. D. Pastor 《World journal of microbiology & biotechnology》2007,23(1):1-5
The addition of xanthan to high water retention capacity peat (HWRC) inoculants did not show differences on the survival of
Bradyrhizobium japonicum E109. In low water retention capacity peats (LWRC) however, xanthan increased the survival of B.japonicum significantly. Xanthan showed the best effect at 0.1 g/l for B. japonicum, in contrast to Sinorhizobium fredii USDA205 where the concentrations evaluated (0–1.0 g/l) did not affected significantly its survival. Nevertheless, when the
symbiotic performance on soybean was evaluated, the presence of 0.1 g xanthan/l increased the nodule number for both strains. 相似文献
16.
A general in vitro cloning system was established for four Helleborus species: H. argutifolius, H. foetidus, H. niger and H. orientalis. The plant material was introduced in vitro from axillary buds. A Murashige and Skoog (MS)—based medium (Murashige and Skoog
1962) was used supplemented with 2% (w/v) sucrose, 2-isopentenyladenine (2-iP) and 6-benzylaminopurine (BA). Multiplication
rates depended on the genotype and varied from 1.3 for H. foetidus till 3.8 for H. niger. The first results showed that the rooting phase could be done ex vitro. Rooting was induced by a drench for one week in
a solution of indole-3-butyric acid (IBA -3 mg l−1) and 1-naphthaleneacetic acid (NAA-1 mg l−1) at 5°C. 相似文献
17.
As a step toward greater understanding of the genetics of verticillium wilt resistance in plants, we report the sequencing
of a candidate wilt resistance gene, mVe1, from the mint diploid model species, Mentha longifolia (Lamiaceae). mVe1 is a putative homolog of tomato (Solanum lycopersicum L.) verticillium wilt (Ve) resistance genes. The mVe1 gene has a coding region of 3,051 bp. The predicted mVe1 protein contains a leucine-rich repeat domain, a common feature of plant disease resistance proteins. We compared 13 mVe1 alleles from three mint species. These alleles shared 96.2–99.6% nucleotide identity. We analyzed four M. longifolia populations segregating with respect to mVe1 alleles and wilt resistance versus susceptibility and found one association between mVe1 genotype and wilt phenotype. We conclude that mVe1 may play a role in mint verticillium wilt resistance, but variation for resistance in our segregating progenies is likely
polygenic. Therefore, further investigations of mVe1 and identification of additional candidate genes are both warranted. 相似文献
18.
E. S. Kostryukova V. N. Lazarev V. M. Govorum 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2008,2(2):148-159
Inclusion membrane proteins (Inc-proteins) belong to the family of unique chlamydial proteins. Members of this family attract attention of scientists because Inc-proteins are localized in the inclusion membrane, they have been found in all chlamydial species, expression of the most part of their genes begins during the first hours after the infection of cell culture. Biological functions of Inc-proteins remain unknown, but these proteins are suggested to play a key role in process of the development of the chlamydial infection. 相似文献
19.
Kamiel Spoelstra Serge Daan 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2008,194(3):235-242
Mutations in each of the genes mPer1, mPer2, mCry1 and mCry2 separately cause deviations from the wild type circadian system. Differences between these mutant strains have inspired the
hypothesis that the duality of circadian genes (two mPer and two mCry genes involved) is related to the existence of two components in the circadian oscillator (Daan et al., J Biol Rhythms 16:105–116,
2001). We tested the predictions from this theory that the circadian period (τ) lengthens under constant illumination (LL)
in mCry1 and mPer1 mutant mice, while it shortens in mCry2 and mPer2 mutants. mCry1
−/−
and mCry2
−/−
knockout mice both consistently increased τ with increasing light intensity, as did wild type mice. With increasing illumination,
rhythmicity is reduced in mCry1, mCry2 and mPer1, but not in mPer2 deficient mice. Results for mPer mutant mice are in agreement with data reported on these strains earlier by Steinlechner et al. (J Biol Rhythms 17:202–209,
2002), and also with the predictions from the model. The increase in cycle length of the circadian system by light in the
mCry2 deficient mice violates the predictions. The model is thereby rejected: the mCry genes do not play a differential role, although the opposite responses of mPer mutants to light remain consistent with a functional Evening–Morning differentiation. 相似文献
20.
Binh-Nguyen Truong Koei Okazaki Toshimitsu Fukiharu Yuko Takeuchi Kazuyoshi Futai Xuan-Tham Le Akira Suzuki 《Mycoscience》2007,48(4):222-230
Toxocysts of the genus Pleurotus are blastoconidia-like ovoid structures surrounded by a liquid droplet containing a toxin that paralyzes nematodes. This
study investigated toxocyst development using a strain S396 of Pleurotus cystidiosus subsp. abalonus (subgen. Coremiopleurotus). The surface of the liquid droplet was found to be an elastic envelope. When a nematode touches the toxocyst, the envelope
adheres to the worm and bursts. Toxocysts are induced simultaneously with coremia formation in the absence of nematodes and
developed only from aerial hyphae in which nuclear division had ceased. In the early stage of toxocyst development, liquid
springs repeatedly from the tip of the sterigma-like stipe before ovoid (blastoconidium-like structure) formation. A certain
substance in the liquid might polymerize to form the envelope while the ovoid simultaneously budded in the droplet. The nucleus
tends to locate near the toxocyst, especially in early stage of toxocyst development. Each dikaryotic cell predominantly formed
one or two toxocyst(s) while each monokaryotic cell predominantly formed one. In rare cases, a nucleus existed in the toxocyst,
suggesting the possibility that the toxocyst is a vestigial blastoconidium. 相似文献