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131.
M. L. Fisher M. M. Kyle 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(2):204-212
We have examined the genetics of systemic resistance in Phaseolus vulgaris to azuki bean mosaic virus (AzMV) and cowpea aphid-borne mosaic virus (CABMV) and the relationship of this resistance to a phenotypically similar resistance to watermelon mosaic virus (WMV) and soybean mosaic virus (SMV). In P. vulgaris cv Great Northern 1140 (GN1140), resistance to SMV and WMV has been attributed to the genes Smv and Wmv, respectively, which have been shown to segregate as a unit. Systemic resistance to AzMV is conferred by two incompletely dominant alleles, Azm1 and Azm2, at unlinked loci. At least three resistance alleles must be present at these two loci for systemic resistance to be expressed in the plant. Systemic resistance to CABMV in GN 1140 is conditioned by a dominant allele that has been designated Cam2. Under some environmental conditions, a recessive allele at an unlinked locus, cam3, also controls a resistant response to CABMV. Resistance to AzMV and CABMV does not assort independently from Wmv/Smv, but also does not consistently cosegregate, suggesting that perhaps in each case one of the factors involved in resistance is associated with Smv/Wmv. 相似文献
132.
Kristel Eggermont Inge J. Goderis Willem F. Broekaert 《Plant Molecular Biology Reporter》1996,14(3):273-279
We describe here a reliable high-throughput method for extraction of RNA from fresh or frozen plant tissue that obviates laborious
and time-consuming homogenisation by mortar and pestle. The method is based on homogenisation by high-speed reciprocal shaking
in presence of a mixture of inexpensive abrasive materials; i.e., quartz sand and glass beads. After homogenisation, the method
follows a standard procedure for RNA extraction by phenol/LiCl. Yield and quality of RNA obtained by homogenisation with the
sand/glass bead mix are identical to those obtained by mortar and pestle. 相似文献
133.
The tiny seeds of parasitic weeds of the genusOrobanche can be identified by using RAPD markers. A simple procedure for DNA extraction from single seeds, 10 μg each, followed by
RAPD-PCR and using specific DNA markers, leads to species identification. Seeds of five different species could be identified
using this method. 相似文献
134.
Summary Pyrolysis mass spectrometry (PyMS) was used to produce biochemical fingerprints from replicate frozen cell cultures of mouse macrophage hybridoma 2C11-12, human leukaemia K562, baby hamster kidney BHK 21/C13, and mouse tumour BW-O, and a fresh culture of Chinese hamster ovary CHO cells. The dimensionality of these data was reduced by the unsupervised feature extraction pattern recognition technique of auto-associative neural networks. The clusters observed were compared with the groups obtained from the more conventional statistical approaches of hierarchical cluster analysis. It was observed that frozen and fresh cell line cultures gave very different pyrolysis mass spectra. When only the frozen animal cells were analysed by PyMS, auto-associative artificial neural networks (ANNs) were employed to discriminate between them successfully. Furthermore, very similar classifications were observed when the same spectral data were analysed using hierarchical cluster analysis. We demonstrate that this approach can detect the contamination of cell lines with low numbers of bacteria and fungi; this approach could plausibly be extended for the rapid detection of mycoplasma infection in animal cell lines. The major advantages that PyMS offers over more conventional methods used to type cell lines and to screen for microbial infection, such as DNA fingerprinting, are its speed, sensitivity and the ability to analyse hundreds of samples per day. We conclude that the combination of PyMS and ANNs can provide a rapid and accurate discriminatory technique for the authentication of animal cell line cultures. 相似文献
135.
Seiji Sonobe 《Journal of plant research》1996,109(4):437-448
Vacuoles in plant cells can be eliminated by centrifugation of protoplasts through a density gradient. In this review, properties
of evacuolated protoplasts, named ‘miniprotoplasts’, and the significant roles in plant cytoskeleton studies are described.
Miniprotoplasts, prepared from tobacco BY-2 cells whose cell-cycle had been synchronized at late anaphase, continued to divide
to form two daughter cells. In the presence of cytochalasin B cytokinetic cleavage was enhanced, suggesting a role of actin
filaments in plant cytokinesis. In the cytoplasmic extract of miniprotoplasts both tubulin and actin could be polymerized
to form microtubules (MTs) and actin filaments (AFs), respectively. A purification method for tubulin, actin and related proteins
was developed using the extract. To investigate the interaction between cortical microtubules and the plasma membrane, an
experimental system in which MTs were reconstructed on membrane ghosts was developed by combination of membrane ghosts and
the extract. 相似文献
136.
Ferredoxin-sulfite reductases (Fd-SiRs) [hydrogen-sulfide: ferredoxin oxidoreductase, EC 1.8.7.1] from leek leaves have been
purified to homogeneity. The enzymes (SiR 1, SiR 2 and SiR 3) were separated by Mono Q chromatography. The collective molecular
mass of the enzymes was estimated to be 65 kDa by gel filtration. In all three cases, subunit analysis by SDS-PAGE yielded
a single protein band corresponding to a molecular mass of 64 kDa, indicating that the enzymes each exist as a monomer. In
the oxidized forms, SiR 1, SiR 2 and SiR 3 all exhibited nearly identical absorption maxima at 279∼280, 389∼390, 588 and 714
nm, indicating that siroheme is involved in the catalysis of sulfite reduction. On enzymatic properties, SiR 1, SiR 2 and
SiR 3 could only react with the physiological electron donor, feriedoxin. The enzymes exhibited different heat stabilities.
The pH active curve obtained from SiR 2 was different from the others. Moreover, SiR 1 exhibited a lower Km value for ferredoxin
than SiR 2. Although the N-terminal sequence was the same, the results of some enzymatic properties, amino acid analysis,
and peptide mapping suggested the presence of the Fd-SiR isozymes in leek leaves. 相似文献
137.
The presence of species and their cover values together with soil and topographic characteristics were recorded at 40 sites along an altitudinal gradient of the Puna Belt at Pozuelos, in the High Andes in northwest Argentina. Classification and ordination of plant assemblages showed that soil and topography were the best predictors of the variation in species distribution. The different plant assemblages which occur along the topographic gradient follow the geographic variation in rainfall in this Andean region. Perennial bushes and grasses colonize the plains and slopes with fine textured soils which retain their water content. In contrast, deciduous bushes and cactuses grow on steep, rocky, dry slopes. Open woods also occur on east-facing steep, rocky slopes which are sheltered from winds. 相似文献
138.
长白山劲松林场植物群落的分类和排序 总被引:7,自引:2,他引:5
将长白山白河林业局劲松林场的54块样地用聚类分析法划分成6个植被类群,再用PC-VTAB程序中经过改进的Braun-Blanquet学派的植被排表分析法进行综合,产生了鉴别概要表,为各个等级的植被类群筛选出诊断种。此外,还用鉴别种地样地记录进行主成分分析,以验证诊断种的有效性,结果表明,PC-VTAB中的植被排表分析法是筛选鉴别种的有效方法,而鉴别种以显著地提高植被分析和排序的质量。 相似文献
139.
本文报道茄属果树可乐茄(SolanumquitoenseLam.)叶肉原生质体的分离、培养及植株再生。幼嫩叶片原生质体经酶游离、纯化后,以1×104个/ml密度培养于稍加改良K8p(附加2,4-D0.5mgL(-1)、NAA1.0mgL(-1)和BA0.5mgL(-1))的培养基中,三天后开始分裂,一周分裂3—4次。一个月形成小细胞团,植板率为0.1—0.2%,小细胞团转培养于MS+2,4-D0.5mgL(-1)上增殖后进行分化。原生质体来源愈伤组织在IAA(0.1—1.0mgL(-1))与BA或ZT组合的培养基中能诱导器官发生,芽分化率最高可达42.9%;但IAA、BA、ZT三者一起使用未见任何器官分化。小芽在MS+IAA0.2mgL(-1)中生根成植株。可乐茄叶肉原生质体的植株再生,可应用于育种和茄属植物遗传工程研究。 相似文献
140.
Abstract. The Argentine Chaco is a mosaic of grassland and open forest habitats maintained by natural disturbance activities such as fire. Since the introduction of domestic livestock and other human activities, the balance of this mosaic has been significantly altered, both in plant species and structural composition. This study focuses on the impact of such changes on the diversity of ground-dwelling arthropods within semi-arid Chaco forest. Quantitative measures of habitat structure and arthropod diversity were taken in forest areas previously subjected to grazing, logging and ploughing. Results indicated that arthropod diversity was smaller on sites with reduced structural complexity, with marked changes in arthropod family composition. The habitat components relating to plant architectural and vertical diversity were particularly influential on arthropod diversity. The guild size ratio of predatory to non-predatory arthropods also differed significantly between habitats suggesting a change in the resource base available to some groups. The latter suggests a shift in the functional organisation of the forest ecosystem which could have important repercussions for the diversity of other trophic levels. 相似文献