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1.
The possibility of infection of tobacco upper leaves with tobacco mosaic virus (TMV) was examined in experiments where the inoculum was imbibed through the cut stem. The inoculum used were: a) a preparation of a virus-specific informosome-like ribonucleoproteins (vRNP) isolated from TMV-infected plants; b) a TMV preparation; or c) a mixture of TMV and vRNP. Multiplication of TMV in upper leaves was observed in neither of the variants; nevertheless in the vascular tissue and/or probably in adjoining parenchymal cells, two kinds of RNA were synthesized: of mol. w. (1.1--1.3) X 10(6) and (0.6--0.8) X 10(6). These RNA were not found in healthy plants in the presence of actinomycin D. The synthesis of genomic TMV RNA is suppressed under these conditions. Thus, some kind of abortive TMV infection takes place under the condition of experimental inoculation of plants through a cut stem. Molecular hybridization with the DNA of recombinant plasmid containing a nucleotide sequence complementary to the 3'-portion of genomic TMV RNA proves that short RNAs synthesized under the abortive infection conditions are TMV-specific. The experiments with differential temperature treatment of N-gene-containing plants under abortive infection conditions suggest that necrotization is not necessarily induced by genomic TMV RNA synthesis.  相似文献   
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The effect of sleep deprivation by 'carousel' method on spatial memory consolidation in a Morris water maze was studied in Wistar male rats after one-day learning (in accordance to a protocol by Frick et al., 2000). It was found that after fast 3-hr learning the memory trace retains during 24-hr. Twenty four hour sleep deprivation followed learning impaired consolidation of spatial memory. So the rat model of a one-day learning is suitable for the studying of neurophysiological mechanisms of sleep deprivation effects on spatial memory consolidation.  相似文献   
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Nonlinear rats, which survived after occlusion of one or two common carotid arteries (N = 30, about 30% survived) were examined. Sham-operated animals formed a control group. In animals with ischemia, the total sleep duration in a three-hour period was substantially increased as compared to control group at the expense of a substantial growth (8-9 times) of paradoxical sleep (PS) phase. In the animals with ischemia, a sharp increase in PS was observed on the first postoperation day, and then PS gradually decreased from the first to the fortieth days. The results suggest the PS involvement in the brain intrinsic reparation functions.  相似文献   
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The influence of ecological factors on variation of random PCR markers (RAPD and inter-MITE polymorphism (IMP) primers) was evaluated in two wild Triticum boeoticum populations with contrasting climatic conditions in Crimea. The proportion of variation that undergoes natural selection was compared for these two types of molecular markers. The Sapun Mountain and Baidar Valley populations differed significantly in 24.7% of the analyzed loci, with a low Nei distance between these populations (0.0324). The number of significantly different RAPD and IMP markers in the two populations was nearly equal. Testing for evolutionary neutrality showed that 13 loci (17.8%) were influenced by natural selection. The Sapun Mountain population was more dependent on natural selection (ten loci, 13.7%) than the Baidar Valley population (four loci, 5.5%). Eleven out of the 13 loci undergoing selection were amplified with IMP primers.  相似文献   
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Wild soybean (Glycine soja Sieb. & Zucc.) is the nearest relative of a soybean crop (Glycine max (L.) Merr.). Study of population genetic structure of wild-growing relatives ofgenetically modified (GM) plants in the centers of their origin is one of the main procedures before introduction of GM crops in these areas. We have studied genetic variability of nine wild growing soya populations of Primorye Territory using RAPD analysis. The level of G. soja genetic variability was considerably higher than that of G. max. We have analyzed phylogenetic relationships in the genus Glycine subgenus Soja using RAPD markers. Our data confirm validity of allocation G. gracilis in a rank of a species.  相似文献   
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Data are presented on the genetic diversity and spatial structure of the natural wild soybean population from the neighborhood of the settlement of Ekaterinovka in Primorskii krai and on the relationship between the genetic structure of this population and its spatial organization. These data are discussed in comparison with the results of studies of wild soybean populations in the Far East region of the Russian Federation and China. Recommendations are given concerning the collection of genetic wild soybean resources.  相似文献   
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