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1.
Volatile components of field- and glass greenhouse-grown tomatoes(Lycopersicon esculentum MILL., variety, V. R. Moscow) of differentmaturities were studied by gas-liquid and thin-layer chromatography.The following components were separated and identified: isobutylalcohol, isopentyl alcohol, hexyl alcohol, 2-methyl-3-hexanol,isovaleraldehyde, caproaldehyde, benzaldehyde, furfural, isopentylacetate, isopentyl butyrate, isopentyl isovalerate, butyl hexanoate,hexyl hexanoate, methyl salicylate and -pinene. Chromatogramswere consistent for both field- and greenhouse-grown tomatoesat all stages of maturity. Except for isovaleraldehyde and hexylalcohol, the biosynthesis of volatile components increased alongwith the growth of fruit. Isovaleraldehyde and hexyl alcohol,presumed to give the "green leafy" aroma of tomatoes, were foundto be in their highest concentrations at the breaker and thelarge-green stages, respectively. 1This research was supported by a research grant—UI 00449—fromthe National Center for Urban and Industrial Health, U. S. PublicHealth Service.  相似文献   
2.
Studies on Cellular Site of Calcium Action in Promoting Pollen Growth   总被引:1,自引:0,他引:1  
Studies were conducted to determine cellular site of Ca action in promoting pollen growth of Crinum asiaticum and a few other species. The following experimental results have strongly indicated that Ca binding takes place in pectins of the pollen tube walls. This appeared to increase the wall rigidity and to regulate permeability of the pollen cells thereby enhancing pollen growth. Radioactive Ca incorporation was observed exclusively in the pollen tube wall regions. The promoting action of Ca on pollen growth disappeared when pectinase was supplemented to the media. This was not the case with cellulase and other enzymes used. Methyl donors promoted pollen growth, and the promotion was more than doubled if Ca ions were present. Ethionine, on the other hand, inhibited tube elongation and exhibited no Ca effect. Growth of pollen tubes in oscillaled liquid media during elongation was poorer than growth in standing media. The Ca effect was also reduced when pollen was oscillated. The observations made of the reduced rate of 45Ca incorporation when pollen was washed in water, and the hydroxylamineferric chloride test, have indicated that a considerable portion of these pectins are cold-water soluble.  相似文献   
3.
Brewbaker, James L., and Beyoung H. Kwack. (U. Hawaii, Honolulu.) The essential role of calcium ion in pollen germination and pollen tube growth. Amer. Jour. Bot. 50(9): 859–865. Illus. 1963.—A pollen population effect occurs whenever pollen grains are grown in vitro. Small pollen populations germinate and grow poorly if at all, under conditions which support excellent growth of large pollen populations. The pollen population effect is overcome completely by a growth factor obtained in water extracts of many plant tissues. This factor is shown to be the calcium ion, and its action confirmed in 86 species representing 39 plant families. Other ions (K+, Mg++, Na+) serve in supporting roles to the uptake or binding of calcium. The high requirement of calcium (300–5000 ppm, as Ca (NO3)2·4H2O, for optimum growth) and low calcium content of most pollen may conspire to give calcium a governing role in the growth of pollen tubes both in vitro and in situ. It is suspected that ramifications of this role extend to the self-incompatibilities of plants and to the curious types of arrested tube growth distinguishing, for example, the orchids. A culture medium which proved its merit in a wide variety of pollen growth studies included, in distilled water, 10% sucrose, 100 ppm H3BO3, 300 ppm Ca (NO3)2·4H2O, 200 ppm MgSO4·7H2O and 100 ppm KNO3.  相似文献   
4.
Bioinsecticides are important in the control of disease vectors, but data regarding their physiological effects on target insects are incomplete. This study describes morphological changes that occur in the midgut of third instar Aedes aegypti L. (Diptera: Culicidae) following treatment with a methanolic extract of Annona coriacea (Magnoliales: Annonaceae). Dissected midguts were subdivided into anterior and posterior regions and analyzed by light and scanning electron microscopy. Insects exposed to the extract displayed intense, destructive cytoplasmic vacuolization in columnar and regenerative midgut cells. The apical surfaces of columnar cells exhibited cytoplasmic protrusions oriented toward the lumen, suggesting that these cells could be involved in apocrine secretory processes and/or apoptosis. We report that A. coriacea extracts induced morphological alterations in the midgut of A. aegypti midgut larvae, supporting the use of plant extracts for control of the dengue vector.  相似文献   
5.
越南铁线莲属一新种   总被引:3,自引:0,他引:3  
本文描述的产于越南的毛茛科Ranunculaceae铁线莲属Clematis一新种C. hagiangensis N. T. Do是欧亚大陆第一个具单性花的种, 在花构造方面与单性铁线莲组单性铁线莲亚组sect. Aspidanthera Spach subsect. Dioicae (Prantl) W. T. Wang的种类近缘, 但叶均为单叶, 萼片呈卵形或宽卵形而不同。在单性铁线莲亚组的种, 叶通常为复叶, 只在C. dimorphophylla W. T. Wang和C. variifolia W. T. Wang同时为单叶和复叶, 此外萼片呈长圆形、倒披针形或狭卵形。  相似文献   
6.
Granulysin (GNLY) is found in cytotoxic granules of cytolytic T lymphocytes and natural killer (NK) cells, which are critical for hepatitis B virus (HBV) clearance. GNLY cytotoxicity plays an important role in the defense against viruses or intracellular bacteria. We hypothesized that genetic variation in the GNLY gene could affect the resistance of hosts against HBV infection. We compared the distribution frequencies of GNLY polymorphisms between an HBV-induced chronic liver disease (CLD) group and a spontaneous recovery (SR) control group to determine whether GNLY polymorphisms play a role in HBV clearance. A total of 117 patients in the SR group and 230 patients in the CLD group were enrolled. Samples derived from complex infections, including hepatitis C and human immunodeficiency virus, and those associated with insufficient clinical information (10 samples in SR and 24 samples in CLD) were excluded from the study. The final analysis included 107 SR and 206 CLD samples. DNA was extracted from peripheral blood, and GNLY genotypes were determined by the GoldenGate(?) method. The genotype distribution of the single-nucleotide polymorphisms (SNPs) rs2886767 (C>T), rs1561285 (G>C), and rs11127 (T>C) were significantly different between the SR and CLD groups in a recessive model (p<0.015). These three SNPs were in a complete linkage disequilibrium (LD) block. Diplotype distributions of haplotype (HT) 1 (C-G-T) and HT2 (T-C-C) were significantly different between the SR and CLD groups in a recessive model (p=0.025) and a dominant model (p=0.008). All p-values remained significant after multiple comparisons. GNLY polymorphism genotypes and diplotypes were associated with the chronicity of HBV. These data suggested that genetic variation of GNLY may be an important factor in HBV clearance through the CD8+ T or NK cell-mediated removal of HBV-infected cells from the host.  相似文献   
7.
报道了7个楼梯草属和赤车属植物(荨麻科)新纪录,它们分别为锐齿楼梯草(E. cyrtandrifolium),变黄楼梯草(E. xanthophyllum),对叶楼梯草(E. sinense),宽叶楼梯草(E. platyphyllum),托叶楼梯草(E. nasutum),短叶赤车(P. brevifolia)和华南赤车(P. grijsii)。列出了各个物种的标本引证和地理分布情况。  相似文献   
8.
The purification and characterization of thermostable chaperonin of the thermosome family from hyperthermophilic archaeon Thermococcus profunds are described. The purified thermosome is a homooligomeric complex and an ATPase with maximal activity at 80 degrees C. The electron micrographs obtained from negatively stained as well as frozen-hydrated specimen showed an eight-fold symmetry of chaperonin. They were about 15 nm height and 16 nm in diameter with a central cavity of 5 nm. In order to understand the ATPase cycling of thermosome, we analyzed the oligomeric structure of thermosome treated with several nucleotides.  相似文献   
9.
The lipid peroxidation (as malondialdehyde, MDA), activities of superoxide dismutase (SOD) and catalase (CAT), and benzo[a]pyrene (BaP) metabolites were investigated in sera and erythrocytes of male Sprague-Dawley rats treated with BaP (20 mg per rat). MDA levels were significantly increased in sera (16.98+/-3.29 nmol/ml serum, P<0.05) 12 h after BaP treatment and persisted up to 96 h (13.80+/-1. 65 nmol/ml serum, P<0.05), but no significant change in NIDA levels was observed in erythrocytes. SOD and CAT activities were significantly increased in erythrocytes shortly after BaP exposure, and they were slightly decreased in sera, indicating an inverse correlation between lipid peroxidation and antioxidant enzyme activity. BaP and BaP-quinones (BaP-1,6-quinone and BaP-3,6-quinone) were measured in sera during the study period. A rapid increase of unmetabolized BaP was observed in sera (41.27+/-4.14 pmol/ml serum) 3 h after BaP treatment, reaching a peak at 6 h (48.56+/-4.62 pmol/ml serum) followed by a sharp decrease. Formation of the BaP-1, 6-quinone and BaP-3,6-quinone started in sera 3 h after BaP treatment, reached a peak at 24 h (7.23+/-1.02 pmol/ml serum) and 12 h (9.20+/-0.98 pmol/ml serum), respectively, and then decreased gradually. The time-dependent pattern of serum lipid peroxidation and the level of erythrocyte antioxidant enzymes were shown to be related to the concentrations of the BaP-quinone metabolites. These results suggest that BaP treatment, probably via the formation of BaP-quinones, oxidatively altered lipids and antioxidant enzymes in the blood, and might be associated with BaP-related vascular toxicity including carcinogenesis.  相似文献   
10.
Female moths of Lyclene dharma dharma (Arctiidae, Lithosiinae) produced three pheromone components (I-III), which strongly stimulated male antennae. Using GC-MS analysis and chemical derivatizations, the following structures were estimated: 6-methyl-2-octadecanone (I), 14-methyl-2-octadecanone (II), and 6,14-dimethyl-2-octadecanone (III). While the stereochemistry of the chiral centers could not be determined because it was difficult to collect a sufficient amount of the natural pheromone, the plain structures of I and II were confirmed by synthesis of the racemic mixtures starting from diols. These methyl-branched ketones have not been identified as a natural product, indicating that they constitute a new chemical group of lepidopteran female sex pheromones.  相似文献   
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