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排序方式: 共有389条查询结果,搜索用时 18 毫秒
1.
辽宁省菜田生态系统组分优势值与系统优势度分析 总被引:2,自引:1,他引:1
辽宁省菜田生态系统组分优势值与系统优势度分析周宝利,葛晓光李宁义(沈阳农业大学园艺系,110161)(沈阳市城建中专,110013)AnalysisonSuperiorityValueandDominanceDegreeofVariousCompon... 相似文献
2.
A convenient method using commercial aqueous concentrated HCl (conc. HCl; 35%, w/w) as an acid catalyst was developed for preparation of fatty acid methyl esters (FAMEs) from sterol esters, triacylglycerols, phospholipids, and FFAs for gas-liquid chromatography (GC). An 8% (w/v) solution of HCl in methanol/water (85:15, v/v) was prepared by diluting 9.7 ml of conc. HCl with 41.5 ml of methanol. Toluene (0.2 ml), methanol (1.5 ml), and the 8% HCl solution (0.3 ml) were added sequentially to the lipid sample. The final HCl concentration was 1.2% (w/v). This solution (2 ml) was incubated at 45°C overnight or heated at 100°C for 1–1.5 h. The amount of FFA formed in the presence of water derived from conc. HCl was estimated to be <1.4%. The yields of FAMEs were >96% for the above lipid classes and were the same as or better than those obtained by saponification/methylation or by acid-catalyzed methanolysis/methylation using commercial anhydrous HCl/methanol. The method developed here could be successfully applied to fatty acid analysis of various lipid samples, including fish oils, vegetable oils, and blood lipids by GC. 相似文献
3.
Ralstonia solanacearum (RS) race 1 biovar 4 (R1bv4), causal agent of bacterial wilt in vegetable sweet potato (VSP), is often latent in VSP vines and is important in introduction of the pathogen to newly planted fields. In this study, the effects of biological and environmental factors on the distribution and multiplication of R1bv4 in VSP tissues were examined. Based on stem-injection inoculation, the R1bv4strain of NC01 could cause 49.0% and 33.0% wilting on VSP cultivars TN71 and WS, respectively. The populations of NC01 in diseased TN71 and WS were 108–109 cfu/g tissue at 28th day after inoculation. On the other hand, the R1bv4 could not cause symptom in cultivars of TN57 and VSPSL-1 vine and the NC01 was confined to near the injection sites. Temperature tests indicated that NC01 could cause 28.0% and 14.0% wilting on cultivar TN71 at 28 and 20°C, respectively. Moreover, the populations of NC01in diseased plants were 1.6 × 109 and 7.9 × 108 cfu/g tissue at 28 and 20°C, respectively. The distribution of NC01 in VSP stem indicated that the isolation frequency of NC01 was lower than 31.0% in terminal shoots or erect stems and 45.0 to 100.0% in creeping stem after 8 wks planted in infested soil (106 cfu/g soil). The results demonstrated that terminal shoots or erect stems were not common carrier for transmitting R1bv4. Furthermore, two R1bv4 strains, NC01 and HsinT01, were examined the ability for latent infection on cv. TN71. The results revealed that NC01 and HsinT01 showed different ability of latent infection on cultivar TN71. NC01 had lower percentage (46.8% and 45.1%) than HsinT01 (93.4% and 75.3%) at 20 and 28°C. 相似文献
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高氧对果蔬采后生理影响研究进展 总被引:4,自引:0,他引:4
高氧(21%-100%O2)贮藏是近几年发展起来的果蔬采后处理技术之一.概述了高氧对果蔬采后生理如呼吸作用、乙烯合成、组织褐变、活性氧代谢及抗氧化能力、风味等方面的影响,还介绍了高氧对病原微生物生长和采后果蔬腐烂控制的作用. 相似文献
6.
烟粉虱对几种常见蔬菜寄主的取食选择性 总被引:1,自引:0,他引:1
在多种蔬菜寄主同时存在的情况下,烟粉虱对寄主的选择性和嗜好性排序为:黄瓜>节瓜,番茄,菜豆>芥蓝,茄子>甘蓝,苦瓜。 相似文献
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8.
Muwaffaq Ramadan Karajeh 《Archives Of Phytopathology And Plant Protection》2013,46(20):2492-2500
Saccharomyces cerevisiae is a promising plant growth-promoting yeast for different crops. Applicability of S. cerevisiae as a biocontrol agent of the root-knot nematode (Meloidogyne javanica) was investigated on cucumber under growth-room and field conditions. The yeast S. cerevisiae similar to the nematicide, Ethoprophos, when applied as a rhizospheric soil drench treatment led to an obvious reduction of root galling caused by M. javanica and resulted in reducing the nematode reproduction ability on cucumber under growth room and field conditions. The yeast was more effective at 10 than at 5?g/l. Furthermore, the application of S. cerevisiae resulted in improving cucumber plant growth and increasing its fruit yield. High content of total phenolics in cucumber roots of S. cerevisiae-treated plants and hydrogen peroxide-treated plants gives a clue on the ability of the yeast to induced plant resistance in a similar way to exogenous hydrogen peroxide. 相似文献
9.
Tetsuko Takabe Mikio Nishimtjra Takashi Akazawa 《Bioscience, biotechnology, and biochemistry》2013,77(10):2137-2142
The isolation of the photosynthetically competent chloroplast preparations was undertaken by means of the density gradient centrifugation on the modified silica sol “Percoll.” A clear separation of the intact chloroplast sustaining the high photosynthetic activities (light dependent CO2 fixation ca. 130μmol/mg Chl·hr) was established. The contamination of mitochondria and peroxisomes was estimated to be less than 3% by measuring the activities of their marker enzymes. The chloroplasts were proved to be free from endoplasmic reticulum and cytosol. The photosynthetic CO2 fixation of the isolated chloroplast preparations was saturated by illumination of the light intensity of 20,000 Lux (12 mW/cm2, 400~750 nm). 相似文献
10.
E. Bocchieri 《Plant biosystems》2013,147(5-6):1179-1196
Abstract Presented herevin are the results of research on the flora and vegetable landscape of the isola delle Bisce (NE Sardinia). The flora was found to be composed of 230 entities (1 Gymnospermae, 229 Angiospermae) belonging to 47 families and included in 156 genera. Failure to find numerous species is underscored and an overview of the vegetation landscape based on aerial photography is presented, with the identification of the vegetation formations and sites on the islands most sensitive to anthropic impact. 相似文献