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31.
In broccoli heads grown in spring and in autumn, and harvested at four various developmental stages antioxidant ability as well as certain indices of plant senescence were investigated. Development of broccoli heads was accompanied by losses of chlorophyll and ascorbic acid. At pre-florescence stage accumulation of soluble phenolics was observed. Activity of peroxidase in the initial stage of growth increased significantly and its high level was mantained during the whole growing period. The profound evolution of ethylene was manifested by plants of the pre-florescence stage. In broccoli grown in spring the higher contents of chlorophyll and phenolics in comparison with the autumn experiment were observed, as well as slightly higher activities of peroxidase and catalase. Total antioxidant activity was considerably higher in spring than in autumn.  相似文献   
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芥蓝植株再生体系的优化   总被引:5,自引:0,他引:5  
采用正交设计方法对影响芥蓝植株再生体系的因素进行了优化研究,结果表明:影响芥蓝植株再生的最主要因素是外植体类型,其次依次为NAA,BAP,蔗糖和AgNO3。结果进一步显示,最利于芥蓝再生植株的培养基条件为:MS BA P2mg/L NAA0.03mg/L 1%蔗糖 AgNO3 7.0mg/L 0.8%琼脂,最适宜的外植体类型为下胚轴,植株再生频率高达97.5%。  相似文献   
34.
AIMS: To identify Lactococcus garvieae isolates from radish and broccoli sprouts and compare them with virulent and less virulent mutant strains obtained from yellowtails with regard to KG phenotype, presence of a capsule and virulence towards yellowtails and mice. METHODS AND RESULTS: Comparative 16S rRNA gene sequence analysis of six isolates obtained from radish and broccoli sprouts indicated that they were L. garvieae (similarity >99%). They were compared with KG9502, Lg2 and ATCC49156 strains obtained from yellowtails. A less virulent mutant strain Lg2-S was obtained by Lg2 subculture. Biochemical characterization of the six strains resembled that of KG9502, Lg2, ATCC49156 and Lg2-S, except for saccharose and tagatose acidification and the presence of hippuricase. These six strains were nonpathogenic towards yellowtails and mice, nonsusceptible to bacteriophages and demonstrated heterogeneity on pulsed-field gel electrophoresis analysis. Using transmission electron microscopy, a capsule was observed in KG9502 and Lg2 but not in ATCC49156 and Lg2-S. CONCLUSIONS: We isolated L. garvieae strains that lacked pathogenicity towards yellowtails and mice from radish and broccoli sprouts; these were noncapsulated and exhibited KG(+) phenotype. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first documentation of L. garvieae isolated from terrestrial plants. These isolates exhibited genetic diversity; however, they were noncapsulated and nonpathogenic towards yellowtails and mice.  相似文献   
35.

Aims

The objective of this study was to show whether the edible part of broccoli has antibacterial and antifungal activity against micro‐organism of importance in human health and vegetable spoilage, and to test if this effect was partially due to antimicrobial peptides (AMPs).

Methods and Results

Crude extracts were obtained from florets and stems of broccoli cultivar Avenger and the inhibitory effect was demonstrated against pathogenic bacteria (Bacillus cereus, Staphylococcus xylosus, Staphylococcus aureus, Shigella flexneri, Shigella sonnei, Proteus vulgaris), phytopathogenic fungi (Colletotrichum gloeosporioides, Asperigillus niger) and yeasts (Candida albicans and Rhodotorula sp.). It was shown that samples treated with proteolytic enzymes had a reduction of approximately 60% in antibacterial activity against Staph. xylosus, suggesting that proteinaceous compounds might play a role in the inhibitory effect. Antimicrobial components in crude extracts were thermoresistant and the highest activity was observed under acidic conditions. It was shown that antifungal activity of broccoli's crude extracts might not be attributed to chitinases.

Conclusions

Organic broccoli cultivar Avenger has antimicrobial activity against pathogenic bacteria, yeast and phytophatogenic fungi. Data suggest that this effect is partially due to AMPs.

Significance and Impact of the Study

Broccoli's crude extracts have activity not only against pathogenic bacteria but also against phytophatogenic fungi of importance in agriculture. We suggest for first time that the inhibitory effect is probably due to AMPs.  相似文献   
36.
The objective of the present study was to determine if boron (B) retranslocation depends on plant-B status and external-B supply. The stable 10B isotope was supplied to the root system of broccoli ( Brassica oleracea var. italica Plenck cv. Commander) and lupin ( Lupinus albus L. cv. Ultra) plants to provide a quantitative picture of B distribution during early reproductive development. Regardless of the B regime (i.e. continuous supply with luxury, sufficient or deficient B; transfer at inflorescence emergence from either a luxury- or sufficient-B supply to a deficient one) and whether 10B was acquired before or during inflorescence development, a significant proportion of the B recovered in broccoli florets and lupin fruit was 10B enriched. B acquired during inflorescence development was an important source of B for reproductive structures, but the relative importance of B acquired before and after inflorescence emergence appeared to be species dependent. The occurrence of B retranslocation was not dependent upon the induction of B deficiency. The concentrations of B in phloem exudates (0.38 to 0.03 mM) were 4- to 23-fold those in xylem sap, and more similar to the concentrations in the reproductive structures (0.86 to 0.07 mM) than those in source leaves (2.4 to 0.19 mM). The decreasing acropetal gradient of tissue-B concentrations with luxury-B supply declined dramatically or was reversed in plants grown with sufficient or deficient B. The data are consistent with B being a phloem-mobile element, and suggest that newly acquired B is particularly important during the early reproductive growth of plants.  相似文献   
37.
根肿病是十字花科蔬菜作物的主要病害之一,造成了蔬菜产业巨大经济损失。青花菜是一种重要的十字花科蔬菜,具有良好的防癌保健功效。近年来青花菜根肿病在我国浙江、云南等青花菜主产区发生日益严重,鉴定和筛选青花菜抗根肿病资源,从而培育抗病品种是防治该病最经济有效的方法。为挖掘和丰富可利用的根肿病抗源,本试验针对我国优势根肿菌小种—4号小种,利用苗期人工接种鉴定方法—伤根灌菌法对531份青花菜及其近缘种属材料进行了抗根肿病鉴定。结果显示,446份青花菜材料(其中高代自交系393份,杂交种53份)中缺乏高抗(HR)和抗病(R)材料,包括中抗(MR)材料5份,均为自交系,占供试种质的1.12%,感病(S)材料189份,占供试种质的42.38%,高感(HS)材料252份,占供试种质的56.50%。85份近缘种属材料(其中甘蓝9份,花椰菜32份,大白菜7份,芜菁4份,芥蓝12份,苤蓝8份,菜心8份,油菜2份,野生种2份,欧洲山芥1份)中,包括免疫(I)材料1份,高抗(HR)材料1份,抗病(R)材料5份,中抗(MR)材料2份,感病(S)材料39份,高感(HS)材料37份。总体上高抗青花菜材料缺乏,近缘种属材料中抗源材料比例略高,这些材料为青花菜及甘蓝类蔬菜抗根肿病病育种提供了抗性资源。  相似文献   
38.
青花菜雄性不育系选育研究初报   总被引:1,自引:0,他引:1  
以具有细胞质雄性不育基因的青花菜不育材料CMS94008为不育源,通过杂交和连续回交的方法选育出不育性稳定、经济性状良好的一批青花菜胞质雄性不育系,并以CMS92100、CMS93-2、CMS9905、CMS95234等不育材料及其转育父本为代表,对不育系的主要特征及农艺性状进行系统的观察鉴定。  相似文献   
39.
40.
目的:以西兰花无菌苗为材料,对影响西兰花再生的各种素进行研究,建立并优化西兰花的再生体系.方法:用组织培养法,对西兰花的外植体进行诱导生芽、生根.结果:不同品种的再生率差别较大,珠绿和青秀两个品种的再生率达91%以上,而鼎丰一号仅为80.3%;培养6 d 的下胚轴分化能力最强;当培养基中添加3 mg/L 6-BA 和0.2 mg/L IAA 时,下胚轴的分化率最高,玻璃化程度也降到最低;当培养基中添加0.2 mg/L IBA 或0.2 mg/L NAA时,可成功诱导不定芽生根.结论:建立并优化了西兰花再生体系,为西兰花遗传转化体系的建立奠定了基础.  相似文献   
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