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191.
192.
New icetexane diterpenes (1-2); 8, 11, 13-icetexatriene-10-hydroxy, 11, 12, 16-tri acetoxyl (1) and 8, 11, 13-icetexatriene-7, 10, 11-dihydroxy-12, 13-dihydrofuran (2) along with six known compounds namely acetoxy syranzaldehyde (3), syranzaldehyde (4), coniferaldehyde (5), lupeol (6), betulin (7), and 4-(4-methoxy phenyl)-2-butanone (8) were isolated from the roots of Premna tomentosa. The structures of compounds 1 and 2 were established by detailed spectral analysis using UV, IR, 1H NMR, 13C NMR, 1D, 2D and Mass. The newly isolated compounds were screened for rat intestinal α-glucosidase inhibitory and free radical (DPPH) scavenging potentiality. The new icetexane diterpenes (1, 2) and compound 3 were found to have significant α-glucosidase inhibitory and also free radical scavenging (DPPH) activities.  相似文献   
193.
近年来,油茶产业迅速升温,良种苗木的缺乏制约了油茶产业的发展,其中良种壮苗和适地适树适种源,特别是良种采穗圃建设与管理是关键因素.文章综述了油茶优良无性系采穗圃品种配置方法、营建、管理、采穗以及建档等.  相似文献   
194.
1 设立公路动物防疫监督检查站的重要性与紧迫性 赣州市位于江西省南部,辖18县、市(区),境内有105、323、206、319国道纵贯或横穿,是江西及湖南、湖北、四川、重庆、河南、山东、安徽。东北乃至内蒙古等省、市、自治区装载活畜的车辆进闽入粤的必经之地。装载活畜的车辆自北向南或由西向东途径数千公里驰进赣南,如此长时间、远距离行驶,途中感染疫源的确在所难免。危险的是这些车辆有的消毒不严,或者不接受消毒;有的装载病、死畜或隐性症状的活畜(禽),沿途抖落粪便和污染物;有的车主甚至乱抛或贱卖病死牲畜,致…  相似文献   
195.
Powdery mildew incited by Golovinomyces cichoracearum has become a serious problem on sunflower in India during the past 2–3 years. Genetic resistance in the released cultivars and the parental lines of hybrids is rather limited. Hence, screening of about 420 accessions comprising of wild Helianthus species, interspecific derivatives, core germplasm, inbred lines and few exotic accessions was done under natural field conditions for 2 years and further confirmed by screening under artificial inoculation conditions. PCR analysis using primers specific to powdery mildew causing genera gave a 391 bp band which confirmed the pathogen as G. cichoracearum. Seven different screening methods were tested which induced infection, but dusting of spores on to the healthy leaves proved to be convenient and more effective method of infection. Based on the differential response of the accessions derived from diverse genetic backgrounds, a scale for obtaining reliable estimates of the disease has been devised. Among different cultivar germplasm accessions, the disease severity index (DSI) ranged from 15 to 100 and area under disease progression curve (AUDPC) ranged from 95 to 648. Among the four groups of cultivated sunflower accessions tested, DSI and AUDPC was in the order of exotic lines < interspecific derivatives < inbred lines < core germplasm. Reliable sources of resistance to the pathogen were identified in four annual wild species (H. argophyllus, H. agrestis, H. debilis, H. praecox), six perennials (H. angustifolius, H. atrorubens, H. rigidus, H. salicifolius, H. pauciflorus and H. resinosus), two interspecific derivatives (HIR-1734-2, RES-834-3) and two exotic lines (PI 642072, EC-537925).  相似文献   
196.
槲蕨水提物对3种杂草的化感效应研究   总被引:1,自引:0,他引:1  
以槲蕨(Drynaria fortunei (Kunze)J.Sm)为供体植物,分别以黑麦草(Lolium perenneL.)、紫花苜蓿(Medicago sativa Linn.)和紫云英(Astragalus sinicus)为受体,研究不同浓度槲蕨水提物对3种杂草种子萌发和幼苗生长的化感作用.取槲蕨新鲜叶制成0.5 g/mL的水提液,分别用浓度为0、0.1、0.25、0.5 g/mL的水提液来培养3种杂草(黑麦草、紫花苜蓿和紫云英)种子,统计种子萌发率及测量幼苗长度.结果表明:不同浓度的槲蕨水提物对黑麦草、紫花苜蓿和紫云英的发芽率及幼苗生长有显著的抑制效应,但不同浓度水提物对不同杂草的影响存在差异,3种杂草对槲蕨水提物敏感性大小顺序为黑麦草>紫花苜蓿>紫芸英.说明槲蕨可作为一种生物除草剂资源加以利用.  相似文献   
197.
Tassar silk fiber (Antheraea mylitta) was irradiated with the available maximum dose range upto 100 kGy using 8 MeV electron beam at room temperature. Irradiation effect in these fibers is quantified in terms of the changes in microstructural parameters studied using wide-angle X-ray scattering data (WAXS). The crystal imperfection parameters such as crystallite size (〈N〉), lattice strain (g in %), and surface weighted crystallite size (Ds in Å) have been determined by line profile analysis (LPA) using Fourier method of Warren. For this purpose, exponential, lognormal, and Reinhold functions for column length distribution have been used for the determination of these parameters. These parameters were compared with tensile properties of the fibers. The increasing trend of crystallite size values (〈N〉 as well as Ds in Å) and tenacity (gf/den) with increasing dosage of radiation clearly indicates the cross linking polymer network in fiber. Comparison of SEM photographs also confirms the X-ray results.  相似文献   
198.
ABSTRACT

The sugar-accumulating potential of global and local sweet and grain sorghum varieties were tested under the local conditions. The basis for this study was the dependency of sugar accumulation on temperature and photoperiod. Thus, the efficacy of cultivars as a bioenergy source would need to be determined based on their performance under the local environmental conditions. A strong correlation of sucrose content with brix was observed, enabling large-scale screening of varieties for high sucrose content. The morphological characteristics inherent in sweet sorghum, such as tall stems, greater number of leaves and a longer vegetative period, were found to correlate with the total stem sugar content. Assessment of sugars along the stem revealed maximum sugar accumulation in the upper intermediate to upper internodes in most of the varieties tested. The maximum theoretical ethanol yield (MTEY), a function of brix and juice yield, was determined as a better indicator of testing the performance of a variety as a potential source of bioethanol, mainly due to a negative correlation of stem juiciness and sucrose content in the varieties tested. Further, the relative expression of vacuolar invertase genes, SbINV1 and SbINV2, was studied, and a strong negative correlation of SbINV2 to stem sucrose content was observed. This reveals a possibility of involvement of vacuolar invertase gene, SbINV2, in sugar accumulation in sweet sorghum stems, and as a key candidate for molecular breeding studies for higher stem sugar content.  相似文献   
199.
A micropropagation protocol was established for a medicinal plant Vitex negundo. Genetic stability of micropropagated plants was investigated. Multiple shoots were induced from nodal explants cultured on Murashige and Skoog (MS) medium with 0.53 μM naphthalene acetic acid (NAA) and 11.0 μM benzyl aminopurine (BAP) along with additives (ascorbic acid, 283.9 μM; citric acid, 130.1 μM; and arginine, 143.6 μM). Shoots were further multiplied by repeated transfer of the mother explant. The shoots were further multiplied on MS medium + 0.57 μM indole-3-acetic acid (IAA) and 6.6 μM BAP. The micropropagated shoots were pulse treated with 122.5 μM indole-3-butyric acid (IBA), in liquid MS medium and then transferred to autoclaved soilrite. These rooted ex vitro. Shoots were also rooted in vitro on a half-strength MS medium + 2.45 μM IBA. The survival rate of in vitro rooted plantlets was poor during hardening compared to ex vitro rooted plantlets. About 95% of the ex vitro rooted, hardened plantlets survived in the field. Genetic stability of micropropagated plants was tested by using 25 random amplified polymorphic DNA primers. The cloned plants exhibited no variation in banding pattern in comparison with the mother plant.  相似文献   
200.
Summary Semilooper resistant transgenic castor plants were produced through Agrobacterium-mediated genetic transformation method. Two castor cultivars, Jyothi and VP1 were transformed using the super-binary vector pTOK233 carrying gus A and hpt genes. Putative transformants were regenerated following selection on the hygromycin containing medium. GUS positive primary transformants, when subjected to Southern analysis, revealed stable integration of gus A into their genomes. In the T1 generation, a monogenic segregation ratio of 3 GUS positive: 1 GUS negative plants was observed. Furthermore, transformation experiments were carried out with the Agrobacterium pSB111 super-binary vector carrying a synthetic delta endotoxin gene cryIAb and the herbicide resistance gene bar both driven by cauliflower mosaic virus 35S promoter. Putative transformants were regenerated through selection on the phosphinothricin containing medium and Basta tolerant transformants were subjected to molecular analysis. PCR analysis revealed the presence of both bar and cryIAb genes in the Basta tolerant primary transformants. Southern analysis of PCR positive plants with cryIAb probe showed a 3 Kb band upon HindIII digestion and a > 6 Kb band with BamHI digestion, thus suggesting stable integration of cryIAb intact expression cassette and independent nature of the transformants. The primary transformants subjected to ELISA disclosed varied levels of Cry protein. These transgenics expressing cryIAb – when bioassayed against freshly hatched semilooper larvae – induced substantial (> 88%) insect mortality. Southern analysis of 2T1 plants revealed the presence of cryIAb gene, indicating stable inheritance of the transgene into the next generation. In T1, all the Southern-positive plants for cryIAb invariably exhibited tolerance to Basta, denoting co-segregation of both bar and cryIAb genes. Transgenics, expressing cryIAb exhibited ample resistance against the castor semilooper.  相似文献   
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