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81.
新疆圆柏黄酮类成分的研究   总被引:1,自引:0,他引:1  
采用硅胶、Sephadex LH-20柱等色谱手段,对新疆圆柏叶的黄酮类成分进行了研究,从中分离鉴定了9个黄酮类化合物:柏木双黄酮(Ⅰ)、柏木双黄酮4',4'-二甲醚(Ⅱ)、穗花杉双黄酮(Ⅲ)、罗汉松双黄酮A(Ⅳ)、儿茶素(Ⅴ)、槲皮素(Ⅵ)、异高黄芩素7-O-β-D-木糖苷(Ⅶ)、杨梅素3-O-β-D-葡萄糖苷(Ⅷ)和芦丁(Ⅸ).其中化合物Ⅰ、Ⅱ、Ⅴ、Ⅶ、Ⅷ和Ⅸ为首次从该植物中分离得到,化合物Ⅷ和Ⅸ为首次从该属植物中分离得到.二苯代苦味肼基自由基(DPPH·)清除活性测试结果表明,化合物Ⅴ和Ⅵ的抗氧化活性较高,与阳性对照品抗坏血酸的接近;黄酮苷类化合物Ⅷ、Ⅷ和Ⅸ次之,而双黄酮类化合物Ⅰ、Ⅱ、Ⅲ和Ⅳ活性较差.  相似文献   
82.
沙地柏抗旱性的研究   总被引:1,自引:0,他引:1  
对沙地柏(Sabina vulgaris Ant.)的抗旱特性及形态解剖特征进行了研究测试,发现沙地柏叶片小,大部分退化为磷片状,气孔少且凹陷,栅状组织发达,无海绵组织,角质层厚,机械组织强化。且具有束缚水与自由水值高、其子叶内水势低、蒸腾速率低等抗旱性强的特点,是一种优良的固沙树种。  相似文献   
83.
S. Liu    K. Yu    S. J. Park 《Plant Breeding》2008,127(1):62-68
Common bacterial blight (CBB) of common bean ( Phaseolus vulgaris L.), is one of the major diseases that decrease yield and quality. A major quantitative trait locus (QTL) for CBB resistance from line XAN 159 was transferred into two bean lines, HR45 and HR67. Previous studies identified that two markers are linked to this QTL but the chromosome location was not consistent. To identify more tightly linked markers and to verify the chromosome location, 65 additional markers were mapped using 81 recombinant inbred lines (RILs) derived from a cross HR67 × OAC95-4. The QTL was mapped to a 13 cM region on chromosome 1 and defined by eight molecular markers that explained 25–52% of the phenotypic variation. Six tightly linked amplified fragment length polymorphism markers (0.6–9.7 cM from the QTL peak) were converted into seven sequence tagged site markers, three of which were mapped to this QTL. Five tightly linked markers were used to screen 907 F2 plants derived from a cross HR45 × 'OAC Rex' and four of them were linked to each other within 4.2 cM. These markers may be useful in marker-assisted selection and map-based cloning of this major QTL.  相似文献   
84.
甜菜源库关系的研究   总被引:6,自引:1,他引:5  
为阐明源、库的关系对甜菜产量形成的影响。运用比较生理学的方法,研究了不同特性甜菜品种群体源、库的形成及其相互关系以及源、库发展在产量形成中的作用。结果表明,甜菜群体LAI和LAD可作为衡量源大小及能力的重要指标。光合源的同化能力直接影响着块根库容的大小,后期较大的光合源会抑制块根库的扩大,影响甜菜产量的形成。揭示了丰产、高糖甜菜品种的源库关系,LAI峰值出现在块根及糖分增长期,最大LAI应在4.3以上,达到峰值后要有20 d左右的相对稳定持续期,糖分积累后期LAI应保持在2.4左右。群体LAD应在块根及糖分增长期达到19.3 m2.d以上,后期呈缓慢下降变化。以上结果可为指导甜菜生产实践提高产量提供理论依据。  相似文献   
85.
铜绿微囊藻和小球藻室内竞争实验研究   总被引:1,自引:0,他引:1       下载免费PDF全文
对铜绿微囊藻和小球藻进行藻类竞争实验,并通过模拟计算,分别得到铜绿微囊藻和小球藻纯培养和竞争条件下的生长模式,并计算了2种藻之间的相互竞争抑制强度。纯培养时铜绿微囊藻和小球藻的增长速率r分别为0.451/d和0.419/d,最大环境容量K分别为1414×104个/mL和812×104个/mL;混合培养时铜绿微囊藻对小球藻的种间竞争强度为1.44,小球藻对铜绿微囊藻的种间竞争强度为0.9。  相似文献   
86.
Selective absorption (SA) of K over Na (i.e. the preferential absorption of K over Na) has been proposed as a Na tolerance mechanism but genotypic variation for this trait has not been assessed with sugar beet in the field. Thus, the aim of this study was to explore the variation of SA in 14 sugar beet cultivars and to relate SA with yield and root quality in two sites of central Greece (Amfithea and Pyrgetos). Genotypic variation for SA was significant and the SA values were higher in Pyrgetos, the site with the lower soil K and Na concentrations. In Pyrgetos, a favourable environment for sugar beet growth, cultivars yielded more and root quality was better. In that site, a negative relationship between SA and yield (fresh root weight, sugar yield) was found indicating that strong Na exclusion from root is a disadvantage for high yielding. Negative SA–yield relationships were evident in Amfithea when five cultivars with very low SA values (<1.00) were excluded from the analysis. Combined all the cultivars, curvilinear functions were the best-fitted curves for the SA–yield relationships. In Amfithea, where sugar beets had lower water content in root (WCR), a significant, positive correlation between SA and % sucrose content in fresh root weight was found. This finding was ascribed to the dilution of sucrose in roots due to the increased WCR as a result of the increased root Na concentration. In both sites, SA was positively related with root K concentration and negatively with Na concentration. The positive correlations between SA and root α-amino N concentration indicated that sugar beet N nutrition could be affected by the genotypic ability to exclude Na from the root.  相似文献   
87.
Fleet dynamics was addressed for three cephalopod taxa of commercial interest, the squid Loligo vulgaris, the octopuses Octopus vulgaris and Eledone cirrhosa, and the cuttlefish Sepia officinalis, for 48 trawlers of the fish trawling fleet. Landing profiles (LP) were identified based on the species composition of the landings using hierarchical cluster analysis. Four out of a total of 12 different LP were related to cephalopods and other species associated with them.The effects on the landing proportions of a number of variables, year, season and vessel, are analysed for each of the species studied using generalized linear models (GLM). The factor “vessel”, including an ensemble of technical characteristics as well as the abilities of individual skippers, explained most of the model deviance, strongly reinforcing the existence of a fleet component dedicated to catch cephalopods. However, time also explains much of the variation found in the data.Seasonal alternation between landings of octopodidae and cuttlefish was observed within a small group of old trawlers operating mainly off the south coast, following the abundance cycles of these species. For a larger group of more modern trawlers, operating off the western coast, inter-annual shift between octopus and squid was found, together with a well marked seasonal pattern between the catches of cephalopods and horse mackerel.Spatial patterns of activity were identified using vessel monitoring system (VMS) data available for trawlers in Portugal, demonstrating the existence of cephalopod targeting strategies in Portuguese fish trawling activities.  相似文献   
88.
The instablity of the stimulation of photosynthate unloading from seed coats of Phaseolus vulgaris by abscisic acid (ABA ) and benzylamino purine ( BAP ) was studied in terms of experimental conditions. ABA stimulated photosynthate unloading at pH 6 and pH 8 without close dependence upon pH. ABA at a concentration range of 10-5-10-4 mol/L displayed stimulatory effect. However, BAP revealed no effect at a concentration range of 10-6-10-4 mol/L. Experiments designed with different transport time of 14C-photosynthate indicated that ABA might act at the plasma membrane of the unloading cells. Reducing endogenous ABA level by diminishing leaf area did not facilitate the manifestation of exogenous ABA function. Potassium ion stimulated photosynthate unloading from seed coats with highest promotion at 100 mmol/L K . However, no dependence of ABA stimulation of photosynthate unloading on K was found.  相似文献   
89.
真蛸人工繁殖初步试验   总被引:5,自引:2,他引:3  
2005年春、秋两季在福建省大成水产良种繁育试验中心开展了真蛸(Dctopus vulgaris)人工繁殖初步试验.引进本地海区真蛸亲体48头,获得受精卵216万粒,孵化出幼体139万头,在春季成功培育着底幼蛸121头.开口饵料配置试验表明,卤虫无节幼体、轮虫、桡足类可作为真蛸幼体的开口饵料,以卤虫无节幼体为最佳.  相似文献   
90.
The relationships between environmental factors and fluctuations in Octopus vulgaris landings in the northern Alboran Sea are studied from 1987 to 2007. Landings during this period show both a long term decrease and a strong inter-annual variability. An exploratory phase revealed that local coastal temperatures and those averaged for the whole Alboran Sea during the previous year were the main factors controlling such variability. Warm anomalies have a detrimental effect on the octopus landings on the following year and this suggests that the decreasing trend in octopus landings could be partially linked to the long term warming observed in the Western Mediterranean. It is not yet clear which are the specific mechanisms linking warm anomalies to landing decrease. Nevertheless some hypotheses are proposed and a statistical model is developed for attempting to predict octopus landings one year ahead.  相似文献   
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