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991.
You Xu Guibin Wang Fuliang Cao Cancan Zhu Guangyu Wang Yousry A. El-Kassaby 《New Forests》2014,45(6):765-776
Response of growth and secondary metabolites to light intensity are useful measurements to determine suitable silviculture treatments for the cultivation of medicinal plants. Here, we analyzed the growth, flavonols (total flavonol, quercetin, kaempferol, and isorhamnetin) content, flavonols yield per plant, and expression of flavonoid biosynthesis-related genes in 2-year Ginkgo (Ginkgo biloba L.) seedlings at four different light intensities (100, 76, 40, and 25 % of full sunlight) in a greenhouse setting. Across all light intensities, the 76 % sunlight treatment produced the highest growth of total biomass, root, stem, and leaf, indicating negative effects of either fulllight or heavy shading on Ginkgo seedling development. Both flavonols (total flavonol, quercetin, kaempferol, and isorhamnetin) content and expression of flavonoid biosynthesis-related genes [PAL (Phenylalanine ammonia-lyase), CHS (Chalcone synthase), F3H (Flavanone 3-hydroxylase), and FLS (Flavonol synthase)] in leaves were highest under 100 % sunlight, suggesting that full sunlight promotes the expression of flavonoid biosynthesis-related genes and increases flavonoid biosynthesis. The highest and lowest flavonol contents were found in leaves and stems, respectively. The 76 % sunlight treatment produced the highest flavonols yield while the 100 % sunlight produced the highest flavonoids content in leaves, indicating that flavonol production per unit land area depends not only flavonol content but also biomass. Overall, in order to achieve the highest flavonols yield per area in Ginkgo leaf-harvesting plantations, it is important to manipulate light conditions of field. 相似文献
992.
Fan Zhang Xueqin Wan Yangxia Zheng Lingxia Sun Qibing Chen Yalin Guo Xiaoqiong Zhu Min Liu 《Agroforestry Systems》2014,88(2):343-355
The worsening of Cadmium (Cd) pollution has intensified the urban ecological environment deterioration in the world. Purifying contaminated environment using the tall, colored-leaf woody plants has been proved as an aesthetically pleasing approach. However, the effects of Cd stress on colored-leaf woody plants have been little reported. Present hydroponic experiments were carried out to study the physiological and related anthocyanin biosynthesis genes responses to Cd stress in “Quanhong Poplar” plants. The experiments consisted of four Cd levels (0, 50, 100 and 150 μM). Leaves were sampled at 5, 10, 20, 30, 40, 50, and 60 days after the first treatment for detection of related enzyme activities and genes expression. The results showed that the plants treated with 100 or 150 μM Cd presented obvious toxicity symptom, i.e. the inhibition of growth and the decrease of chlorophyll and anthocyanin contents. However, plants growth was enhanced and the synthesis of chlorophyll, anthocyanin were promoted when the plants were subject to 50 μM Cd stress. Furthermore, the activities of relative enzymes as well as their genes expression were induced, which indicated that low concentration of Cd induced the anthocyanin accumulation in “Quanhong Poplar” plants, which suggested that using “Quanhong Poplar” to purify contaminated environment would be an aesthetically pleasing approach, which would not only remediate contaminated environments but also bring landscape effects. 相似文献
993.
为了解人工林生态系统的持水性特征,采用野外实地观测和室内浸水法对3种主要人工林下苔藓和凋落物层(未分解层、半分解和分解层)的持水特性进行了研究。结果显示:①苔藓层蓄积量以混交林最高(0.52 t· hm-2),柳杉林最低(0.10 t· hm-2);凋落物层均以楠木林最高,柳杉林最低。②柳杉和水杉林间、楠木和混交林间苔藓层最大持水性差异均不明显;柳杉和水杉林凋落物半分解层和已分解层最大持水率大于未分解层,而楠木和混交林则是未分解层大于半分解层和已分解层。③各林分苔藓层吸水速率到2h后均趋于平缓,凋落物半分解层和已分解层与未分解层均在6 h后趋于平缓,苔藓和凋落物层吸水速率与浸泡时间符合V=kt b 关系,经检验达显著水平。 相似文献
994.
995.
“家具与室内装饰材料”课程是东北林业大学重点课程。本课程建设的创新之处在于面向室内装饰行业和家具行业的实际发展情况,在课堂教学环节上既注重艺术教育又注重技术教育。在实践教学过程中,强化学生创新精神和实践动手能力的培养,使课堂教学与实践紧密结合。本课程的教学改革成果可以极大的提高学生学习的主动性、创新性和积极性。 相似文献
996.
997.
农业科研副产品处置的风险与对策 总被引:4,自引:2,他引:2
文章阐述了农业科研单位处置科研副产品的风险主要来自于将农业科研副产品作为职工福利发放或赠送给其他主体、个人侵占农业科研副产品、农业科研单位不具备经营资质等,分析了农业科研副产品处置不当的危害,并提出了提高政治纪律意识和法律意识、探索农业科研副产品处置的最佳途径、加强财务监管等防范农业科研副产品处置风险的对策。 相似文献
998.
999.
以社会成员对公共体育服务的需求为切入点,采用文献资料、访谈、问卷调查和数理统计等研究方法对贵州省公共体育服务的基础设施类、信息服务类、要素保障类进行调查分析,探讨西部欠发达地区公共体育服务体系的构建。 相似文献
1000.
Yong Yang Shouqi Xie Yibo Cui Xiaoming Zhu Wu Lei & Yunxia Yang 《Aquaculture Research》2006,37(1):40-48
Triplicate groups of gibel carp Carassius auratus gibelio Bloch (initial body weight: 4.89 g) were fed for 8 weeks at 24.8–30.8°C with nine isonitrogenous and isoenergetic diets. The control diet (F1) used white fishmeal (FM) as the sole protein source. In the other eight diets (F2–F9), 40.5–100% of FM protein was substituted by poultry by‐product meal (PBM) at 8.5% increments. The specific growth rate (SGR), feed efficiency ratio, protein efficiency ratio, protein retention efficiency and energy retention rate for fish fed PBM diets (F2–F9) were all higher, but not always significantly, than those for fish fed F1. All apparent digestibility coefficients for fish fed PBM diets were lower than those for fish fed F1. Fish fed F1 had a significantly higher hepatosomatic index value than fish fed PBM diets (P<0.05). No significant (P>0.05) effect of diet was found in whole‐body moisture and fat content. Whole‐body protein and energy content for fish fed PBM diets were slightly higher than that for fish fed F1. The optimal replacement level of FM by PBM was estimated by second‐order polynomial regression to be 66.5% in protein. 相似文献