不同播期对冬小麦粒重形成及产量的影响     

张学品  高海涛  段国辉  吴少辉  杨洪强  冯伟森  牛鑫 《勤云标准版测试》2007,(12)

以4个冬小麦品种为材料,研究了不同播期条件下籽粒灌浆特征参数、粒重和产量的差异。结果表明:播期对千粒重的影响存在差异,洛旱6号、洛麦21号和豫麦49不同播期之间的籽粒千粒重存在显著差异,但播期对偃展4110的千粒重影响不大。在不同播期下,灌浆过程中平均灌浆速率、快增期灌浆速率对粒重的影响较大。播期对不同品种灌浆高峰出现的日期影响基本一致,早播期>晚播期>中播期.但较早播种时,洛旱6号、洛麦21号和豫麦49灌浆高峰出现较早,灌浆速率大,晚播时偃展4110灌浆高峰出现较早,灌浆速率大。播期对4个品种产量的影响均以中播最高,在河南旱区生态条件下,似偃展4110的春性品种适宜播期为10月中下旬,洛旱6号、洛麦21号等似豫麦49的半冬性品种适宜播期为10月中旬。  相似文献   

威海伴月湾公园景观规划设计     

牛玉霞  邵群 《农业科技与信息》2009,(8)

在城市化水平日益增长的今天,人们已经意识到城市生态环境建设的重要性,沿海城市均有公园建设和港湾绿地的营造,那么如何构建与城市自身相和谐的滨海公园,如何营造和谐港湾,将是一个盛行不衰的话题。本文以威海伴月湾公园景观规划设计为例,来诠释这一相关问题。  相似文献   

DNA recovery from agarose gels with a simple centrifuge-driven sephadex filtration     

Niu Chen Li Yun 《中国林学(英文版)》2006,8(1):32-34

Conventional methods of DNA recovery from agarose gel generally require expensive equipment, extended elution times, or considerable handling of the sample after elution. We developed a simple protocol for a quick and effective recovery of DNA from agarose gels with good yield and quality. Using a Sephadex resin filled spin column, DNA fragments of 500 bp to 6 kb in an agarose gel slice were easily recovered by a 2 min centrifugation. The recovery efficiencies were over 40%-50% and the eluted DNA can be used directly for downstream application, such as polymerase chain reactions (PCR) and restriction enzyme digestion. This method could also be used to recover large DNA fragment (48 kb) without degradation. The use of Sephadex helps to remove small molecular impurities from agarose and it also reduces the chance of clogging the column filter caused by direct contact with agarose.  相似文献   

Effects of closing mountain for forest restoration in the watershed of Miyun reservoir,Beijing     

YuXinxiao NiuJianzhi XuJunliang 《中国林学(英文版)》2004,6(3):28-35

The paper provides a systematical analysis of ecological restoration effects of natural secondary forest of closurearea in Chao Guanxi Gou, Miyun County, Beijing. The results indicate that through more than twenty years of hillclosing afforestation since 1983, canopy closure has improved almost by 0.2; forest cover rate has raised from 7.2% to 93.8%; biodiversity, tree biomass and vegetation community have increased to a great extent. Compared with the average canopy closure before hillclosing afforestation in this area, it has improved to over 0.4 in average and increased by 0.1-0.2. The forest coverage degree has reached more than 90%. Consequently, the forest plays more important roles in intercepting precipitation, improving water storage capacity of soil, decreasing the surface runoff, and preventing soil and water loss.  相似文献   

利用试差法确定林业抽样调查中的样本容量     

牛玉刚 《河北林果研究》1993,(1)

本文针对正态总体的情形,讨论了如何利用试差法确定样本容量,即利用 n=1+s~2/(Δ (?)~2)·t~2_(n-1)(a) 式反复迭代,直到求出的n值差异很小为止,这时的n值即为所求的样本容量。文中并给出了试差法在林业中的应用实例。  相似文献   

Dietary dihydroartemisinin supplementation alleviates intestinal inflammatory injury through TLR4/NOD/NF-κB signaling pathway in weaned piglets with intrauterine growth retardation     

Yu Niu  Yongwei Zhao  Jintian He  Yang Yun  Mingming Shen  Zhending Gan  Lili Zhang  Tian Wang 《动物营养（英文）》2021,7(3):667

The aim of present study was to evaluate whether diets supplemented with dihydroartemisinin (DHA) could alleviate intestinal inflammatory injury in weaned piglets with intrauterine growth retardation (IUGR). Twelve normal birth weight (NBW) piglets and 12 piglets with IUGR were fed a basal diet (NBW-CON and IUCR-CON groups), and another 12 piglets with IUGR were fed the basal diet supplemented with DHA at 80 mg/kg (IUGR-DHA group) from 21 to 49 d of age. At 49 d of age, 8 piglets with similar body weight in each group were sacrificed. The jejunal and ileal samples were collected for further analysis. The results showed that IUGR impaired intestinal morphology, increased intestinal inflammatory response, raised enterocyte apoptosis and reduced enterocyte proliferation and activated transmembrane toll-like receptor 4 (TLR4)/nucleotide-binding and oligomerization domain (NOD)/nuclear factor-κB (NF-κB) signaling pathway. Dihydroartemisinin inclusion ameliorated intestinal morphology, indicated by increased villus height, villus height-to-crypt depth ratio, villus surface area and decreased villus width of piglets with IUGR (P < 0.05). Compared with NBW piglets, IUGR piglets supplemented with DHA exhibited higher apoptosis index and caspase-3 expression, and lower proliferation index and proliferating cell nuclear antigen expression in the intestine (P < 0.05). Dihydroartemisinin supplementation attenuated the intestinal inflammation of piglets with IUGR, indicated by increased concentrations of intestinal inflammatory cytokines and lipopolysaccharides (P < 0.05). In addition, DHA supplementation down-regulated the related mRNA expressions of TLR4/NOD/NF-κB signaling pathway and upregulated mRNA expressions of negative regulators of TLR4 and NOD signaling pathway in the intestine of piglets with IUGR (P < 0.05). Piglets in the IUGR-DHA group showed lower protein expressions of TLR4, phosphorylated NF-κB (pNF-κB) inhibitor α, nuclear pNF-κB, and higher protein expression of cytoplasmic pNF-κB in the intestine than those in the IUGR-CON group (P < 0.05). In conclusion, DHA supplementation could improve intestinal morphology, regulate enterocyte proliferation and apoptosis, and alleviate intestinal inflammation through TLR4/NOD/NF-κB signaling pathway in weaned piglets with IUGR.  相似文献   

花期盐水滴灌对10份番茄种质的主要性状影响及耐盐性评价     

廖扭  刁明  崔洪鑫  牛宁  刘慧英 《新疆农业科学》2022,59(10):2486-2494

【目的】测定10个不同番茄种质的主要植株及叶片生理性状,筛选优异的耐盐碱种质,为优异耐盐新品种改良提供参考依据。【方法】以10个不同番茄种质为试材,采用花期盐水滴灌处理,以清水滴灌为对照,采用NaCl配置的盐水(6 ms/cm)全生育期滴灌盐胁迫处理。测定盐胁迫后番茄植株的株高、茎粗、相对叶绿素含量(SPAD)值、叶片丙二醛(MDA)含量、可溶性蛋白、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性。【结果】花期盐水滴灌胁迫下,不同参试番茄材料的株高、茎粗和SPAD值均不同程度降低、可溶性蛋白含量、SOD、POD和CAT 酶活性不同程度提高。采用隶属函数法和主成分分析法对10个不同番茄种质的耐盐性进行综合评价,由强到弱依次为C₃>C₁>C₅>C₉>C₈> C₂>C₇>C₆>C₁₀>C₄。【结论】花期盐水滴灌胁迫导致所有参试番茄材料叶片氧化损伤发生,生长受到抑制,并通过渗透调节和抗氧化酶促系统响应盐胁迫逆境。不同番茄材料对盐水滴灌胁迫的敏感性和耐受性存在差异。材料的耐盐性由强到弱依次为C₃>C₁>C₅>C₉>C₈>C₂>C₇>C₆>C₁₀>C₄。  相似文献   

Nutrient Accumulation and Distribution in Cotton Promoted by Removal of Mulch Film     

Zhang Zhan-qin  Zhang Li  Tian Hai-yan  Niu Yuan  Yang Xiang-kun 《东北农业大学学报(英文版)》2022,(1):33-48

Plastic film mulching affects changes in nutrient contents in soil and absorption and utilization of nutrients in plants were by changing hydrothermal condition...  相似文献   

Effects of sodium butyrate on growth performance,haematological and immunological characteristics of weanling piglets     

C. L. Fang  H. Sun  J. Wu  H. H. Niu  J. Feng 《Journal of animal physiology and animal nutrition》2014,98(4):680-685

The experiment was conducted to study the effects of sodium butyrate (SB) on growth, haematological and immunological characteristics in weanling pigs. A total of 100 male piglets (Duroc×Landrace×Yorkshire) with a body weight of 8.0 ± 0.2 kg weaned at the age of 28 days were randomly assigned to two treatments with five replicates and 10 pigs per replicate. Piglets received a basal diet (control group) or diets supplemented with 1000 mg/kg SB. The feeding trial lasted for 21 days. The results showed that dietary SB significantly decreased (p < 0.05) diarrhoea incidence of weaned piglets, but did not affect (p > 0.05) the average daily feed intake (ADFI), average daily gain (ADG) and feed to gain (F/G). Furthermore, piglets fed dietary SB had higher (p < 0.05) serum concentrations of glucose and triglycerides and lower (p < 0.05) serum concentrations of urea nitrogen, cortisol, D‐lactic acid and diamine oxidase when compared with the control group. However, dietary SB did not affect concentrations of serum albumin, total protein, insulin and glucagon (p > 0.05). There were no significant (p > 0.05) treatment effects on serum IgA and IgM, whereas serum IgG concentration and IgA+ cell count in jejunum from pigs fed SB were significantly higher (p < 0.05) than in those given the basal diet. In conclusion, the present study indicated that dietary SB significantly decreased diarrhoea incidence of weaned piglets and increased the efficiency of nitrogen utilization. Also, dietary SB could regulate and enhance the immune function of piglets by increasing the serum IgG concentration and IgA+ cell count in jejunum. Our results suggest that SB may reduce some of the adverse effects of weaning stress and play an important role in maintaining the integrity of intestinal mucosa.  相似文献   

南北方黑木耳916品种的形态特征及营养成分比较     

高国赋  罗建军  卢红玲  钮雅丽  魏宝阳 《湖南农业科学》2014,(21)

为了比较南北方黑木耳916品种的形态特征和营养成分,采用显微镜观察、分光光度计检测、ICP-AES元素分析等方法,观察了南北方黑木耳916的孢子、子实体切面,测定其主要化学成分及矿质元素的含量。结果表明,南北方黑木耳均为朵状、褐色,但南方黑木耳颜色稍浅,子实体稍小,子实体中的胶质略多于北方的;南北方黑木耳的孢子形态结构相似,均透明,呈月牙状、肾形或柱形;在营养成分上,南方黑木耳的水分、粗脂肪、蛋白质和多糖的含量高于北方黑木耳,而粗灰分和黑色素的含量低于北方黑木耳,钠、铁含量也低于北方黑木耳。  相似文献