中国天然草地植被生长气象条件评价模型

应用模糊数学方法,构造了影响中国天然草地植被生长的光、温、水函数;通过光、温、水评价结果之间的"与"运算,建立了天然草地植被生长气象条件综合评价模型;采用积分方法,反映草地植被任意时段气象条件的时间累积影响效应;通过气象条件指数的年际对比,评价草地植被生长气象条件的优劣;最后,利用上述模型计算了2005年和2006年中国天然草地植被月、季以及主要生长期气象条件指数,并进行了对比分析、应用和效果检验。结果表明,2年不同时间尺度的气象条件指数对比结果能够客观地反映2006年中国天然草地植被生长气象条件的优劣分布,与实际产草量、株高的对比结果基本一致,应用效果较好。     

外来种互花米草入侵模式与爆发机制

互花米草（Spartina alterniflora Loisel）因其促淤造陆和消浪护堤作用显著而被许多国家引种,如今却在侵入地快速蔓延并呈现爆发趋势,对生态系统造成了极大危害,被认为是研究生物入侵生态学和遗传学的模式植物。从种群的入侵力、生态系统可入侵性和入侵通道3个方面探讨互花米草的爆发机制,研究结果表明高遗传分化和基因渗入能力是互花米草爆发的遗传基础,对逆境的高抗性和强竞争力是其快速扩张的保障,而高繁殖系数是互花米草爆发的源泉。我国互花米草种群的早期扩散人为影响超过了自然过程,快速扩张呈现出点源扩散和多点爆发的特点,从而为其种群控制带来困难,同时种子的跳跃式和连续式扩散在互花米草种群维持、更新和爆发中有重要作用,强有力的克隆生长能力也为互花米草种群的连续扩张提供了保障。现阶段要完全控制和根除互花米草是不实际的,但在及时预测预警的基础上,应用成本一效益分析方法,采取有序控制和综合开发利用的策略,仍可望妥善解决互花米草入侵所带来的负面效应。     

高温胁迫下五种杜鹃花属植物的生理变化及其耐热性比较

高温是制约分布于较高海拔地区杜鹃花迁地保育与园林应用的重要因子.为探讨杜鹃花属植物的 高温致伤机理,该实验以隶属不同亚属的白花杜鹃、羊踯躅、毛棉杜鹃、红滩杜鹃及红棕杜鹃4年生实生苗为 材料,通过人工气候箱的盆栽实验,研究了30℃、38℃高温胁迫下其叶片生理生化指标的变化,并利用隶属 函数法及系统聚类分析法对其种间...     

跟骨强度指数与影响因素相关性分析

目的：探讨跟骨强度指数与其影响因素的相关性。方法：共入选1024例体检人员。（1）通过Achilles定量超声（QUS）系统测量左跟骨强度指数;（2）使用RGC-120型体重秤测量身高、体重并计算体重指数;（3）通过问卷调查收集体检人员年龄、膳食、运动、吸烟、饮酒等影响因素的相关资料;（4）将各影响因素与跟骨强度指数进行相关分析和多元逐步回归分析。结果：（1）直线相关分析结果显示,跟骨强度指数与身高、体重、体重指数、饮用牛奶年数、运动年数呈正相关（;2）多因素逐步回归分析显示,跟骨强度指数仅与体重指数、运动年数具有显著的回归效果。结论：体重指数与运动年数是跟骨强度指数的独立影响因素,对骨质疏松的诊断与预防具有重要的意义。     

Reproduction of Meloidogyne incognita Race 3 on Flue-cured Tobacco Homozygous for Rk1 and/or Rk2 Resistance Genes

Most commercial tobacco cultivars possess the Rk1 resistance gene to races 1 and 3 of Meloidogyne incognita and race 1 of Meloidogyne arenaria, which has caused a shift in population prevalence in Virginia tobacco fields toward other species and races. A number of cultivars now also possess the Rk2 gene for root-knot resistance. Experiments were conducted in 2013 to 2014 to examine whether possessing both Rk1 and Rk2 increases resistance to a variant of M. incognita race 3 compared to either gene alone. Greenhouse trials were arranged in a completely randomized design with Coker 371-Gold (C371G; susceptible), NC 95 and SC 72 (Rk1Rk1), T-15-1-1 (Rk2Rk2), and STNCB-2-28 and NOD 8 (Rk1Rk1 and Rk2Rk2). Each plant was inoculated with 5,000 root-knot nematode eggs; data were collected 60 d postinoculation. Percent galling and numbers of egg masses and eggs were counted, the latter being used to calculate the reproductive index on each host. Despite variability, entries with both Rk1 and Rk2 conferred greater resistance to a variant of M. incognita race 3 than plants with Rk1 or Rk2 alone. Entries with Rk1 alone were successful in reducing root galling and nematode reproduction compared to the susceptible control. Entry T-15-1-1 did not reduce galling compared to the susceptible control but often suppressed reproduction.     

Influence of micronization (fine grinding) of soya bean meal and fullfat soya bean on productive performance and digestive traits in young pigs

Two trials were conducted to test the effect of micronization (very fine grinding) of soya bean meal (SBM) and fullfat soya bean (FFSB) on productive performance and digestive traits of piglets. The experimental design was completely randomized with four treatments arranged factorially (SBM and FFSB, micronized and ground). The mean particle size (MPS) was 47 and 881 μm for the SBM and 41 and 778 μm for the FFSB, micronized and ground, respectively. In trial 1 growth traits from 23 to 45 days of age and the coefficient of total tract apparent digestibility (CTTAD) of dietary components at 33 and 45 days of age were assessed. In trial 2 the coefficient of ileal apparent digestibility (CIAD) of dietary components, the pH of the gastro intestinal tract (GIT) and the weight of digestive organs and spleen were measured at 45 days of age. From 23 to 33 days of age pigs fed SBM grew faster (253 g/d versus 213 g/day; P<0.05) and were more efficient (0.87 g/g versus 0.98 g/g; P<0.01) than pigs fed FFSB. For the entire experiment (23–45 days of age) pigs fed SBM tended to grow more (360 g/day versus 324 g/day) and to eat more feed (414 g/day versus 380 g/day) than pigs fed FFSB (P<0.10). The CTTAD of crude protein (0.798 g/kg versus 0.778 g/kg), organic matter (0.864 g/kg versus 0.839 g/kg) and gross energy (0.849 g/kg versus 0.830 g/kg) were higher for pigs fed SBM than for pigs fed FFSB (P<0.001). In addition, CIAD of organic matter (0.765 g/kg versus 0.705 g/kg) and gross energy (0.761 g/kg versus 0.711 g/kg) were higher for SBM than for FFSB diets (P<0.001). The pH of the different segments of the GIT was not affected by the protein source (P>0.10). Particle size did not affect any trait studied (P>0.10). The poor performance and digestibility of pigs fed FFSB as compared to pigs fed SBM might be related to the conditions applied during processing. It is concluded that pigs fed soya bean meal perform better than pigs fed FFSB and that micronization of the soya protein sources does not affect any trait studied.     

内蒙古多伦县土地沙漠化景观格局变化特征

利用景观分析软件Fragstats 3.3和内蒙古多伦县1960、1975、1987、1995、2000、2005年6期遥感影像解译结果,分析了1960—2005年间土地沙漠化景观格局变化.结果表明:1960—1995年间研究区土地沙漠化面积呈先增后减趋势,总沙漠化面积增加212.70km2,沙漠化斑块数先增多后减少,景观多样性和均匀性上升,轻度、中度、重度沙漠化斑块形状趋向简单;1995—2005年间研究区沙漠化斑块数大幅增加,景观多样性和均匀性下降,轻度、中度、重度沙漠化斑块形状趋向复杂;严重沙漠化斑块形状在1960年以后一直趋向复杂化.整个景观在研究期间表现为完整-破碎-完整-破碎的趋势,由轻度到严重沙漠化,其景观类型的破碎化程度逐渐降低.     

基于生理指标与籽粒产量关系的小麦品种抗冻性分析

以20个冬小麦品种为材料进行盆栽试验,对其在低温胁迫条件下功能叶超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性,丙二醛（MDA）、可溶性蛋白、可溶性糖含量以及籽粒产量、千粒重和籽粒形态性状进行测定.结果表明：拔节初期麦苗经-4 ℃低温胁迫后,不同品种冬小麦籽粒形态性状和产量性状均发生变化,绝大多数小麦品种籽粒长宽比、圆度和不育小穗数均增加,籽粒等效直径和面积及千粒重和籽粒产量均下降.通径分析表明,拔节初期低温处理后,功能叶SOD活性和可溶性糖含量是影响籽粒产量的主导因素,其中SOD活性对籽粒产量的直接影响较大,直接通径系数为-0.578.以籽粒产量下降的百分数作为小麦抗冻性评价的标准,可将20个小麦品种划分为3类：强抗冻类型的济麦19、济麦20、良星99、山农1135、山农8355、泰山23、泰山9818、汶农6号和烟农21,弱抗冻类型的临麦2号、潍麦8号、烟农19和淄麦12号,而其余7个品种属中度抗冻类型.苗期综合评价值（D值）与籽粒产量下降的百分数之间呈显著负相关(r=-0.512*),说明小麦苗期抗冻性强有利于获得较高的籽粒产量.苗期是小麦抗冻性鉴别选择的重要时期.     

Interaction Between Polyamine and Nitric Oxide Signaling in Adaptive Responses to Drought in Cucumber

The effect of polyamines (PAs) on nitric oxide (NO) generation was investigated in cucumber (Cucumis sativus cv. Dar) primary leaves using bio-imaging with an NO-selective fluorophor, DAF-2DA. Seedlings pretreated with PAs and subjected to water deficit showed early (after 5 h) and transient NO production. The amplitude of the response depended on the form of the applied polyamine. Spermine (1.0 mM) and spermidine (1.0 mM) induced higher NO-dependent fluorescence compared with putrescine (1.0 mM) and the control. The NO production was blocked by tungstate, an inhibitor of nitrate reductase, and partially by an inhibitor of nitric oxide synthase (NOS-like) enzymes. NO donor administration preceding drought had no effect on endogenous PA levels but was positively correlated with an alleviation of water deficit-induced membrane permeability and lipid peroxidation. Application of 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), a membrane-permeable NO scavenger, markedly reversed the NO donor effects. Similarly, pretreating seedlings with PAs resulted in lower ion leakage from the membrane and modified lipid peroxidation. The results indicate that NO may act downstream of PAs in cucumber seedlings under water stress.