气候变化对中国南方水稻生产的阶段性影响及适应性对策

根据GISSGCMTransientBRun的输出结果 ,结合中国南方稻区 15个样点近 4 0年的逐日气候资料 ,生成了每个样点在 2 0 10年、2 0 30年和 2 0 5 0年的气候变化情景 ;利用CERES Rice模型在基准气候 (196 0～ 1997年 )以及上述不同年份的气候变化情景下运行的结果 ,结合中国若干农业气候指标 ,分区评述了未来 10年、30年和 5 0年全球气候变化对不同稻作类型水稻生育期、产量、稻田蒸散量的阶段性影响 ,并分析了中国稻作制度可能发生的演进趋势。最后 ,在模拟试验的基础上 ,提出了若干适应气候变化的农业对策 ,包括调整品种布局、有条件地扩种双季稻、改善灌溉条件及培育和引进新品种等。该研究结果对国家及各级农业行政部门制定中远期农业规划和农业发展战略具有重要的参考价值     

谷子新品系抗除草剂试验

通过对抗除草剂阿特拉津谷子新品系DSB98-625SR喷施不同剂量的除草剂试验，结果表明各处理与对照比较具有一定的增产作用；而以2.25kg/hm^2除草效果与产量为最佳。目前我们巳进行杂交育种，预期选育出较为理想的抗除草剂阿特拉津的谷子新品系应用于生产。     

水杉基3层结构实木复合地板的制备及其导热声学性能的研究

将水杉木材用于基材制备实木复合地板并与市面常见的多层和3层结构实木复合地板的理化性能、导热及声学性能进行比较。结果表明：水杉基3层结构实木复合地板的含水率为10.7%,甲醛释放量为0.112 mg/m³,浸渍剥离指标符合国家标准要求。3种实木复合地板由于结构和树种组成不同,导热性有较大差异,水杉基3层结构实木复合地板导热系数为0.188 W/(m·K),在3种实木复合地板中最低,保温隔热效果最好。水杉基3层结构实木复合地板在0.2～2 kHz范围内11个频率条件下的吸声系数,均高于相同频率条件下其他2种实木复合地板。密度、含水率、漆膜厚度等均对产品吸声系数有影响。     

低钾胁迫对不同钾营养效应型大豆保护酶系统的影响

以四种钾营养效应型大豆品种(系)(铁丰31号、沈农6号、铁95068-5、GD1617)为试验材料,设置两个钾浓度处理,研究低钾胁迫对大豆整个生育期细胞保护酶系统的影响.结果表明:在低钾胁迫下,超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性均有不同程度的升高.SOD的活性高峰出现时期最早,CAT次之,POD出现最晚.从敏感型来看,耐性系数高的不敏感型品种(系)CAT与POD的活性差异明显高于耐性系数低的敏感型品种(系),SOD活性差异则不甚显著.由此,本文认为大豆钾营养敏感型间的差异可以通过保护酶系统活性差异得以表现.     

Plant diversity of secondary forests in response to anthropogenic disturbance levels in montane regions of northeastern China

The effects of anthropogenic disturbances on forest structure and plant diversity of secondary forest ecosystems were evaluated based on the classification by site factors in the montane regions of northeastern China. Forty-five sample plots containing 720 sub-plots of overstory species (8 m × 8 m), 1,440 quadrats of understory species (2 m × 2 m), and 1,440 quadrats of herbaceous layer species (1 m × 1 m) were clustered into five groups (G1, G2, G3, G4 and G5) by site variables with Hierarchical Cluster Analysis. Meanwhile, the disturbance levels corresponding to the five groups were determined according to the factors influencing human disturbances (D0-G2, D1-G1, D2-G3, D3-G5, and D4-G4). Species diversities of overstory, understory, herbaceous layer and overall species were evaluated using species number, Margalef index, Pielou index, Shannon–Wiener index, and Simpson index; and β-diversities (Whittaker index, Cody index). Basal area of stands exhibited a decreasing trend along the disturbance level due to a gradual increase in the extraction of timber by the human disturbances. The indices of species diversity suggested that overstory and understory species were distributed evenly among the groups or disturbance levels. There were no absolutely dominant tree species in the secondary forest ecosystems. The differences in site factors and the current disturbance intensities were not intense enough to lead to loose changes in overstory and understory species. The species diversity indices exhibited the maximum values at D3 (G5) for herbaceous layer species; this may suggest that the current disturbance intensities were intense enough to lead the changes of herbaceous layer species. Three rare and endangered species (Juglans mandshurica, Fraxinus mandshurica and Acanthopanax senticosus) were found within the secondary forests. These rare and endangered species appeared in each clustered group or disturbance level, which suggested that the current disturbance intensity in the study area was not strong enough to influence the distribution of rare and endangered species. The current disturbances in the secondary forests may not lead to a decrease in stability and complexity of the overstory and understory species, but the higher disturbance level may be intense enough to change the habitat fitness for the herbaceous species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized authors.     

新媒体时代科普工作原则--基于CAS理论视角

简述了新媒体和复杂自适应系统（CAS）理论的相关概念,辨析了传统科普和新媒体时代科普的不同,指出了新媒体时代的科普系统是CAS ,提出了用CAS理论指导新媒体时代科普工作的几点原则。     

紫苏甲羟戊酸-5-磷酸激酶基因PfPMK的克隆与表达分析

为了研究甲羟戊酸-5-磷酸激酶(PMK)在紫苏萜类物质生物合成代谢通路中的重要作用,对紫苏转录组数据进行分析,挖掘出紫苏PMK基因参考序列,采用基因克隆技术从紫苏中克隆了PMK基因,利用生物信息学和实时荧光定量PCR(qRT-PCR)的方法对紫苏PMK基因进行了分析。结果表明,紫苏PMK基因开放阅读框(ORF)全长为1 524 bp,编码507个氨基酸。生物信息学分析显示,PfPMK的分子质量为54.73 ku,等电点为5.20,为亲水蛋白;紫苏PfPMK氨基酸与SmPMK、SsPMK、SbPMK和PvPMK同源性较高,说明紫苏PfPMK蛋白在进化过程中保守性较强。亲缘关系分析显示,PfPMK与丹参和一串红的PMK亲缘关系很近,在线软件WoLF-PSORT预测PfPMK蛋白可能定位于质膜或内质网膜上。qRT-PCR结果表明,PfPMK基因在紫苏根、茎、叶中均有表达,在根中的表达量高于在叶和茎中的表达量;紫苏不同生长发育时期的qRT-PCR分析显示,PfPMK基因在9月中下旬表达量较高。首次从紫苏中克隆出PfPMK基因,生物信息学分析该基因属于甲羟戊酸-5-磷酸激酶基因,参与了紫苏萜类物...     

科技规划对中国农业技术现代化的 影响(1949—1985)

农业技术现代化是实现农业和整个国民经济长期快速、稳定发展的重要条件.从1949-1985年农业技术现代化起步、挫折和发展的历程可以看出,三次科技规划对农业科技发展重点项目的制定与实施产生重要作用.规划体制下农业技术现代化路径选择需要符合中国特定的资源禀赋,同时也需要制度创新的支持和加大投资力度.     

小麦产量性状与粒重性状的遗传分析

以小麦6044×01-35杂交后获得的重组自交系群体为试材,对其产量性状与粒重性状予以遗传分析。结果表明,重组自交系群体产量性状均呈正态分布,有不同程度的变异;单穗粒重与穗长和千粒重呈极显著正相关,与单株穗数、行总粒重呈极显著负相关,与株高呈显著负相关;广义遗传力较高的为株高、穗下节间长、穗长、单株粒重和单穗粒重;由主成分分析可知,对穗粒重贡献最大的是单株粒重、穗下节间长、穗长、单株穗数;通过逐步回归分析和通径分析,单株粒重对单穗粒重有促进作用,直接通径系数最大,单株穗数对单穗粒重的负效应最高。     

Lack of biocontrol capacity in a non-pathogenic mutant of <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> f. sp. <Emphasis Type="Italic">melonis</Emphasis>

The aim of this study was to assess the biocontrol capacity of rev157, a non-pathogenic mutant of a pathogenic strain of Fusarium oxysporum f. sp. melonis (Fom24). Inoculated in association with the virulent parental strain, the mutant rev157 did not protect the host plant (muskmelon) against infection by Fom24. Applied on flax, a non-host plant, the mutant rev157 was not able to protect it against its specific pathogen F. oxysporum f. sp. lini. On the contrary the parental strain Fom24 did protect flax as well as a soil-borne biocontrol strain (Fo47). Since the mutant rev157 was affected neither in its growth in vitro nor in its capacity to penetrate into the roots, it can be speculated that the mutation has affected traits responsible for interactions within the plant. In F. oxysporum the pair of strains Fom24/rev157 is a good candidate to identify genes involved in the biocontrol capacity of F. oxysporum and to test the hypothesis of a link between capacity to induce the disease and capacity to induce resistance in the plant.