Evaluation of Chinese Triticeae for resistance to Barley Yellow Dwarf Virus (BYDV)

Summary Barley Yellow Dwarf Virus (BYDV) is recognised as a major pathological constraint to cereal production in northern China and several widespread epidemics have been reported. The host range of BYDV includes not only cereals but many grasses. The indigenous Triticeae of northern China have likely been exposed to significant disease pressure from BYDV and therefore may be a potential source of BYDV resistance for cereal improvement. A wide range of Triticeae accessions collected over three expeditions in northern China were evaluated for resistance to BYDV. Seedlings were artificially inoculated and virus levels then assayed by ELISA. Resistance and immunity to BYDV were found to be widely distributed among the seven genera of Triticeae included in the screening. A high proportion of resistant and immune accessions was found in the genera Hordeum, Leymus, Elymus and Elytrigia. The wide range of reaction types to BYDV found within many species, and even between accessions of some species, indicates that natural selection for BYDV resistance may have been relatively recent in the Chinese Triticeae. A high proportion of resistance and/or immunity was found in Xinjiang compared to the general distribution. From the Chinese Triticeae tested the Leymus species may be the most appropriate material to initiate transfer of BYDV resistance to wheat.     

The Impacts of Irrational Exploitation and Utilization of Water Resources on Land Desertification and Its Countermeasures in the Arid Area of China

水是干旱区最为宝贵的自然资源之一，水量平衡在很大程度上影响着土地荒漠化过程．本文在荒漠化公约所作的荒漠化气候分区的基础上，对干旱区因水资源的不合理利用对土地荒漠化的影响如土壤盐渍化、植被退化和现有耕地的废弃加以综合分析，并据此提出了缓解这些影响的相应对策．     

评价全球气候变化对我国玉米生产的可能影响

利用我国玉米带１２个有代表性地点的作物、土壤和天气资料，验证了ＣＥＲＥＳ－Ｍａｉｚｅ在我国的适用性，确定了各地有代表性品种在模型中的遗传参数，还对模型进行了敏感性分析，之后，将ＣＥＲＥＳ－Ｍａｉｚｅ在各地当前气候以及在３中由平衡ＧＣＭｓ生成的气候变化情景下分别运行，通过分析与比较模拟结果，评价了当ＣＯ２倍增时，气候变化国各地玉米产量和灌溉需要量的可能影响，对Ｃ煌直接影响也做了考虑。还应用若干农业气     

新中国成立后木结构建筑的发展概况

从科学发展观的角度回顾了新中国成立后木结构建筑的发展概况。     

国家作物种质库长期贮藏的高粱种子生活力监测研究

【目的】了解国家作物种质库贮藏高粱种子的生活力状况，为国家作物种质库贮存高粱种子及其它作物种子生活力监测及更新方案的制定提供参考，达到长期安全保存种质资源的目的。【方法】对在国家作物种质库贮藏10年以上的3 300份高粱种子的生活力进行了监测，分析了不同起始发芽率和来自不同供种单位和年份种子的生活力变化，探讨了种子起始质量对贮存效果的影响。【结果】90%的种子在国家作物种质库贮存10年后的发芽率仍保持在入库最低标准85%以上，有33份（占被监测份数的1.00%）出现了明显下降，发芽率从85%以上下降至70%以下。从总体上看，低发芽率水平的种子份数增加，高发芽率水平的种子份数减少。来自不同供种单位和不同年份种子间的发芽率下降差异显著。【结论】在进行种子生活力监测时应首先监测生活力出现显著下降的送存单位提供的种子。另外，监测时应按顺序一份一份地检测，不能进行抽测，因即使是同一单位在同一年份送存的种子生活力变化范围非常大。种子在繁殖或更新时还应将其生长季节，特别是种子成熟和收获时候的气候条件进行记录。     

完善海洋伏季休渔制度的探讨——基于东海与浙江省的实践

海洋伏季休渔制度是目前我国最重要的海洋渔业资源保护管理制度,已经成为我国养护海洋生物资源、建设海洋生态文明、促进海洋渔业可持续发展的重要举措。通过对东海与浙江省伏季休渔制度历次完善情况进行梳理和比较,探讨完善伏季休渔制度。结果表明,东海伏季休渔制度调整的特点是延长休渔时间、增加休渔作业类型及细化休渔海域,浙江省的特点是规定了"定置作业"和"帆式张网作业"伏季休渔时间、保护区休禁渔、针对特定生物资源的休禁渔及捕捞辅助船纳入休禁渔范围;与东海伏季休渔制度内容相比,浙江省在保护区休渔、保护特定生物资源休渔和捕捞辅助船实施休禁渔管理等方面具有突出特点,并为从建设海洋生物保护区、延长休禁渔时间、管理捕捞辅助船等方面完善伏季休渔制度提供了有益的启示。在常规性伏季休渔期基础上,提出设立终年渔业禁捕区、特殊鱼类资源休禁渔期、临时性休禁渔期等多元化海洋休禁渔制度的建议。     

东北地区沼泽湿地空间分布格局及其影响因素分析

在分析东北地区沼泽湿地空间分布格局的基础上,利用逐步回归模型筛选出影响湿地空间分布的生态因子。研究结果表明,沼泽湿地的空间分布格局受气候、水文、地貌和人类活动等条件的制约,其中相对湿度和年平均降雨量有利于沼泽湿地的形成,而人口密度、坡度和气温不利于沼泽湿地的形成。     

东方蜜蜂研究——重新评价中国阿坝地理种群

杨冠煌等(1986)发表蜜蜂阿坝亚种Apis cerana abansis,其亚种学名并没有拉丁化,应为Apis cerana abaensis,因多种原因未得到认可,但形态测定和分子数据分析认可中国阿坝地理种群Aba cerana。笔者介绍蜜蜂种下分类时,测评了38个形态学指标的测量方法、阿坝地理种群研究历史和背景、青藏高原分化出阿坝地理种群的环境条件,以及该种群个体形态特征、生物学和分布;中国是世界东方蜜蜂多样性热点地区之一,提出了中国东方蜜蜂(工蜂)中华亚种Apis cerana cerana、印度亚种Apis cerana indica、海南地理种群Hainan cerana及阿坝地理种群Aba cerana的形态鉴定表,肯定中国东方蜜蜂的多样性;从中国蜂业生产实际出发,首次较好地解决了东方蜜蜂种和种下阶元(亚种和地理种群)的关系,提出保护东方蜜蜂阿坝地理种群的措施。     

北部湾多齿蛇鲻摄食习性及随生长发育的变化

2008年10月至2009年9月,对北部湾多齿蛇鲻逐月采样共749尾(实胃数408个),通过胃含物分析法研究其摄食习性及随生长发育的变化。结果表明,北部湾多齿蛇鲻捕食种类包括鱼类、头足类以及虾类等饵料生物,其中可鉴定出的鱼类种类有17种。以相对重要性指数百分比为指标,鱼类为最主要饵料(98.8%),其中优势饵料种类有蓝圆鲹(34.9%)、少鳞犀鳕(26.6%)、长颌棱鳀(4.30%)和条鲾(2.5%)。多齿蛇鲻摄食强度、饱满指数和成熟系数的月份差异十分显著,而以Brillouin指数表征的各月份营养多样性则无显著差异。一年中呈现3个产卵高峰期(3-4月、6月及11月),产卵期间摄食强度没有降低,仍然强烈索饵。随着体长的增长,北部湾多齿蛇鲻饵料生物个数变化较小,但平均单个饵料生物质量却明显增加。聚类分析表明,北部湾多齿蛇鲻各体长组间食物组成相近,其中136～255mm各体长组相似性系数均大于60%。     

Vertical distribution of jack mackerel Trachurus japonicus larvae in the southern part of the East China Sea

ABSTRACT:   The vertical distribution of jack mackerel Trachurus japonicus larvae was described based on discrete depth sampling using a MTD net system from the surface down to 100 m depth at 13 stations in the southern East China Sea between 27 February and 10 March 2002. Of the 20 782 fish larvae collected, T. japonicus larvae were most abundant, accounting for 37.0% of the total catch. The average abundance of the larvae was 419.0 individuals/10 m², with the average (± standard deviation [SD]) body length of 2.6 ± 0.3 mm (range 1.8–7.5 mm). The larvae were concentrated in the mixed layer, with peak densities in the 10–30 m layer. The average (±SD) weighted mean depth was 21.5 ± 7.8 m. There was no evidence of either diel or ontogenetic vertical migration for the early larvae of <5 mm. More than 90% of the T. japonicus larvae were collected in the water temperature ranging from 21 to 23°C. Vertical profiles of the larval densities and chlorophyll a coincided with each other, which might reflect the abundance of their main prey organisms, copepod nauplii and copepodites, since copepod production is known to be closely related with the chlorophyll a concentration.