羊草种群各类地下芽的发生、输出与地上植株的形成、维持动态

羊草地下芽库中各类型芽及所形成子株和母株的季节动态变化研究结果表明,当年返青母株是由上一年母株形成的80%的分蘖芽与分蘖芽子株,15%的根茎顶芽与根茎顶芽子株,以及5%根茎节芽和根茎节芽子株组成的,分蘖芽与分蘖芽子株是返青母株的主体。随着返青母株的生长,根茎顶芽是在5月20日早于分蘖芽和根茎节芽1个月发生,并首先呈水平生长方式远离母株,占据生态位;在6月20日水平根茎顶芽开始向地面弯曲,输出子株的同时,分蘖芽和根茎节芽开始形成,并输出子株。羊草母株以产生低比例根茎芽和高比例分蘖芽的扩展和丛生联合生长方式,以年内和年间的芽、子株、母株之间的不断循环,年复一年地维持着种群的无性繁殖机制。高降水年份可显著地增加地下芽库各类型芽数量,从而使地上子株和母株密度增加。     

遗传与环境在生物进化中的关系

本文讨论了在生物进化的过程中遗传与环境的关系及遗传物质的范围和生物可塑性的问题。遗传物质的变异是进化的内因，环境对遗传物质的变异起到诱发与筛选的作用，进化后的生物对环境又有反作用。     

An insight into population structure and gene flow within pure‐bred cats

Investigation of genetic structure on the basis of pedigree information requires indicators adapted to the specific context of the populations studied. On the basis of pedigree‐based estimates of diversity, we analysed genetic diversity, mating practices and gene flow among eight cat populations raised in France, five of them being single breeds and three consisting of breed groups with varieties that may interbreed. When computed on the basis of coancestry rate, effective population sizes ranged from 127 to 1406, while the contribution of founders from other breeds ranged from 0.7 to 16.4%. In the five breeds, F_IS ranged between 0.96 and 1.83%, with this result being related to mating practices such as close inbreeding (on average 5% of individuals being inbred within two generations). Within the three groups of varieties studied, F_IT ranged from 1.59 to 3%, while values were estimated between 0.04 and 0.91%, which was linked to various amounts of gene exchanges between subpopulations at the parental level. The results indicate that cat breeds constitute populations submitted to low selection intensity, contrasting with relatively high individual inbreeding level caused by close inbreeding practices.     

稻田青蛙种群动态及其作用评价

文中根据稻田青蛙种群密度消长调查和蛙胃解剖内容物的分析,评价了稻田青蛙对主要水稻害虫的控制效果。     

Markers, old and new, for examining Phytophthora infestans diversity

Late blight, caused by Phytophthora infestans , is an ongoing threat to potato and tomato crop production worldwide and considerable fundamental and applied research is conducted with the long-term aim of improved disease control. Understanding the mechanisms, processes and rates of P. infestans evolution is an important factor in predicting the effectiveness and durability of new management practices. A range of phenotypic and genotypic tests has been applied to achieve this goal, but each has limitations and new methods are sought. Recent progress in P. infestans genomics is providing the raw data for such methods and new high-throughput codominant biomolecular markers are currently being developed that have tremendous potential in the study of P. infestans population biology, epidemiology, ecology, genetics and evolution. This paper reviews some key applications, recommends some changes in approach and reports on the status and potential of new and existing methods for probing P. infestans genetic diversity.     

德宏局辖区边境口岸10年监测实蝇的结果与分析

利用德宏边境口岸10年的实蝇监测数据,从实蝇种类、种群数量和结构动态变化方面分析实蝇发生发展情况。结果如下:(1)10年间德宏地区共监测鉴定出13种实蝇,其中种群数量最多的是桔小实蝇、瓜实蝇和南瓜实蝇;(2)3种主要实蝇10年来发生数量呈上升态势,2009年增速最快,1年监测到的实蝇占10年总量的28.1%;(3)桔小实蝇已经成为德宏地区最大的优势种群,到2009年,它在3种主要实蝇中已占79.0%的绝对多数,增速也最快。     

基于县域单元的中国人粮关系及其变化研究

以基于县域尺度的1980年、1990年、2000年的统计资料为基础,采用人口粮食匹配曲线、基尼系数等指标,分析计算中国县域尺度的人口粮食关系,揭示中国县域人-粮关系及其演变规律,旨在为统筹解决国家粮食安全问题提供科学依据。研究结果表明：1）1980-2000年我国人口粮食匹配不均衡程度越来越高,一方面说明我国粮食生产集...     

杂交稻稻瘟菌致病菌系的组成及其变化

对四川省大面积主栽杂交稻组合汕优６３、汕优２号上的稻瘟病菌进行生理小种测定的结果表明，致病菌系由多个生理小种群组成，其中以ＺＢ、ＺＣ群小种为主。用不同生理小种的菌株接种汕优２号和汕优６３的结果表明：ＺＢ群小种对汕优２号的致病频率最高，为１００％，而不同生理小种群对汕优６３的致病频率无显著差异，平均为７５％。致使这两个杂交稻组合丧失抗性的菌株来自四川省发病多年的常规稻、雄性不育系和早熟杂交稻组合。四     

大突肩瓢虫生物学及田间种群消长研究

大突肩瓢虫Synonycha grandis(Thunberg）在云南开远1年发生4代，以成虫在蔗茎老叶鞘内越冬。日均温26.6-27.8℃下，卵期3－4天，幼虫期9－12天，预肾期1天，肾期4－5天，成虫产卵前期20－25天，1个世代历期37－46天；日均温24.5-25.5℃下，卵期5－9天，幼虫期14－21天，预肾期1－2天，蛹期5－8天，成虫产卵前期25－30天，1个世代历期45－55天。（第4代）（越冬代）各虫态历期延长，全代历期长达250余天。成虫、幼虫均捕食甘蔗绵蚜。大突肩瓢虫田间种群:6妆开始在蔗田出现，8－10月种群数量明显增长，11月间形成高峰，12月开始越冬。     

稻田蜘蛛混合种群空间分布的动态研究

稻田蜘蛛混合种群的空间分布在水稻的不同发育期存在差异。其空间分布主要由稻田蜘蛛本身的扩散程度及生殖 ,游猎型和定居型数量的多寡 ,主要目标害虫的数量及其分布 ,栖息环境的变化及其耕作方式和稻田蜘蛛的种群密度及其种间竞争程度决定。