科学家培育出“抗洪水稻”

一个国际研究小组宣布，他们发现了水稻中的“抗洪基因”，并利用这一基因培育出了长时间被洪水淹没却能存活的“抗洪水稻”。科学家表示，这个水稻新品种将给洪水多发地区的农户带来福音。水稻是全球30亿人口的主要粮食作物，它离不开丰沛的水灌溉。但多数现有水稻品种不能在“大水没顶”时长期存活，一般在水下不超过两三天就会死亡，因此水稻抗洪水的能力不佳。据统计，每年洪水给全世界水稻种植带来的经济损失高达10亿美元。     

一手抓整顿一手促繁荣--通化市整顿和规范地图市场秩序侧记

2002年至2003年．我国针对地图市场存在的混乱状况．开展了对地图市场的专项整顿。在此次声势浩大的工作中．通化市城乡建设委员会根据国家和省的要求．积极行动起来．及时制定实施方案。扎扎实实进行地图市场整顿和规范工作．较好地完成了整顿和规范地图市场秩序工作的各项任务．使通化市整顿和规范地图市场秩序取得显著成效。在治理．规范的同时．他们积极组织开发了多品种的地图产品．满足了社会各界及广大群众对合格地图产品的需求。促进了旅游等事业的发展。由于工作出色．2003年，通化市建委被评为吉林省整顿和规范地图市场秩序工作先进集体。     

丹玉13玉米在辽宁的布局

辽宁省具有历年夏雨集中的规律，而盛夏7～8月降水量在年降水量中占有很大比例。盛夏降水不单对汛期有较大影响，与农业生产引进良种也有很大关系。丹玉13玉米虽然具有很大增产优势，但是该品种对大斑病却没有高抗能力。盛夏降水较大时，对该品种生长发育不利，易发大斑病，不会有较高的产量，进而影响本品种的推广。据分析，当7、8月降水较少，相对湿度也适合时，对推广此品种较为有利。本着这一思路，在本省推广栽培中，考察本品种对气温、日照都较适宜，但对辽宁盛夏降水。     

不同甘蔗品种锤度与糖分的关系

使用大田实验数据和实验室数据建立了实验室锤度和田间锤度与甘蔗糖分关系的数学模型。统计分析表明，实验室锤度、田间锤度与糖分间均存在显著的线性关系，并且实验室锤度——糖分关系与大田锤度——糖分关系存在显著性(α=0．05)差异；而不同甘蔗品种间的田间锤度——糖分关系无显著性差异(α=0．05)。故不同的取样方法应使用不同的方程来估计甘蔗糖分；而不同甘蔗品种间田问锤度——糖分关系可用同一模型来描述。对三个供试甘蔗品种应用该模型进行实测验证，实测与预测值的相对误差均在7％以内。     

Species and plant community reorganization in the Trans-Mexican Volcanic Belt under climate change conditions

This study analyzes six vegetation communities in relation to current climatic parameters and eight climate change scenarios along an elevation gradient extending from 2,710 m to 4,210m in the Trans-Mexican Volcanic Belt. The projected movements of 25 plant species with the current restricted or wide altitudinal distributions were also modeled. To relate climatic parameters to the species and communities, a Precipitation/Temperature(P/T)index was used both for the current and the different climate-change scenarios. The temperatures are expected to increase by 1.1°C to 1.7°C by 2020 and by2°C to 3°C by 2050. A decrease of 4% to 13% in the annual precipitation is expected for the 2020 horizon,and a reduction between 3% and 20% is expected for2050. The reductions in water availability were projected for all altitude levels and plant communities.The most marked reduction was under the HADLEYA2 scenario, in which the lower limit of the altitudinal range increased from 2,710 to 3,310 m(2050 horizon)with reductions in the P/T index between 36% and39% compared to the current climate. Most plant species tended to shift their distribution from 200 to300 m upward in the 2020 temporal horizon scenarios. The Pinus hartwegii, Alnus jorullensis and Pinus montezumae communities would have a shorter altitudinal range as they move upward and merge with the remaining species at the higher altitudinal range. For the 2050 temporal horizon,30% of the species, primarily those from the higher altitudinal range, would disappear because their P/Tindex values would be above the limit of plant survival(4,210 m).     

Species richness,diversity and density of understory vegetation along disturbance gradients in the Himalayan conifer forest

We investigated whether species richness, diversity and density of understory herbaceous plants differed along logging(gap) and grazing(primarily by cattle) disturbance gradients, and sought to identify drivers of richness, diversity and density of understory vegetation of logged sites. A factorial experiment was conducted in the mixed conifer forest of Gidakom in Western Bhutan. Levels of the logging treatment included small(0.15 – 0.24 ha), medium(0.25 – 0.35 ha) and large(0.36 – 1.31 ha) gaps. The grazing treatment included grazed(primarily by cattle) and ungrazed(where herbivores were excluded by a fence) plots nested within each gap. Data were collected from 12 gaps(4 replicates at each level of logging) using the point intercept method. Shannon Weaver Diversity and Margalef's indices were used to estimate species diversity and describe species richness, respectively. Soil samples were analyzed for pH and nutrients. The interaction effect of logging and grazing was significant(p≤0.001) only on species diversity. Relative to ungrazed areas, species diversity was significantly higher(0.01≤p≤0.05) in medium grazed gaps. Under grazed conditions, soil P was negatively correlated with gap size and species diversity. While species diversity was positivelycorrelated(0.01≤p≤0.05) with soil N in grazed plots species richness was positively correlated(0.001≤p≤0.01) with soil N in ungrazed plots. Relative density of Yushania microphylla and Carex nubigena were higher under ungrazed conditions. Our study suggests that the combined effect of cattle grazing and logging results in higher species diversity of understory vegetation in medium and grazed gaps in mixed conifer forests of Bhutan,whereas increase or decrease in relative density of major species is determined primarily by the independent effects of grazing and logging. From management perspective, forest managers must refrain from creating large gaps to avoid loss of nutrients(mainly P and N), which may eventually affect tree regeneration. Managers intending to maintain understory vegetation diversity must consider the combined effects of grazing and logging, ensuring low to moderate grazing pressure.     

小麦品种对禾谷缢管蚜抗性的多目标评价及抗性因素分析

用多目标层次加权法评价了８个小麦品种对禾谷缢管蚜的综合抗性,结果表明,８个小麦品种的抗蚜性强弱依次为Ｗ６（４０）２、小偃六号、ＮＷＡＵ３４－９、陕１６７、陕８００７、８５（６７）２４、８１（２８）２８、８５（６７）１５。抗性因素的分析表明,品种感蚜值与游离氨基酸总量呈负相关,在１７种游离氨基酸中,感蚜值与赖按酸和精氨酸的含量显著负相关,而与总糖含量呈正相关。     

农用矿物对提高大豆产量及品质的贡献研究

黑龙江省是大豆主产区，大豆的产量和品质一直处于全国领先地位。农用矿产资源的开发与利用，可以为大豆的种植增添新的肥料品种，有助于黑龙江省绿色农业的发展。实现农业矿产资源的高效利用，对黑龙江省保持在全国的农业强省地位具有积极的促进作用。     

辽西地区高蛋白玉米气候适宜性研究

2004年4～9月,凌源市气象和农技部门合作开展了针对高蛋白玉米品种的气象条件试验,通过设不同小区、多重复试验和平行观测,综合多项指标筛选出适合当地气候条件下的优质玉米品种,初步得出了这些品种的生长发育特征特性和生育期气象指标。