湘中紫色页岩区芦竹生物量及养分分布规律研究

对湘中紫色页岩区芦竹的生物量和养分分布进行初步研究.结果表明:当年生芦竹杆(含叶)养分含量高于多年生,因此不宜砍伐利用当年生芦竹杆;根茎养分含量较高,是系统中良好的养分贮存库.一年生、二年生、五年生、八年生芦竹的生物量分别为293.00、5258.29、6746.87和480.86 kg.hm-2.     

Adoption of leaf color chart for nitrogen use efficiency in rice: Impact assessment of a farmer-participatory experiment in West Bengal,India

Unbalanced and excessive use of N-fertilizers causes environmental pollution, lodging of plants and increased pest pressure, in addition to increased cost to farmers from excessively applied fertilizers and pesticides. N application at the right time and in right amount is critical for healthy plant and environment. Rice leaf color intensity is directly related to leaf chlorophyll content and leaf nitrogen status. The concept for the use of leaf color as an indicator to apply N in rice was crystallized during 1990s. The International Rice Research Institute and the Philippine Rice Research Institute developed a leaf color chart (LCC) that helps guide farmers for real-time nitrogen management in rice farming. The technology is inexpensive, and easily affordable by most resource poor rice farmers. In 2003 we initiated a farmer-participatory research to validate real-time N management in rice by the use of LCC in West Bengal state of India. After 3 years of validation research, a survey was conducted to assess the adoption and impact of LCC. The survey was conducted in both intervention and adjacent control villages and data were collected from 20% farm households selected randomly. In this paper, we report findings of the study on the determinants of adoption of LCC, and its effect on fertilizer and pesticides use.     

黑河流域草地资源保护与建设

黑河流域除绿洲地区外有160万hm2的草地,进行草地分户、围栏封育、人工改良草地;牧户按地定畜、优化牧场、推广良种、改良畜群;按草定牧、实行休牧和轮牧;革新观念、子羔出栏、加速出栏周期、保障牧民增收等措施可保护草地资源,加速草地建设,繁荣牧区经济.     

西部退耕还林还草的序量问题探讨

针对目前退耕还林还革存在的严重盲动性和炒作性,认为西部生态建设要走"种树更要种草,还草先于还林,建立林草一体化产业"的发展模式,并从实现第三步战略目标对西部种草养畜发展畜牧业的要求和西部生态"先天性基因缺损"的规律等方面进行了详尽的论述,提出了退耕还林还革、建立林草一体化产业的对策措施.     

内蒙古赛罕乌拉国家级自然保护区陆生野生动物长期监测简报

开展生物多样性动态长期监测,了解生态系统结构与功能变化,探明生物多样性变化过程及影响因素是制定有效保护措施的重要基础。本研究在内蒙古赛罕乌拉国家级自然保护区开展10年野生动物多样性动态监测,新发现保护区分布哺乳动物7种、鸟类98种,内蒙古鸟类新纪录2种,内蒙古蛇类新纪录1种。但也未发现一些以往有记录的物种,需要进一步强化野生动物多样性监测,探明物种变化的原因。后续监测工作引入了非损伤采集动物粪样提取DNA技术,从而深入了解保护区野生动物种群长期稳定的遗传学和空间分布特征,为有效管理自然保护区珍稀野生动物提供科技支撑。     

竞技赛马的营养需要研究进展

马是一种独特的家畜,主要用途是娱乐或工作。长期以来,马的营养一直集中在提供足够数量和类型的营养素,以达到最大的运动状态。营养学家的目标是最大限度地发挥营养对运动的影响,因此,本文综述了关于赛马主要营养素的需求特点,为竞技赛马的饲养提供依据。     

基于B/S结构的家蚕育种与种性维持信息管理系统

对家蚕育种亲本及其新品种性状数据档案实行信息化管理,可在家蚕育种和品种的种性维持过程中自动实现完整的信息采集、计算、调用、选择等功能。开发了一个基于B/S结构的家蚕育种与种性维持信息管理系统,主要包括品种管理、计划任务管理、饲育信息管理、蚕茧信息管理、选种信息管理、选优信息管理等功能模块。选种信息管理模块的运行过程是通过电子天平称量蚕茧质量,然后根据计算模型自动进行数据信息处理与统计分析实施选择。用户可以方便地通过网络访问该系统,实现家蚕新品种选育及种性维持工作的自动化。     

A survey of mutations in the Cochliomyia hominivorax (Diptera: Calliphoridae) esterase E3 gene associated with organophosphate resistance and the molecular identification of mutant alleles

Cochliomyia hominivorax (Calliphoridae) is one of the most important myiasis-causing flies and is responsible for severe economic losses to the livestock industry throughout the Neotropical region. In Brazil, C. hominivorax has been controlled mainly with organophosphate (OP) insecticides, although the inappropriate use of these chemicals can result in the selection of resistant flies. Changes in carboxylesterase activity have been associated with OP insecticides in some arthopodan species. In this work, we isolated and characterized part of the E3 gene in C. hominivorax (ChE7), which contained the same substitutions responsible for the acquisition of OP hydrolase activity in Lucilia cuprina (Calliphoridae). Digestion of the polymerase chain reaction products with a restriction enzyme that specifically recognized the mutation site unambiguously differentiated wild and mutated esterase alleles. The PCR-RFLP assay therefore provided a fast, reliable DNA-based method for identifying C. hominivorax individuals with a mutation in the esterase gene. Further bioassays to determine the association of this mutation with OP resistance in C. hominivorax should allow the development of more effective strategies for managing this species.