柑桔锈螨（Phyllocoptura oleivora Ashmead）研究进展

柑桔锈螨是我国柑桔生产的重要害虫，在我国，一般每年有三个发生高峰期，造成对柑桔叶、果实的严重危害，在高温旱时危害尤为严重其发生适宜温度是２３～３２℃，最适温度是２５℃，光周期是Ｌ：Ｄ＝１２：１２，近年来已经对一些药剂如三氯杀螨醇产生了抗药性，就柑桔锈螨的发生规律、抗性和防治等进行了系统进行了叙述，并提出了综合防治措施。     

Genome-wide Association Study on Abdominal Fat Weight in Jinghai Yellow Chicken

The study was conducted to reveal the genetic basis of abdominal fat weight trait and scan molecular markers which could be used to improve the abdominal fat weight.The abdominal fat weight of female Jinghai Yellow chicken in core group were measured after being slaughtered.Genome-wide association study was carried out using specific-locus amplified fragment sequencing technology to detect SNPs associated with abdominal fat weight.Finally, five SNPs that associated with abdominal fat weight and reached suggestive genome-wide significance (P<1.1×10^-5) were found, and four of them (rs18144674, rs18144680, rs12246236 and rs12257795) reached chromosome significance level.Three SNPs (rs18144674, rs18144680 and rs19745739) located in a 1.6 Mb area of chromosome 2, and two SNPs (rs12246236 and rs12257795) located in a 12 kb area of chromosome 14.Genes in the candidate regions with 0.1 Mb windows were screened.Finally, eleven candidate genes of VIM, TRDMT1, AXIN1, PDIA2, ARHGDIG, gga-mir-1763, gga-mir-1564, CLCN7, ECL1, DNASE1 and SDOS were obtained.The molecular function and biological processes were analyzed using GO database.The results showed that those genes might be candidate genes affecting abdominal fat weight in Jinghai Yellow chicken.     

三北防护林新无性系-美青杂种系列引进与苗期选择

１９９８年春从中国林科院的实验点甘肃临夏回族自治州林科所引入北方型美洲黑杨（Ｐ．ｄｅｌｔｏｉｄｅｓ）×青杨（Ｐ．ｃａｔｈａｙａｎａ）杂种无性系　１３７个,扦插在内蒙奈曼旗兴隆沼林场二分场。１９９８年秋选出　１３个无性系,加入我地区新近确定的推广无性系──白城　４１作对照,１９９９年建无性系测试圃,２０００年春平茬,２０００年秋对这　１３个无性系生长量和抗性的调查与评价,以白城　４１为对照,初步选择出　１０个无性系,高生长较对照大　３０％以上的有　４个,２０％以上　５个;径生长大　５０％的　３个,３０％以上　２个,２０％以上　４个;所有无性系的抗锈病情况都好于对照。为丰富三北地区营造杨树农田防护林品种和改善三北地区杨树品种单一的问题有望选出新无性系。     

宁夏黄灌区三倍体毛白杨无性系苗期生长规律研究

对三倍体毛白杨无性系苗期生长发育过程及其生长规律进行了初步研究,并对苗期高生长与气候因子间关系进行了灰色关联分析。结果表明,三倍体毛白杨无性系生长发育具有明显的阶段性,生长进程呈现慢-快-慢的规律,并存在明显的速生期。     

菊花白锈病菌冬孢子萌发的生物学特性

菊花(Dendranthema × grandiflorum(Ramat) Kitam.)是中国传统名花,其花色丰富,花型各异,深受人们的喜爱.同时菊花也是世界四大切花之一,在国际花卉贸易中占有重要的经济地位.     

陕西黄河湿地保护与管理

黄河湿地是攸关黄河的健康生命,设立自然保护区是湿地资源得到保护与恢复的重要措施和有效途径。本文从陕西黄河湿地自然保护区的管理现状入手,分析了湿地资源保护与管理方面存在的关键问题,并提出了解决这些问题的主要对策。     

Response of slash pine planted on mounds in central and southwestern Louisiana

On two silt loam flatwoods in Louisiana, use of mounds as planting sites for slash pine (Pinus elliottii Engelm. var. elliottii) was shown to be more effective than planting without mounds (untreated control) after six growing seasons in the field. Mounds formed were of two sizes: low mounds made of 550 dm³ of soil and high mounds made of 1,000 dm³ of soil. One site was in central Louisiana and had two drainage classes: a somewhat poorly drained Caddo-Messer complex and a poorly drained Caddo soil. On both drainage classes, pine survival was not affected by treatment, but the incidence of fusiform rust galls on the main stem (caused by Cronartium quercuum (Berk.) Miyabe ex Shirai f. sp. fusiforme Burdsall and Snow) was greater on trees planted on mounds. The second site was a poorly drained Caddo soil in southwestern Louisiana. At this site, there were fewer surviving pines on controls than on mounds, but the incidence of rust galls was not affected by treatment. At both sites, pines were taller and had a greater mean diameter at breast height on mounds than on controls. Mound size did not influence tree size at either site.     

Activities of some Brazilian plants against larvae of the mosquito Aedes aegypti

The insecticidal activities of extracts and oils of seventeen medicinal plants of Brazil have been determined using an Aedes aegypti larvicidal bioassay. Oils from Anacardium occidentalis, Copaifera langsdorffii, Carapa guianensis, Cymbopogon winterianus and Ageratum conyzoides showed high activities with LC50 values of 14.5, 41, 57, 98 and 148 microg/l, respectively. The most active ethanolic extract tested was that from the stem of Annona glabra which presented an LC50 value of 27 microg/l. The potential application of cashew nut oil, an industrial by-product with low commercial value, in the control of the vector of dengue and yellow fever, may be proposed.     

黄河三角洲不同造林模式下土壤盐分和养分的变化特征

研究黄河三角洲重盐碱地5年生白刺林和新淤地上18年生不同类型林分土壤盐分和养分的变化规律。结果表明：白刺造林后显著地促进了土壤脱盐，明显地提高了土壤肥力；新淤地上植树造林能有效抑制土壤返盐，培肥地力；不同类型林分防止土壤次生盐渍化的效果没有差异，杨树、刺槐行间混交林提高土壤肥力的效果最好。     

黄河故道沙地杨树人工林不同间作方式的比较

The orthogonal experiment of different factors in 6-year-old poplar stands,including intereropping crops, appli-cation rate of fertilizer, and planting density of forest tree etc., was carried out in the sandland of the Yellow River original course. The results indicated that doing intereropping, enlarging the row spacing and prolonging the time of intereropping were the effective ways by which the needs of forest tree for nutrients could be applied, and the level of forest land produc-tivity could be increased. Meanwhile, the optimum intercropping way of poplar plantations at different ages was gound, which was useful for the site of tne present experiment.