油茶林土壤微生物生态分布及土壤酶活性的研究

为了了解油茶林土壤肥力状况，我们对株洲地区油茶林地土壤微生物数量和土壤酶活性进行了研究。研究结果表明：根际土壤中的细菌数量明显大于非根际土壤，根际土壤酶的活性高于非根际土壤；新造幼林地土壤微生物数量较萌芽更新林地多，土壤酶的活性也以新造幼林地较萌雅量更新林地土壤高；低改林地土壤微生物数量较未低改林地多，土壤酶的活性也以低改林地高。     

水黄皮叶斑病的成因、严重性及杀菌剂防止

对孟加拉国4个苗圃(IFES、IFESCU、BFRI和ANC)内水黄皮叶斑病症状和严重性进行了调查,结果表明:IFESCU苗圃内叶斑病侵染率及致病指标最高、BFRI次之、ANC最低.与叶斑病相关联的组织从发病植株分离出来,被分离的真菌形成致病性.结果证实胶孢炭疽菌即为致病菌.观察了杧果炭疽病菌丝体生长抑制性并对杀菌剂(Bavistin, Cupravite and Dithane M-45) 有效性和浓度(0.05, 0.10, 0.50, 1.00, 1.50 和 2.00%)进行了鉴定.0.05% Bavistin和Cupravite潜伏8天后,菌丝体生长分别处于最低和最高水平.结果表明:Bavistin杀菌效果最好、Diathane M-45次之,Cupravite对菌丝体生长的抑制作用最低.图1表4参27.     

湖南油茶林不同经营措施对生物产量的影响

在湖南省桃源县理公镇泥头山60年生油茶林内，按不同经营措施，采用三阶抽样法，测定标准株的枝、干、叶、果的鲜重，并进行回归计算，研究在不同经营措施油茶林中各器官生物量分配、地上部分各器官的生长关系及垂直结构，结果为“三保”地油茶林果实生产率最高。     

油茶皂素抑菌效果研究

用溶剂法提取油茶枯饼中的皂素 ,以油茶皂素为材料对大肠杆菌 ,桔青霉 ,黑曲霉 ,金黄色葡萄球菌 ,和 117产朊假丝酵母进行了抑菌试验。结果表明 :均有抑制作用 ,其中对大肠杆菌和黑曲霉抑制作用较强 ,对金黄色葡萄球菌无抑制作用。对有效菌的最小抑制浓度在 0 .6 2 5 %以下     

The severity and cause of leaf spot disease of Pongamia pinnata L. and fungicidal control of the pathogen

A survey on the symptom and severity of the leaf spot disease of Pongamia pinnata L. was conducted in the nurseries of the Institute of Forestry and Environmental Sciences, University of Chittagong （IFESCU）, Bangladesh Forest Research Institute （BFRI） and Aronnak Nursery in Chittagong. The highest infection percentage and disease index were found in IFESCU nursery, followed by BFRI and the lowest was recorded in Aronnak nursery. The associated organism of leaf spot disease of P. pinnata was isolated from the diseased plant parts and the pathogenicity was established with the isolated fungus. Colletorichum gloeosprioides Penz was proved to be pathogenic. The inhibition of mycelial growth of C. gloeosporioides was observed and identified as suitable fungicides （Bavistin, Cupravite and Dithane M-45） and doses （0.05, 0.10, 0.50, 1.00, 1.50 and 2.00）. The lowest and highest mycelial growth were respectively found on Bavistin and on Cupravite at the concentration of 0.05 after 8th day of incubation. It indicates that out of the three tested fungicides, Bavistin showed most effective, followed by Diathane M-45, and Cupravite was ineffective for its very little inhibition on mycelial growth.     

Effect of forest vegetation on runoff and sediment production in sloping lands of Loess area

According to fixed-position data for 1985–2003 from nine runoff plots of Caijiachuan watershed which lies in Jixian County of Shanxi Province in Loess area, this paper studied the relationship between vegetation and runoff and sediment production in sloping lands in detail, which helps to provide scientific basis for vegetation re-construction and studies on environmental transformation of water and sediment in watersheds of Loess area. Although, many study results testify that forest vegetation has an important function in soil and water conservation and cutting runoff, the effect of vegetation on runoff and sediment transmission is complicated, and this needs to be studied in depth. The results of the paper showed the following. Firstly, the natural secondary forest performs better function of soil and water conservation than artificial Robinia pseudoacacia forest, and runoff and sediment produced in the former in individual rainfall were 65%–82% and 23%–92% of those produced in the latter. At the same time, better correlative relationship between runoff and sediment production and rainfall and rainfall intensity were testified by multiple regression, but the correlation decreased gradually with the increase of canopy density of forest. Secondly, the difference of runoff and sediment production in several land use types was very distinct, and the amount of runoff and sediment produced from Ostryopsis davidiana forest and natural secondary forest were the least, and runoff and sediment produced from in artificial Robinia pseudoacacia forest and Pinus tabulaeformis forest were 5-fold as much as those from O. davidiana forest. Besides, runoff and sediment produced in mixed planting of apple trees and crops were 16.14-fold and 2.96-fold than those of O. davidiana forest, respectively, but the amount decreased obviously after high-standard soil preparation in the case of the former. Thirdly, based on gray cognate analyses of factors affecting runoff and sediment production in sloping land, the factors of stand canopy density and herb and litter biomass were the most significant ones, whose gray incidence degree exceeded 0.6. Therefore, mixed forest with multi-layer stand structure and shrub forest should be developed in vegetation re-construction of Loess area, which will help to increase coverage and litter thickness in order to cut down the runoff and sediment dramatically in sloping land. __________ Translated from Chinese Journal of Applied Ecology, 2005, 16(9): 1,613–1,617 [译自: 应用生态学报, 2005, 16(9): 1,613–1,617]     

腾冲红花油茶优良单株选择

2012~2014年,根据相关选优标准,以冠幅、树高、地径、结果量和叶形等为指标,经过初选、复选、决选,选出腾冲花红油茶优良单株17株,其种子油不饱和脂肪酸和亚油酸含量达90%及8%的较高水平。对各单株、树高、地径、冠幅、果重等性状指标进行了阐述。     

基于彩色空间距离优化的秸秆覆盖率检测算法研究

秸秆覆盖率是保护性耕作重要的评价指标之一。针对田间秸秆形态各异、细碎秸秆难以识别的难题,基于机器视觉技术,提出了一种基于K-means和彩色空间距离灰度化方法相结合的田间秸秆覆盖率检测算法。采用彩色空间距离方法对秸秆图像进行预处理,基于K-means算法实现秸秆和土壤背景的分类识别,使用数学形态学腐蚀和膨胀方法对识别后的图像进行处理,降低细碎秸秆对覆盖率的影响,最后计算秸秆图像的覆盖率。2022年10月,通过田间试验对北京小汤山国家精准农业研究示范基地采集的220幅玉米秸秆图像进行了算法验证。试验结果表明,对低秸秆覆盖率(0～30%)图像,识别准确率达到90%;对中等秸秆覆盖率(30%～60%)图像,识别准确率达到88%;对高秸秆覆盖率(60%以上)图像,识别准确率达到86%;整体秸秆覆盖率分等定级准确度达到98.18%。本研究设计的基于K-means和彩色空间距离灰度化方法相结合的田间秸秆覆盖率检测算法为保护性耕作评价提供了快速检测方法和手段。     

汽车弯道自动转向照明系统的研究

汽车上安装的普通前照灯具有固定的照射范围,当汽车夜间转弯时,由于无法调节照明角度,常在弯道内侧出现"盲区",极大地威胁了驾驶员夜间的驾车安全。本文研究的汽车自动弯道照明系统,安装在货车、农用运输车上,根据夜间行驶道路的弯道情况,随时自动调整弯道照明的光束方向,减少弯道内侧出现的盲区,以便及时发现障碍物和行人,从而增强夜间驾驶的安全性。     

2种桑树病原真菌多重PCR检测方法的建立

目的 褐斑病与轮纹病是桑树Morus alba 的2种常见真菌性病害,危害严重,给生产上带来极大损失。本研究旨在快速准确地诊断2种病害的主要病原菌新褐斑壳丰孢Neophloeospora maculans与膝节霉Gonatophragmium triuniae。方法 基于多重PCR原理,针对2种病原菌的核糖体内转录间隔区(Internal transcribed spacer, ITS)序列设计多重PCR的特异性引物,优化多重PCR反应的条件,并通过对45份不同地区桑树褐斑病与轮纹病样本进行检测以验证所建立的多重PCR的可行性。结果 建立的多重PCR检测体系具有良好的可操作性,特异性良好,2种病原菌的DNA检测灵敏度分别达0.1 和1.0 pg/μL,通过对不同地区的田间收集的多份桑树病样进行检测,可以明显区分出不同地区2种病害病原菌的种类。结论 所建立的多重PCR技术可用于桑树褐斑病与轮纹病病原菌的快速检测,可为桑树真菌性病害的防控建立基础。