Can polycultural manipulation effectively control rice planthoppers in rice-based ecosystems?

Rice planthoppers (mainly Nilaparvata lugens (Stål) and Sogatella furcifera Horvath) are the most destructive rice pests throughout southeastern and eastern Asia. Planthopper feeding often causes “hopper burn” and reduces rice yields. Currently, insecticide use is the sole pest management option available to most Chinese farmers. Because pesticide use may have undesirable effects, environmentally sound and sustainable management alternatives are urgently needed. In a two-year field study at the Wuyishan Experimental Station of the Institute of Applied Ecology (IAE), Fujian Agriculture and Forestry University (FAFU), we evaluated the effects of polycultural manipulation on the abundance, sexual differentiation and wing dimorphism of rice planthoppers. The polycultural manipulation was arranged in mosaic patterns of paddy plots intercropped with non-paddy plots including chili pepper, ginger, maize and peanut plants. Monocultural fields of paddy plants were used as controls. Polycultural manipulation significantly reduced the abundance of total planthoppers and nymphs of N. lugens and S. furcifera. The number of overall planthoppers decreased on average by 49% and 55% in 2007 and 2008, respectively. However, polycultural manipulation had no impact on the proportions of female or macropterous planthoppers. The resource concentration and associational resistance hypotheses may explain these results. In polycultural fields, non-rice species may mask the chemical or visual attractants of rice, making them less apparent, and microhabitat differences in the levels of secondary compounds or in plant quality may also disrupt planthopper orientation.     

不同抗性大豆品种感染大豆花叶病毒后一些生理生化性状的变化

本文采用聚丙烯酰胺直板凝胶电泳等方法测定不同抗性大豆品种接种SMVI—1毒株后叶绿素含量及过氧化物酶同工酶谱及酶活性。结果表明,感病品种和中感品种比健林分别多2条和1条酶带。感病品种的过氧化物酶活性最强,是对照的14.5倍,其次是中感品种和抗病品种。感病品种叶绿素含量明显下降,仅为对照的18.57％,抗病品种为74.43％。     

西葫芦绵腐病、绵疫病、枯萎病、细菌性叶斑病、软腐病、花叶病和根霉腐烂病的识别与防治

介绍了西葫芦绵腐病、绵疫病、枯萎病、细菌性叶斑病、软腐病、花叶病和根霉腐烂病的危害症状、发病特点。提出防治这些病害应加强栽培管理,提高植株抗病能力,采用以铲除菌源和药剂保护为重点的综合防治措施。     

豇豆花叶病的防治措施

豇豆花叶病是一种全株显症的病害,是豇豆上最常见的病害之一,尤以夏秋高温干旱季节发生较多,严重的会大幅度减少产量和降低品质,给种植户造成不小的损失.本文分析了清溪镇豇豆花叶病的病因,发生规律及条件,提出了防治方法.     

侵染西瓜的烟草花叶病毒(TMV)的生物学种类鉴定

从西瓜上分离到病毒分离物XC -3 ,此分离物经人工接种可侵染茄科、葫芦科、苋科、藜科的 16种植物。钝化温度为 96℃ ,稀释限点 10 - 6 ～ 10 - 7,病毒汁液在室温下保存 5 5d以上仍有侵染活性 ,分离物粒体杆状 ,长 3 0 0nm ,宽 18nm ,提纯病毒的紫外线最高吸收峰在 2 60nm ,最小吸收峰在 2 5 0nm ,A2 80 /A2 6 0 =0 .86。经琼脂扩散反应、ELISA检测 ,分离物与TMV的抗血清均呈阳性反应 ,分离物XC -3可能为TMV的一个株系。经过ELISA检测该分离物在安徽省西瓜病样分离物中占 8.65 %。     

黄淮地区大豆花叶病毒株系的鉴定与分布

2001-2002年采集了黄淮地区四省28个县市的大豆病样591份，经初步繁殖鉴定、生物纯化及组织印迹检测，得到了50个SMV毒株, 采用王修强等筛选的10个鉴别寄主进行接种鉴定，检测到SC-3～SC-9等7个株系群，发现1个新的株系群SC-10。综合本单位1998－2002年的结果，黄淮地区(河南、山东、安徽北、江苏北) 在SC-1~SC-10中，除SC-2未发现外，9个株系群中，以SC-3和SC-7为主，分别占29.21% 和23.60%，SC-4和SC-8其次（10.11%、8.99%）。在各省分布上，河南省有7个株系群，SC-3、SC-4为主，SC-5、SC-7其次；山东省4个株系群，以SC-3为主，SC-8也占相当比重；皖北7个株系群，以SC-7和SC-9为主，其次SC-10；苏北8个株系群，以SC-3和SC-7为主，其次SC-8。按株系群看，SC-3、SC-4各省均有；SC-5、SC-6 、SC-7 在河南、皖北、苏北3地；SC-1、SC-8在河南、山东、苏北3地；SC-9只在皖北发现；SC-10在皖北、苏北2地发现；SC-2在黄淮未发现。     

非(弱)杀菌化学物质诱导烟草对病毒病(TMV)抗性的研究

研究了 12种非 (弱 )杀菌化学物质诱导烟草对烟草花叶病毒病 (TMV)抗性的效果 ,供试化学物质均能诱导烟草对 TMV的抗性。新复级差测验结果表明 ,不同非 (弱 )杀菌化学物质对烟草抗病毒病性具有不同的诱导作用 ,其中 ,水杨酸表现突出 ,平均防治效果为 5 0 .30 % ,灌根 +喷雾和灌根两种处理方法与喷雾处理差异极显著 ,但灌根 +喷雾处理和灌根处理之间差异未达到显著差异 ,低浓度处理诱导效果高于高浓度处理。     

Demographic response and life history of traditional forest resource tree species in a tropical mosaic landscape in Papua New Guinea

Disturbance is well known to play an important structuring role in rainforest succession and in maintaining overall diversity. However, the ecological responses arising from changes in land use such as traditional and modified shifting cultivation practices are less well known. The distribution and dynamics of plant populations may be affected by such changes in land use and often their responses are compounded by a lack of life history data. The life history traits and demographic parameters important to successional species responses to disturbance remain poorly understood beyond broad generalisations, particularly in rainforests outside of the Neotropics. We examined the life history and demography of five rainforest tree species in Papua New Guinea to investigate the effect of shifting cultivation practices on their population dynamics. The demographic parameters most successful for continued population growth were medium to high recruitment, low seedling mortality and high seedling abundance, relatively low growth rates (compared to many pioneer species) and moderate to high abundance in all life stages. Successful life history traits were high seed mass, moderate shade-tolerance and high cultural value. In accordance with their demographies and life histories, Pterocarpus indicus, Vitex cofassus and Artocarpus altilis were classified as early successional species, while Pometia pinnata and Canarium indicum were considered mid-successional. The results suggest that the earlier successional species do not necessarily have an advantage in disturbed environments; persistence is more likely to rely on the response of inherent demographic processes to external influences.     

The Empidemiology of Wheat Rosette Stunt in Hulunbeir District of Inner—Mongolia

The virus disease threatening wheat production in Hulunbeir District of Inner-Mongolia was identified as NCMV(Northern Cereal Mosaic Virus)or WRSV(Wheat Rosette Stunt Virus)by test of host range,transmission,virus particle and serology.The main vector for spreading the virus is planthopper,Laodelphax striatellus(Fallen),Which overwinters in the stubbles of wheat underground.The overwintered viruliferous nymphs emerged in late Pril is responsible for the early infection of the disease.Agropyron repens,an important perennial weed in cultivated regions,is also an important wild host of the virus and its vector.Severe loss is induced when wheat is infected before 3-leaf stage.The disease incidence could be predicted by a model with the population and viruliferous rate of overwintered vectors as independent variables.     

桑花叶卷叶病相关病毒外壳蛋白抗体的制备及利用

对桑花叶卷叶病相关病毒外壳蛋白抗原性较好的核心结构域进行克隆和序列多样性分析,结果表明50个克隆中有19个克隆株,CP16为优势株。构建重组表达载体pET-28a-SUMO-CP16,成功在大肠杆菌Rosetta中诱导表达该蛋白,利用亲和层析纯化重组蛋白并制备多克隆抗体。经Western杂交和ID-ELISA检测合格的抗体偶联Tosylactivated磁珠,用于桑花叶卷叶病相关病毒的纯化。经qPCR技术检测显示,纯化后的病毒样本中的背景RNA得到极大的减少,获得了高纯度的病毒样品。