商品肉鸡非典型新城疫的防制

近年来,随着我国农村肉鸡养殖业的较快发展,养殖户对新城疫（ND）的免疫预防都非常重视,普遍进行了ND的免疫接种.因此,典型的ND已很难再见到,剖检时也很少再见到典型ND的特征性病变,给ND的诊断和防制带来了一定的难度,同时给农村养鸡户带来了很大的经济损失.     

Characteristics for Practical Use of Attenuated Isolate UA-Fukushima of <Emphasis Type="Italic">Tomato mosaic virus</Emphasis>

L₁₁A-Fukushima (L₁₁A-F) derived from attenuated isolate LuA of Tomato mosaic virus (ToMV) has the highest ability to cross protect against virulent ToMV among LuA and its derivatives and is stably inherited. Growth, yield, fruit quality and symptom attenuation of inoculated tomato plants did not differ significantly between L₁₁A-F and L₁₁A. The infectivity of progeny viruses in tomato infected with LuA-F was less than 4% of that with virulent ToMV. From these results, L₁₁A-F appears to possess the properties necessary for practical use. To manage L₁₁A-F strictly, a PCR-based assay to detect trace contamination of virulent ToMV in L₁₁A-F preparations was established. Received 10 June 2002/ Accepted in revised form 30 October 2002     

Effects of Latent Infection of Stock Plants and Abundance of Thrips on the Occurrence of <Emphasis Type="Italic">Tomato spotted wilt virus </Emphasis>in Chrysanthemum Fields

DAS-ELISA proved to be reliable enough to detect a latent infection by Tomato spotted wilt virus (TSWV) in asymptomatic stock plants of chrysanthemum. A high density of Frankliniella occidentalis, the predominant vector, in the presence of latently infected stock plants resulted in a high incidence of disease in the chrysanthemum production field. The incidence of disease was low when the vector thrips were not abundant in spite of the presence of latently infected stock plants. These results suggest that an infestation of the vector thrips causes severe secondary spread of TSWV originating from latently infected stock plants in chrysanthemum production fields. Received 27 July 2001/ Accepted in revised form 27 November 2001     

氟虫腈(锐劲特)对水稻害虫防治效果及增产效应

为了阐明新一代杀虫剂氟虫腈(锐劲特)对二化螟、三化螟、稻纵卷叶螟的防治效果及应用前景,进行了水稻盆栽试验、田间防效试验,并对施用锐劲特后水稻叶绿素含量、功能叶叶面积和产量进行了测定。结果表明,锐劲特施药后13天接虫的三化螟幼虫死亡率仍高达94.44％。在田间防效试验中,每公顷施用锐劲特80％WG有效成分24g防治二化螟,防止枯心效果达97.62％,防止白穗效果达94.44％,害虫死亡率达96.15％;每公顷施用锐劲特5％SC有效成分22.5g防治晚稻三化螟,保苗效果可达95.91％,害虫死亡率达99.04％;每公顷施用锐劲特5％SC有效成分30g防治稻纵卷叶螟,保叶效果达97.88％。叶绿素含量比对照增加32.4％;每公顷施用锐劲特80％WG有效成分36g时,功能叶叶面积增加16％～27.5％,并且杂交稻博优湛19比常规稻早糯3321和早熟早籼815对锐劲特更敏感。每公顷施用锐劲特5％SC有效成分22.5～37.5g时,水稻株高增加4.0～6.1cm,每稻丛穗数增加2.6％～31.18％,结实率提高19.43％～33.97％,水稻产量增加21.58％～28.19％。     

电流处理抑制甘薯丛枝病症状及提高茎尖培养成苗率

甘薯丛枝病在我国东南沿海主薯区流行多年,发病率高,是影响我国甘薯产量和品质的一个主要限制因子。其典型症状是植株叶小、褪绿、矮缩和侧枝丛生。甘薯丛枝病病原物是一种类菌质体(Mycoplasma-like organism,MLO),现在国际上统称植原体(Phytoplasma)。     

羊肚菌研究进展

综述了近年来羊肚菌营养成分、有效成分，培养技术，以及细胞学、生物化学和分子生物学等方面的研究进展。     

早熟春大白菜新品种三园春皇的选育

从北京、天津引进的大白菜品种中选育出两个自交不亲和系 90 2和 90 7,继而配制成春大白菜一代杂种三园春皇。该品种早熟 ,生长期 6 0～ 6 5d(天 ) ;一般 6 6 7m2 产量 40 0 0～ 6 0 0 0kg ,比对照鲁春白 1号增产16 % ;抗病毒病和霜霉病 ,对软腐病的抗性与对照相近 ;叶球橄榄形 ,质地脆嫩 ,品质优良。单球质量 2～ 2 .5kg     

七种寄主植物对烟粉虱生长发育、存活和增殖的影响

烟粉虱Bemisia tabaci(Gennadius)是一种世界性的经济作物重要害虫,近几年在我国南方及河北、山东、北京、天津等地已发展为主要害虫。国外对其生物型、生物学、种群动态和防治技术已有较多的研究,我国相关研究报道较少。作者研究25℃下烟粉虱在七种寄主植物上的生长发育、存活及增殖情况,试图为制定综合防治策略提供参考。     

Indole-3-acetic acid biosynthesis in <Emphasis Type="Italic">Aciculosporium take</Emphasis>, a causal agent of witches' broom of bamboo

 Aciculosporium take (Ascomycota; Clavicipitaceae) is a causal agent of witches' broom of bamboo plants. The symptoms of this disease are believed to be induced by plant hormones, particularly auxins. Indole-3-acetic acid (IAA) was identified in cultures of this fungus in an l-tryptophan-supplemented liquid medium. IAA production was confirmed on 30 isolates of A. take from various hosts and locations at levels up to 1 mg/l. The biosynthetic pathway of IAA in A. take culture was examined by analyzing intermediate products and by feeding experiments. The results showed that the indole-3-pyruvic acid pathway (l-tryptophan → indole-3-pyruvic acid → indole acetaldehyde → IAA) was the dominant pathway in A. take. Received: June 3, 2002 / Accepted: July 25, 2002