Multilocus PCR assay reveals high diversity of vegetative compatibility types in populations of Cryphonectria parasitica in Croatia

The ascomycete fungus Cryphonectria parasitica, causal agent of chestnut blight, is probably one of the best known invasive fungal pathogens in forests of Europe and North America. Mycovirus that reduces virulence of C. parasitica can be used as a biocontrol agent of the chestnut blight. However, anastomosis‐mediated virus transmission is limited by a vegetative (in)compatibility (vc) system involving at least six known diallelic vic genetic loci. This study looked at vegetative compatibility (vc) diversity in two populations of C. parasitica in Croatia. For that purpose, a PCR assay was validated and implemented using already known/published and newly designed primers for amplification of six known vic loci. The vc genotypes determined by PCR for 158 C. parasitica isolates investigated in this study were in complete agreement with the vc genotypes determined by pairwise co‐culturing of the same isolates, revealing the specificity and accuracy of the PCR‐based molecular vic genotyping assay. Twenty‐six unique vc genotypes were found among 158 isolates, and 19 vc types per population, which makes Croatian C. parasitica populations among the most diverse in Europe regarding the number of vc types and genetic diversity. Low values of multilocus linkage disequilibrium suggest sexual reproduction as a major contributor to high C. parasitica genetic diversity in studied populations.     

小麦籽粒营养物质和次生物质含量与其对玉米象抗性的关系

为明确生产栽培小麦品种对玉米象Sitophilus zeamais(Motschulsky)的抗性机制,采用选择性和非选择性试验法系统评估了9个小麦品种对玉米象的抗性,并分析了小麦籽粒营养物质和次生物质含量与其抗性的关系。结果显示,不同小麦品种对玉米象的抗性存在显著差异,其中陕麦139和西农88的不选择性和抗生性较弱,小偃22、周麦16和周麦11较强;玉米象成虫对西农165选择性最强,虫口数为152.00头,而卵至子代成虫发育历期最长,为35.06 d,子代成虫数、重量损失率和敏感系数均较低,分别为19.67头、5.37%和8.30;对周麦18选择性最差,敏感性居中。玉米象成虫对不同小麦品种的选择性与各物质含量,以及总酚、蛋白质含量与各抗性指标均无显著相关性,但阿魏酸含量与子代成虫数、敏感系数及重量损失率显著负相关;可溶性糖含量与子代成虫数、敏感系数及重量损失率显著正相关,与卵至子代成虫发育历期显著负相关。表明小麦品种对玉米象的抗生性与其籽粒中阿魏酸和可溶性糖含量相关,阿魏酸含量越高、可溶性糖含量越低,小麦对玉米象的抗性越强。     

Residues of diflubenzuron on horse chestnut (Aesculus hippocastanum) leaves and their efficacy against the horse chestnut leafminer, Cameraria ohridella

Residues of the insect growth regulator diflubenzuron were quantified on horse chestnut (Aesculus hippocastanum L.) leaves treated with a diflubenzuron 480 g litre^?1 SC, Dimilin. To analyse the samples, an analytical procedure was developed involving a simple extraction step followed by high‐performance liquid chromatography on an octadecyl‐modified silica column with methanol + 0.01 M ammonium acetate mobile phase. The results showed diflubenzuron to be highly stable on horse chestnut leaves; more than 4 months (127 days) after application, 38% (on average) of the insecticide still remained on/in the leaves. The data confirmed biological observations showing diflubenzuron's long‐term efficacy against the horse chestnut leafminer, Cameraria ohridella Deschka & Dimi?, which is the most important pest of the horse chestnut in Europe. The hypothesis of possible penetration of diflubenzuron into the leaf mass is explored and discussed. Copyright © 2006 Society of Chemical Industry     

产于浙江温岭的百合属一新变种——巨球百合

报道了发现于浙江温岭的百合属Lilium一新变种——巨球百合Lilium brownii F、E．Brown e Miellez var．giganteum G．Y．Li＆Z．H．Chen。本变种与原变种野百合Lilium brownii不同在于：鳞茎特大，直径10～12cm，鳞片100余枚，花冠淡黄色，外面带紫色；通常5～8朵。图1参10     

基于光致发光光谱的水稻品种快速鉴别研究

水稻是中国最重要的粮食作物之一,其种子品种鉴别是目前农业生产、作物育种和种子检验的重要问题。由于品种鉴别比较困难,每年因品种搞错和纯度差而造成的经济损失巨大。为此提出了一种应用光致发光光谱分析技术与化学计量学相结合的快速、无损鉴别稻谷品种的新方法。为了实现水稻品种的快速无损鉴别,采用北京卓立汉光仪器有限公司生产的光致发光光谱分析仪,对从长江大学农学院收集的5个不同品种的水稻共125个样本进行650~1000 nm波段光致发光光谱采集,获取了每个品种水稻各25个样本数据。将光谱数据经主成分分析压缩成数目较少的新变量（主成分）,其中前7个主成分能够解释99.696%的原始光谱信息。因此将前7个主成分作为BP神经网络的输入,不同水稻的品种值作为BP神经网络的输出,建立水稻品种的模式识别模型。样本被随机的分成包含100个样本的建模集和25个样本的预测集。结果表明,5次随机抽样建模的预测正确率均达到100%。同时也表明,主成分分析的数据压缩能力好,通过主成分分析和BP神经网络相结合建立模型进行不同品种水稻鉴别具有分析速度快、鉴别能力强的特点,为快速鉴别水稻品种提供了新的方法。     

褐飞虱在九个水稻品种上的生长发育和生命表参数

褐飞虱Nilaparvata lugens(Stl)是世界性水稻害虫,易暴发成灾,选育抗虫品种已成为控制褐飞虱的主要措施之一。为筛选出抗褐飞虱且适合我国黄淮流域种植的水稻品种,在温度为26±1℃、RH为(85±5)%和L∶D=16∶8的条件下,分别以9个河南省主栽水稻品种为食料,用生命表方法系统研究了不同水稻品种对褐飞虱实验种群生长发育、存活和繁殖的影响。褐飞虱在各水稻品种上的产卵量、孵化率、成虫寿命、卵发育历期、若虫发育历期、成虫发育历期等方面均存在显著差异,并且对褐飞虱的翅型分化有一定的影响。生命表参数综合评价表明,青两优916上的褐飞虱内禀增长率(rm)达0.56,净增值率(R0)和种群趋势指数(I)较高,分别达163.50和191.02,其次为特丰2053、冈优5330、Ⅱ优688、Ⅱ优2035、香丰1026、丰两优916、丰糯801和珍珠糯,说明青两优916最适合褐飞虱的生长发育和繁殖。     

品种、培养基质和接种量对马铃薯脱毒基础苗生长的影响

以马铃薯早熟品种大西洋、中熟品种克新1号、晚熟品种青薯168脱毒基础苗为试验材料,研究品种、培养基质和接种量对马铃薯脱毒基础苗苗鲜重、根鲜重、苗干重、根干重、叶片数、株高、茎粗、根长和根条数等性状指标的影响,培养14 d时,测定各性状指标。结果表明:三个品种的主要农艺性状均在液体培养基上表现为最佳,其平均单株鲜重、干重、株高、茎粗、节长和根条数分别为:159.4 mg、9.1 mg、7.3 cm、1.16 mm、1.4 cm、5.6条。在液体培养基上,降低了马铃薯工厂化生产成本,同时还可缩短马铃薯脱毒基础苗培养时间7~9 d。接种量对马铃薯单株根鲜重、苗干重、叶片数、株高、茎粗、根长有显著性影响(P<0.05);不同成熟期品种苗鲜重、根鲜重、根干重、叶片数、株高、茎粗、根长和根条数受品种影响显著(P<0.05);不同成熟期品种、不同接种密度处理对马铃薯单株根鲜重、苗干重、根干重、叶片数、株高、茎粗、根长影响有显著性交互作用(P<0.05);早熟品种大西洋,接种密度为0.67株/cm2时,中熟品种克新1号和晚熟品种青薯168接种密度为0.80株/cm2时,综合农艺性状表现最好。     

Testing variability in pathogenicity of Phytophthora cinnamomi

Forty eight isolates of Phytophthora cinnamomi from various host plants in France (35 isolates) and in other countries were tested for pathogenicity. Seedlings of chestnut, northern red oak, pine and eucalyptus were infected by soil contamination. Taproots, stems and bark strips of plants of chestnut and different oak species were inoculated with mycelium agar disks. Results of the different experiments were in good agreement. All isolates appeared pathogenic to all the different test species but with variable levels of virulence. Isolates with consistent low or high level of virulence, which could be used as standards in further studies, were identified. Interaction between P. cinnamomi isolates and host plant species was significant in terms of lesion lengths. These interactions could not be related to host from which P. cinnamomi was isolated. Consistent with this, in Quercus rubra, the isolate-provenance interaction was not significant. This feature is encouraging for provenance screening for resistance to P. cinnamomi in this species. The variation in virulence was not related to other isolate characteristics (mating type, electrophoretic type, age).