冬小麦黄矮病抗性遗传研究初报

采用3×4不完全双列杂交,对抗黄矮病性母本和丰产性父本的组合效应进行了黄矮病抗性遗传研究.结果表明,(1) 亲本的一般配合力效应与特殊配合力效应正向相关,而一般配合力效应更具重要性;(2) 黄矮病抗性遗传符合加性- 显性遗传模型,以加性基因效应占绝对优势,遗传决定度高达97.68%,狭义遗传力为90.3% ,上下代遗传变异不大,可在早代进行直接选择.     

甘蓝型油菜菌核病抗(耐)性的遗传研究Ⅰ. 抗性遗传属性与配合力分析

以来自欧洲和中国的 6个抗 (耐 )、感病品种 (系 )为材料 ,用双列杂交和火柴棒接种法研究油菜菌核病抗性的遗传属性与配合力。结果表明 ,油菜菌核病抗性主要受核基因控制 ,但存在一定的母性效应 ,核基因作用方式表现为显性和加性基因作用。油菜菌核病抗性表现为部分显性 ,不同抗 (耐 )病品种的抗性显性程度存在差异。抗病品系 0 2 0的抗性相对显性率较高 ( 2 2 .0 8% ) ,Norin9的抗性相对显性率较低 ( 6.0 1 % )。亲本0 1 8的一般配合力效应值较高 ( 4.4 6) ,Cobra较低 ( -1 0 .54) ,Cobra× 0 1 8组合的特殊配合力较高并具有良好经济性状 ,为试验最优组合。     

玉米自交系对灰斑病抗性配合力及遗传参数分析

以6个灰斑病抗性不同的玉米自交系为亲本,按Griffing双列杂交试验设计方法Ⅱ组配15个杂交组合,对叶片病斑覆盖度进行配合力分析,并估算遗传参数。结果表明,6个自交系一般配合力(GCA)效应差别较大,齐319表现高抗;其次是鲁9801、B84和8112;9046和掖478表现感病。结合杂交组合实际表现与特殊配合力效应进行分析,齐319所组配的各组合抗性表现均较好;掖478与8112、9046、B84组配的各组合抗性差;由9046所组配的组合特殊配合力效应好。进一步对遗传参数的分析表明,该性状广义遗传力为64.49%,性状的遗传以加性效应为主,同时存在一定的非加性效应,性状表现受环境影响较大。     

玉米子粒含油量的遗传分析

用7个玉米自交系(5个高油自交系，2个普通自交系)作完全双列杂交，并对配合力、方差成份和遗传力进行分析。结果表明：自交系的一般配合力效应均达极显著水平；一般配合力效应与自交系的含油量呈极显著正相关，相关系数为0.98；含油量高的组合出现在一般配合力效应高的自交系中，一般配合力效应与特殊配合力效应无明显关系；自交系的含油量受环境影响较小，遗传方差占表型方差99%，遗传方差中，加性方差占88%，表明含油量的加性方差在遗传变异中起重要作用；含油量有很高的遗传力。     

甜玉米南方锈病抗性配合力及遗传特性分析

对甜玉米南方锈病抗性配合力及遗传特性进行分析,为抗病育种提供理论依据。从6个遗传差异较大的自交系,按照GriffingⅡ双列杂交设计,通过Photoshop CS5软件进行叶片病斑识别和病斑面积分割,分别得出叶片和病斑的像素值,以穗三叶病斑叶面积比作为鉴定指标,对南方锈病性状配合力及遗传参数进行分析。应用图像分析软件识别叶片病斑可相对精确地进行玉米南方锈病抗性的鉴定与量化。6个亲本一般配合力效应存在较大的差异,大小排序为：M114-1>M3-1>M4-1>M55-1>M119-1>M5-1,不同组合间的特殊配合力也存在显著差异,结合一般配合力及效应值与其他亲本杂交后的特殊配合力遗传变量,对自交系利用价值综合评价,表明自交系M119-1能将抗南方锈病的性状稳定地遗传给所有的组合,是较为理想的抗南方锈病自交系,在育种中应对其加以有效利用。南方锈病以非加性效应为主,甜玉米南方锈病广义遗传率为89.88%,狭义遗传率为6.70%,说明抗南方锈病性状受环境的影响较小,加性效应很低,应在高代选择。本研究克服了传统抗性鉴定只能获得分级间断型数据的缺点,利用图像分析软件,可以相对连续、精确、客观地统计玉米南方锈病抗性。并对南方锈病性状配合力及遗传参数进行分析,提高育种实践的选择效果与效率。     

龙生型花生青枯病抗性遗传研究──Ⅰ．抗性遗传属性与配合力分析

本文分析了几个龙生型抗青枯病花生品种的抗性遗传属性和配合力效应．结果表明，龙生型抗源抗性呈部分显性，存在加性和非加性的遗传效应，抗性的显性程度高于珍珠豆型和多粒型抗源，而且存在明显的细胞质效应。     

大麦白粉病抗性的遗传分析

为给大麦抗白粉病育种提供参考依据,以1个感白粉病、4个抗白粉病大麦品种为亲本,按Griffing的双列杂交法Ⅰ配制20个杂交组合,在田间自然条件下研究了大麦白粉病抗性的遗传特性。结果表明,大麦白粉病抗性在杂交组合间存在显著差异。5个亲本中,木石港3号和CM72的一般配合力较好,均表现为较大的负向效应,能极显著提高杂种后代抗白粉病能力;S096的一般配合力中等,也表现为负向效应,能显著地提高杂种后代抗白粉病能力,因而这三个品种在大麦抗白粉病育种中利用价值较高。大麦白粉病抗性遗传符合加性显性模型,同时受加性和显性效应的作用,且加性效应更重要。大麦白粉病抗性的狭义遗传力较低,早代选择不宜太严。     

籼型三系杂交稻恢复系制西与不同不育系的抗性淀粉含量的配合力分析

以籼型三系杂交稻恢复系制西与不同不育系配组,测定了亲本与不同组合的抗性淀粉含量;分析了亲本与组合抗性淀粉含量这一性状的配合力效应以及亲本抗性淀粉含量与配合力效应之间的相关性。结果表明:研究的4份亲本抗性淀粉含量的遗传特点是以加性效应为主。一般配合力效应值和亲本抗性淀粉含量显著相关,绝对系数为0.98。而特殊配合力效应平均值和亲本抗性淀粉含量相关性稍差,绝对系数为0.87。反交效应与亲本抗性淀粉含量不相关。以制西为父本配组的F1中,谷丰A/制西的特殊配合力效应值最大,并且呈超显性遗传。     

甘蔗实生苗净光合速率与经济性状配合力分析

甘蔗7个亲本按3×4不完全双列杂交(NCⅡ)遗传设计配制成12个组合,实生苗的净光合速率与经济性状的遗传方差、一般配合力(gca)和特殊配合力(sca)效应分析结果表明:株高和单茎重的遗传主要受母本加性基因效应控制,锤度的遗传主要受父本加性基因控制,而有效茎和假植期净光合速率的遗传主要受非加性基因效应所制约;CP72-1210作为母本,糖分配合力高,且能把高糖特性传递给后代,其后代综合性状较好。Zhan74-141为父本,产量性状的配合力大,其杂交后代表现高产;Gui73-167为父本,其杂交后代表现高糖。根据配合力总效应,综合表现好的组合有“ROC”1×Gui73-167,CP72-1210×Ya90-31,CP72-1210×Zhan74-141。     

烤烟淀粉含量的配合力与遗传分析

为了解烤烟烤后中部烟叶淀粉含量的遗传规律,选用K326、NC89、翠碧一号和红花大金元等4个品种,按完全双列杂交设计,采用Griffing方法Ⅰ进行配合力分析,并应用植物数量性状"主基因+多基因"混合遗传模型对K326×红花大金元组合P1、P2、F1和F2等4个世代群体进行遗传分析。结果表明:烤烟烤后中部叶淀粉含量的遗传主要受细胞核效应的影响,一般配合力方差和特殊配合力方差达极显著水平,一般配合力方差大于特殊配合力方差,翠碧一号的一般配合力表现为较高的正向效应,K326的一般配合力表现为较高的负向效应;K326×红花大金元组合烤后中部叶淀粉含量的遗传符合2对加性-显性-上位性主基因+加性-显性多基因模型(E-1),主基因遗传率(h_(mg)~2)为49.53%。     

中国小麦黄矮病的发生及综合防控研究进展

小麦黄矮病是中国小麦上的重要病害之一,由麦蚜持久性传播大麦黄矮病毒引起,具有间歇式流行的特点.为了综合运用小麦黄矮病各种防控措施.本文综述了小麦黄矮病在中国的发生及流行因素、蚜虫及小麦黄矮病的预测预报、抗病品种培育、化学防治、农业防治等方面的研究,并展望了未来的研究和防治策略,即寻找和利用多种抗黄矮病(BYDV)基因,培育具有优良农艺性状的多聚品种;综合运用各种防控措施进行蚜虫防治,切断BYDV的传播;筛选和研发病毒抑制剂,特别是对环境无污染的植物源和微生物源病毒抑制荆,减轻BYDV对小麦的危害.     

中国西北地区麦二叉蚜与禾谷缢管蚜对小麦黄矮病传毒能力的分析

为了研究中国西北地区蚜虫对小麦黄矮病的传毒能力,为西北地区防治小麦黄矮病提供参考依据,常温条件下在温室大棚用盆栽小麦做传毒试验,以接种不同数量有毒蚜的小麦苗作为处理,接无毒蚜的小麦苗作为对照.传毒3 d后,在接种麦苗上喷洒药剂彻底杀死蚜虫,充分发病后观察记录小麦黄矮病的发病情况.结果表明,中国西北地区小麦黄矮病的优势介体是麦二叉蚜,但禾谷缢管蚜的传毒能力比以前有所提高.关中地区禾谷缢管蚜的传毒力高于河西地区禾谷缢管蚜的传毒力;三个地区(关中地区、渭北地区、河西地区)麦二叉蚜的传毒力都较高,差别不明显.三个地区两种麦蚜的成蚜传毒力普遍高于其若蚜的传毒力.     

小麦黄矮病抗性基因及其鉴定研究进展

小麦黄矮病是由大麦黄矮病毒(BYDV)引起的小麦主要病害之一。本文综述了小麦BYDV的主要抗性基因及其鉴定方法、微克隆和微分离的研究进展，并对其形态学标记、生化标记、细胞学分析和分子标记鉴定方法的原理及应用作了比较分析。本文最后还提出了目前研究中存在的问题及其未来研究的方向。     

Insecticidal control of cereal aphids and its impact on the epidemiology of the barley yellow dwarf luteoviruses

Imidacloprid is a seed-applied nitroguanidine insecticide that has both contact and long-lasting systemic properties. Its direct effects on cereal aphid populations and indirect effects on barley yellow dwarf luteovirus (BYDV) incidence were examined in laboratory and field studies. Adult longevity and fecundity of three aphid species caged on various aged, imidacloprid-treated oat or wheat plants was reduced, although the quantitative efficacy of the compound differed among aphid species. The transmission efficiency of BYDV by aphids to imidacloprid-treated plants was lower, relative to nontreated plants, when plants were 10 days old, but similar to nontreated when plants were 24 days old. In three years of field trials using winter wheat and two years using spring oat, aphid populations were reduced significantly in imidacloprid-treated plots relative to nontreated plots. Although the number of alighting alate aphids did not differ significantly between imidacloprid-treated or nontreated plots, the number of apterous aphids remained significantly lower in the treated plots for the majority of the growing season. BYDV epidemics did not develop in spring oat in either of the two years. BYDV epidemics did develop in the fall in the emerging winter wheat crop. Rhopalosiphum maidis was the predominant aphid migrating into the 1991–1992 crop. The incidence of the BYDV-RMV serotype was three times higher in nontreated plots than in imidacloprid-treated plots. In the 1992–1993 and 1994–1995 seasons, R. maidis and R. padi were the predominant aphids migrating into the crop, although R. padi was the predominant colonizing aphid. The incidence of BYDV-RMV was similar in imidacloprid treated and nontreated plots in 1992–1993, but the incidence of the BYDV-PAV serotype was significantly less in the treated plots. In 1994–1995, the incidence of both BYDV-PAV and BYDV-RMV was higher in the nontreated plots than in the imidacloprid-treated plots. Imidacloprid offers several advantages both in terms of its long-lasting systemic activity and its mode of applicaiton. As a seed treatment, the amount of material applied is minimized, there is little waste and the environmental impacts are reduced. The effectiveness of the compound at reducing the fecundity or reproductive rate of several aphid species may be advantageous in controlling secondary spread of viruses. However, the contact properties of the compound, important in repelling aphids or preventing phloem feeding, may be short-lived, thus reducing its effectiveness in preventing primary spread of the virus into the crop, especially under high aphid and inoculum pressure.     

Simulating multiple pest damage in varying winter wheat production situations

The production situation–injury profile paradigm can be used as a framework to assess the harmfulness of multiple-pest complexes in a changing agriculture. A mechanistic simulation model for wheat, WHEATPEST, was developed to incorporate drivers of (i) variable production situations and (ii) their related injury profiles. The model simulates the harmful effects of pathogens, pests, and weeds in a simple, open, generic manner. Simulation drivers were derived from published reports, in particular through a meta-analysis of highly detailed farmers’ field surveys in the United Kingdom and the Netherlands. Preliminary analysis of the model's performances indicates that WHEATPEST conforms with available published reports in a range of production situations and injury profiles. While improvement on some components of the model are discussed, this work points at the need for the collection of cross-disciplinary, reasonably accurate, and standardised data at a system's level, and at the usefulness of modelling tools for basic research and policy.     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.