甘肃中部麦区小麦条锈病菌越夏调查及品种抗性变异监测结果初报*

2007-2009年,对甘肃省中部麦区小麦条锈病越夏情况进行调查,结果发现：条锈病菌在定西、临夏等中部麦区海拔1 718~2 350 m地带自生麦苗上可顺利越夏,病田率和病叶率分别为63.0%~80.0%和1.05%~5.80%,其越夏菌源量比陇南更大,是当地秋苗发病的初侵染源;秋苗病情调查结果表明,中部麦区秋苗病田率和病叶率均高于同期陇南麦区;品种抗性监测结果发现,34个供试品种（系）在中部麦区和陇南麦区的抗条锈性表现基本一致,部分品种发病程度重于陇南麦区。表明甘肃省定西、临夏等中部麦区已成为陇南小麦条锈病越夏区的重要组成部分。文中还对中部麦区越夏菌源的影响、作用及品种抗性变异因素等进行了讨论。     

陇南地区小麦条锈病今后五年发生趋势预测

陇南地区小麦种植由于垂直分布悬殊,条锈病菌在该区内既能越冬又能越夏。不仅是我国条锈重要的越夏区之一,而且还是常发易变区。解放三十多年来该区小麦品种抗锈性的丧失大体经历了五次重大的变化,导致条锈病曾十一次大流行和中度流行。从三十多年来小麦条锈菌病的发生史看出,小麦品种的单一化和抗锈亲本的单一化是导致条锈病流行的主要因素。自1978年以后,全区普遍采取“以抗锈为前提、多抗源、多品种……”的良种推广原则和“在不同区域种植不同抗源品种”的品种布局原则,八年中,也有气候条件对条锈病发生十分有利的年份,但条锈病一直未造成较大的流行,据种子部门预测,今后随着种子工作的加强,     

陇东小麦条锈病发生流行的原因与持续控制对策

陇东不但是我国小麦条锈病传播的重要桥梁地带 ,而且有一定数量的条锈菌越夏、越冬菌源。当地菌源的存在和小麦品种的抗性丧失是小麦条锈病发生大流行的内因 ,春季降水量多是大流行的决定性因素。加强抗锈品种的选育及合理布局、实行生态防治是控制流行的核心。     

坚持综合治理有效控制小麦条锈病流行为害

天水市是全国小麦条锈病流行的核心区域。长期的防锈实践证明,必须走综合治理的路子,才能有效控制其流行为害。坚持生态治理,调整越夏区种植结构,压缩小麦种植面积,提高作物多样性,是控制小麦条锈病的根本途径;加大抗锈品种选育力度,提高品种整体抗锈水平,实行多品种、多抗源合理布局,是控制小麦条锈病的关键措施;加强预警体系建设,落实常规综防措施,是降低小麦条锈病灾害损失的有效手段。     

黔西部小麦条锈病菌越夏考察初报

调查了黔西部小麦条锈病菌越夏情况,结果表明:小麦条锈病菌在贵州西部赫章等地海拔1 700 m以上地区能够安全越夏,越夏面积约3.3万hm²,其越夏菌源能够与当地秋苗衔接,引起秋苗发病。     

云南省德宏州小麦条锈菌越夏调查初报

小麦条锈菌越夏菌源量直接影响着小麦条锈病的发生与流行。为了明确云南省德宏州是否是小麦条锈病菌的越夏菌源地,2010年和2011年在德宏州芒市江东乡海拔1 600、1 700、1 800、1 900m和2 000m处设置了小麦条锈病菌源观察圃,对观测圃中小麦品种和周围落粒自生麦苗上条锈病的发病情况进行调查,实时记录各观察点的温湿度。结果表明:(1)海拔2 000m的菌源观察圃能观测到小麦条锈菌越夏和越冬的情况,越冬菌源量和春季条锈病的发病情况存在相互影响的关系;(2)海拔1 900m及以上的地区最高日平均温度和旬平均温度均低于22℃,为小麦条锈菌的越夏区域;1 600~1 900m的区域内其最高日平均温度在22℃至25℃之间,最高旬平均温度均大于20℃小于23℃,符合小麦条锈菌越夏的理论温度要求;并且海拔1 900m及以上地区的菌源观察圃中可观察到小麦条锈菌越夏。以上结论证实了云南省德宏州芒市是小麦条锈菌的越夏菌源地之一。     

2004年平凉市小麦条锈病越夏区自生麦苗发病严重

甘肃平凉地处小麦条锈病病菌越夏、越冬的桥梁地带,是我国小麦条锈病菌的主要菌源地之一。越夏菌源量多寡,对该地乃至全国冬麦区秋季和来年春季发病程度影响很大。2004年在当地海拔1450m以上的条锈病越夏区自生麦苗上条锈病严重发生,发病范围之广和发病程度之重,在本市是罕见的     

402份国内外春小麦种质资源抗条锈性评价及分析

正小麦条锈病是影响小麦生产最重要的世界性病害之一,而青海省是我国小麦条锈菌Puccinia striiformis f.sp.tritici主要越夏流行区(姚强等,2014),每年拥有大量的小麦条锈病越夏菌源,且该省种植的春小麦主要为感病品种阿勃,给我国小麦条锈病越夏菌源区的治理带来了困难。国内学者在寻找春小麦优良抗条锈病基因方面做了大量的工作,然而     

陇南小麦条锈病的品种遗传多样性控制

为实现陇南小麦条锈病持续控制的目标,以遗传多样性为原则,组建以提高生产品种抗条锈基因丰富度、在锈菌越夏区和越冬区进行基因布局和持久抗性、慢条锈性、高温成株抗性等多种抗性利用为主要内容的控制技术体系。利用Yr10、Yr12、Yr13、Yr16、Yr26、YrC591等有效抗条锈基因的载体品种、Flinor 等持久抗性品种及中四等其它抗源材料育成一批综合性状优良、具有不同遗传背景的抗病品种和类型,其中2004年以来育成的10个品种产量性状有明显提高,在区域试验中较对照增产7.3%~28.9%。陇南小麦条锈病的控制已进入一个新阶段。     

陕西省植物病理学会举行年会讨论小麦条锈病和棉花黄枯萎病问题

陕西省植物病理学会于2月14日、15日在西北农学院举行年会。会上做了有关棉、麦、果树、蔬菜病害的专题报告,并以小麦锈病和棉花黄枯萎病为重点,展开讨论。总结12年来陕西省小麦条锈病研究的主要成就:1.基本明确了小麦条锈病菌的越夏、越冬和传播流行规律。2.选出一定数量的抗锈品种,提出应用多品种组合防治锈病的方向。3.对病菌生理小种变异和品种抗病性变异作了初步研究,认为碧蚂一号小麦丧失抗绣性     

Localization of metabolic sites of action of herbicides

Time- and concentration-course studies were conducted to determine the effect of thirteen herbicides on photosynthesis, respiration, RNA synthesis, protein synthesis, and lipid synthesis using isolated single leaf cells. Each herbicide was from a different chemical class. Appropriate ¹⁴C-substrates and product purification procedures were used for each process prior to liquid scintillation counting. The most sensitive metabolic site of inhibition was photosynthesis for atrazine, bromacil, dichlobenil, monuron, and paraquat; RNA synthesis for dalapon and dinoseb; protein synthesis for chlorpropham; and lipid synthesis for CDAA, chloramben, 2,4-D, EPTC, and trifluralin. However, with several herbicides, one or more process was almost as sensitive as the one mentioned above. All herbicides inhibited more than one process, and the most sensitive site of inhibition may not be the same process that was inhibited the greatest at the maximum concentration and maximum exposure time used. Therefore, a concept of metabolic sites of action, rather than a primary site of action, appears to be more meaningful for herbicides.     

福寿螺配偶个体大小选择性初步观察

通过野外观察与实验研究,掌握了福寿螺的婚配体制及其配偶选择性规律。福寿螺与多数低等动物一样,其婚配属于乱交制,无固定配偶;雌螺对与其交配的雄螺个体大小没有选择性,而雄螺对雌螺的个体大小有选择性,倾向于与较大个的雌螺交配。     

青稞种子带菌检测及杀菌剂消毒处理效果

为了研究青稞种子外部和内部携带真菌情况,比较不同杀菌剂对青稞种子的带菌消毒效果和对幼苗生长的影响,为青稞种子播前包衣处理和种传真菌病害防控提供依据,采用离体平皿法对云南迪庆‘云青1号’、‘云青2号’和‘短白青稞’3个主栽品种进行带菌检测,并对种子进行拌种或浸种处理测定6种杀菌剂对种子消毒效果,分析杀菌剂对种子发芽和幼苗生长的影响。结果表明:供试青稞种子表面携带的优势菌群为青霉(Penicilliumspp.)、镰刀菌(Fusariumspp.);种子内部寄藏的真菌主要为镰刀菌、核腔菌(Pyrenophoraspp.)、附球菌(Epicoccumspp.)、丝核菌(Rhizoctoniaspp.)、链格孢(Alternariaspp.)和木霉(Trichoderma spp.)。青稞不同品种的种子表面及内部携带的真菌种类差异较大。致病性测定表明,镰刀菌对种子萌发和幼苗生长影响最大,后期出现幼苗坏死现象。45%咪鲜胺EW、75%百菌清WP、50%福美双WP对青稞种子携带真菌均有显著抑制作用和消毒效果,50%福美双WP消毒效果最优,达100%;45%咪鲜胺EW、75%百菌清WP、50%福美双WP处理对青稞种子发芽和幼苗生长均无显著影响。     

厚朴病虫害种类的初步调查

采用标准地法和线路调查法,对湖北恩施市新塘乡双河厚朴基地的厚朴病虫害进行了系统调查,记录主要虫害13种,其中叶部害虫9种,枝干害虫2种,根部害虫2种。厚朴主要病害5种。藤壶蚧、厚朴枝角叶蜂和厚朴新丽斑蚜为湖北省首次报道,小绿叶蝉为厚朴新寄主记录种。同时记录了藤壶蚧的天敌6种,其中寄生小蜂2种,瓢虫4种;厚朴新丽斑蚜的天敌昆虫8种。对藤壶蚧、厚朴枝角叶蜂和厚朴苗木根腐病等重要病虫害的发生规律进行了初步调查,同时提出了防治建议。     

Effects of timing and method of application of Penicillium oxalicum on efficacy and duration of control of Fusarium wilt of tomato

The effects of timing and method of application of Penicillium oxalicum on the control of fusarium wilt of tomato were investigated. Application of P. oxalicum to tomato seedlings in seedbeds reduced disease caused by Fusarium oxysporum f.sp. lycopersici in a growth chamber by 45–49% and in glasshouse experiments by 22–69%. Disease suppression was maintained for 60–100 days after inoculation with the pathogen in the glasshouse. No disease reduction was observed in tomato plants where P. oxalicum was applied to seeds. Treatment with P. oxalicum did not affect the population of F. oxysporum f.sp. lycopersici in the rhizosphere.     

百合地下害虫主要种类调查及生物（源）农药筛选

调查了甘肃省临洮县为害百合的地下害虫种类, 并以主要发生为害种类为供试对象, 采用拌土法测定了几种生物（源）农药对主要害虫的室内毒力和致死中时。调查发现小云斑鳃金龟Polyphylla gracilicornis、棕色鳃金龟Holotrichia titanis为主要发生及为害种类, 不同时间发生种类存在差异, 9月份以小云斑鳃金龟幼虫发生为害为主, 发生量占地下害虫总数的66.16%, 平均种群密度为10.48头/m2, 10月份, 则以棕色鳃金龟幼虫发生为主, 发生量占地下害虫总数的96.86%, 平均种群密度为7.79头/m2, 主要取食百合根系和鳞茎, 造成根系数量减少, 鳞茎出现不规则褐色缺口或凹陷斑。药剂筛选结果表明, 1.8%阿维菌素乳油、200亿孢子/g球孢白僵菌粉剂对两种蛴螬均具有较高的杀虫活性和速效性, 药后7 d时, 校正死亡率在82.22%以上, 对小云斑鳃金龟幼虫和棕色鳃金龟幼虫的LC50分别为0.161、0.060 mg/g和5.558×107、0.362×107孢子/g, LT50分别为2.237 d（2.2 mg/g）、1.393 d（2.2 mg/g）和6.645 d（40.0×107孢子/g）、4.940 d（2.0×107孢子/g）, 这两种生物（源）农药对两种蛴螬的LC50和LT50值均略大于两种化学农药25%二嗪磷乳油、40%辛硫磷乳油处理的, 且对小云斑鳃金龟幼虫的杀虫活性均低于对棕色鳃金龟幼虫的杀虫活性, 致死中时则长于对棕色鳃金龟幼虫的致死中时。     

Systems of designation of pathotypes of plant pathogens12

A variety of systems of designation has evolved to name pathotypes of plant pathogens. The systems were evaluated to determine those best suited for particular purposes. Virulence and avirulence/virulence formulae of pathotypes have advantage over the use of consecutive numbers or letters given in chronological order of pathotype discovery. As soon as pathotype information exceeds a certain level of complexity, mathematical codes are most advantageous, in particular two codes, octal notation and coded triplets. A more universal adoption of the most appropriate codes is recommended to ease communication and comparisons of results.     

Mode of action of etoxazole

The mode of action of the 2,4-diphenyl-1,3-oxazoline acaricide/insecticide etoxazole has been argued to be moulting inhibition, but experimental results supporting this hypothesis are lacking. This study investigated the effect of etoxazole on chitin biosynthesis in the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae). Etoxazole induced moulting defects in fall armyworm larvae similar, if not identical, to those caused by benzoylphenylureas, a well-known class of insecticidal chitin biosynthesis inhibitors. Furthermore, in contrast to untreated larvae, the chitin content in the integuments of larvae several days after treatment did not differ from that in freshly ecdysed individuals, thus suggesting strong chitin biosynthesis inhibition in vivo. A more detailed investigation of the inhibitory potential by incubating cultured integument pieces from larvae of S. frugiperda with [14C]N-acetyl-D-glucosamine, a radiolabelled chitin precursor, revealed I50 values of 2.95 and 0.071 microM for etoxazole and triflumuron respectively. The incorporation of radiolabel into potassium hydroxide-resistant material was inhibited by etoxazole in a dose-dependent manner. Based on these results, it is concluded that the acaricidal and insecticidal mode of action of etoxazole is chitin biosynthesis inhibition.     

Mode of action of meturine

The effect of meturine on the light processes of photosynthesis was studied.Meturine is a herbicide for weed control in potato and cotton crops. It is a N-phenyl—N-hydroxy—N′-methylurea.The experiments were carried out on isolated pea and spinach chloroplasts.When examining photosystem I, reduced DPIP was used as an electron donor, whereas methyl-viologen served as an electron acceptor. When examining photosystem II, DPIP represented the electron acceptor.The obtained experimental results have pointed to the absence of the effect of meturine upon the photoreaction I.Unlike N-phenyl—N′, N′-dimethylureas (CMU, DCMU) meturine has been a very weak inhibitor of photoreaction II.The authors explain the photoreaction II inhibition of chloroplasts from plants treated with herbicidal doses of meturine by conversion of N-phenyl—N-hydroxy—N′-methylurea into Hill reaction inhibitor(s). N-Phenyl—N′-methylurea can be one of such meturine metabolites.Meturine herbicidal action is accounted for by meturine transformation into Hill reaction inhibitor(s) in the plant tissues.