Antifungal activity of 1,3-disubstituted symmetrical and unsymmetrical thioureas

1,3-disubstituted aliphatic and aromatic symmetrical and unsymmetrical thioureas were synthesised by novel routes and the antifungal activities of these compounds against two plant pathogens, Pyricularia oryzae and Drechslera oryzae were studied in Czapek-Dox medium at four different concentrations using acetone as the control and the structure-activity relationship among the substituted thioureas is reported. © 1998 SCI.     

黄瓜病害控制中多菌灵和甲基硫菌灵的替代药剂评价

广泛使用的杀菌剂多菌灵和甲基硫菌灵对人类和环境生物存在较高的安全风险。从防治效果看，温室内黄瓜叶片上喷雾施用异菌脲（0．562kg·hm^-2）、嘧霉胺（0．450kg·hm^-2）和啶菌恶唑（0．070kg·hm^-2）对黄瓜灰霉病（Botrytiscinema）的控制效果均达到70％以上；喷雾施用氟硅唑（0．056kg·hm^-2）、嘧菌酯（0．141kg·hm^-2）、醚菌酯（0．141kg·hm^-2）和腈菌唑（0．028kg·hm^-2）对黄瓜白粉病（Sphaerotheca．fuliginea）也有较好的控制效果。从危害水平看，除百菌清外，根据其他几种备选农药相关参数计算得到的危害水平值均低于多菌灵和甲基硫菌灵。防效试验和危害水平对比相结合说明，在推荐剂量范围内，异菌脲、嘧霉胺、啶菌恶唑3种药剂可以代替多菌灵，而氟硅唑、嘧菌酯、醚菌酯和腈菌唑4种药剂可以代替甲基硫菌灵，分别用于防治黄瓜灰霉病和黄瓜白粉病，从而降低由这两种药剂使用而造成的潜在危害。     

嘧啶联吡唑甲酰胺类化合物的合成及除草活性

设计合成了一系列结构新颖的嘧啶联吡唑甲酰胺类化合物5a~5o,其结构均经过1H NM R和MS分析确证。初步生物活性测试结果表明:在有效成分150 g/hm2剂量下苗后茎叶喷雾处理时,化合物(R)-N-[1-(4-氯苯基)乙基]-3-二氟甲基-1-(4,6-二甲氧基嘧啶-2-基)-1H-吡唑-4-甲酰胺(5c)、N-[1-(4-氯苯基)乙基]-1-(4,6-二甲氧基嘧啶-2-基)-N-甲基-3-三氟甲基-1H-吡唑-4-甲酰胺(5i)和N-[1-(4-氯苯基)乙基]-1-(4,6-二甲氧基嘧啶-2-基)-3-三氟甲基-1H-吡唑-4-甲酰胺(5k)对繁缕Stellaria media的抑制率高达90%以上;而同样剂量下苗前土壤喷雾处理时,化合物N-[1-(4-氯苯基)乙基]-3-二氟甲基-1-(4,6-二甲氧基嘧啶-2-基)-1H-吡唑-4-甲酰胺(5b)和5c对繁缕的抑制率达100%。该类结构化合物有望作为除草先导化合物进行开发。     

Mitotic disruption by a novel pyrimidine herbicide, NS-245852, in oat (Avena sativa L.) roots

The effects of a novel pyrimidine herbicide, NS-245852 [2-chloro-6-fluorophenyl-4-(trifluoromethyl)thieno[2,3-d]pyrimidine-2-yl-ketone], on mitosis in oat ( Avena sativa L. cv. Zenshin) root tips were investigated by using light and immunofluorescence microscopy. The root growth was strongly inhibited at 10⁻⁷ mol L⁻¹ of NS-245852, and swollen root tips were induced at 5 × 10⁻⁸ mol L⁻¹. As observed by the use of light microscopy, the herbicide produced disrupted mitosis and large polynucleate cells in the meristematic root tissue. These symptoms were similar to those of mitotic disrupter herbicides. The immunofluorescence microscopy studies of the root tip cells treated for 30 min revealed that spindle fibers and the preprophase band were reduced, although kinetochore fibers and the phragmoplast were not affected. Kinetochore fibers remained as small fluorescence spots, and the phragmoplast disappeared after a 3 h treatment. No microtubule arrays were observed by a longer treatment (longer than 3 h). Among the microtubule arrays, spindle fibers and the preprophase band were found to be the most sensitive to the herbicide, whereas kinetochore fibers were the most resistant. The phragmoplast was intermediate. Thus, the primary action of NS-245852 is the inhibition of polymerization of tubulin into microtubules.     

利用染色体片段置换系定位水稻粒型QTL

水稻粒型是衡量稻米外观品质的重要指标之一,鉴定和定位水稻粒型QTL对开展水稻粒型分子育种具有重要意义.本研究以8个染色体片段置换系为材料,选用分布水稻12条染色体上的153个SSR标记检测染色体片段置换系的置换片段,采用代换作图法对控制水稻粒型的3个主效QTL进行定位.结果表明:153个SSR标记中有104个标记在亲本间具有多态性,多态率为68.0%;8个染色体片段置换系在第3和第5染色体分别有6个和2个置换片段,置换片段长度分别为14.8 cM、16.6 cM、 15.5 cM、18.9 cM、29.1 cM、35.0 cM、17.9 cM 和17.0 cM,平均长度为20.6 cM;8个置换片段上共鉴定出3个粒型QTL,控制粒长的qGL-3-1 和qGL-3-2分别被界定在水稻第3染色体RM5551与RM6832及RM6832与RM3513之间,遗传距离分别为14.8 cM和5.3 cM的范围内,控制粒宽的qGW-5被界定在水稻第5染色体RM267与RM169之间遗传距离约11.7 cM的范围内.利用染色体片段置换系能准确地定位水稻粒型QTL,qGL-3-1、qGL-3-2和qGW-5的鉴定和初步定位为其进一步精细定位及分子标记辅助选择奠定了基础.     

Agronomical and morphological differentiation among winter and spring triticales

A collection of 299 secondary hexaploid triticale cultivars and advanced breeding lines from 18 countries, which were considered a representative sample of the existing diversity, was evaluated for morphological and agronomical characters with autumn planting at Lleida, Spain, from 1988 to 1991. The entries were classified as having winter (84) or spring (215) growth habit and among this latter group were complete (73) or substituted (147) types according to CIMMYT's terminology. Winter and spring triticales were grouped by cluster and principal component analyses. Winter triticales were taller with longer growth cycles, longer spikes, and more spikelets per spike than spring types. At early stages they also had prostrate growth. Spring-substituted types were separated from complete material. As a group, spring-substituted triticales differed more from winter types than the spring complete genotypes, which showed intermediate characteristics. Complete types of spring habit had tendency to be taller, with longer spikes, more spikelets per spike and bigger and heavier grains than substituted triticales. Greater variation in morphological and agronomical parameters was detected among winter triticales followed by the complete-spring group.     

新型取代氨基(或芳氧)磺酰基苯氧丙酸酯的合成及其除草活性

由α-苯氧基丙酸酯出发,合成了取代氨基(或芳氧)磺酰基苯氧丙酸酯,并测定了它们的除草活性。所有的化合物均经1H NMR和元素分析确证,初步的生测结果表明上述化合物具有一定的除草活性。     

Yield and adaptation of hexaploid spring triticale

Summary Gains in yield and stability were analysed using grain yield data from the 8th to the 14th International Triticale Yield Nursery (ITYN) and differences in adaptation between complete and substituted triticales (X Triticosecale Wittmack) were examined. A trend of improving yield and adaptation was observed. As highly significant genotype × site interaction each year was not adequately described using regression analysis, yield stability was examined by ranking genotypes within sites and summarizing scores for individual genotypes across sites. Cluster analysis was used to study the relationships among sites and among genotypes. There was little evidence of sites grouping on a geographical basis. Grouping of genotypes showed a tendency for complete and substituted triticales to perform differently, suggesting that diversity for adaptation is maximized by utilizing both types in breeding.Progress for grain yield is compared with more spectacular gains in test weight and reasons for the different rates of improvement are postulated.Abbreviations CIMMYT International Maize & Wheat Improvement Centre - ITYN International Triticale Yield Nursery contribution from CIMMYT/Agriculture Canada (No. R-002)     

取代苯氧乙酸类化合物的超声合成及抑菌活性研究

采用超声波法在碱性条件下用取代苯酚与氯乙酸合成取代苯氧乙酸,并测试其抑菌活性．共合成了3个取代苯氧乙酸衍生物,即对氯苯氧乙酸,邻氯苯氧乙酸,对溴苯氧乙酸,用IR,^1 H NMR,UV及元素分析确证了其结构．同时选取大肠杆菌、沙门氏菌、枯草芽孢杆菌和金黄色葡萄球菌等四种细菌对所合成的取代苯氧乙酸类化合物测试其最小抑菌浓度（MIC）．抑茵活性表明：对氯苯氧乙酸和对溴苯氧乙酸的抑菌谱较广,而邻氯苯氧乙酸的抑菌谱较窄．     

六甲基六元瓜环与紫精衍生物作用体系及其除草活性研究

以紫精衍生物为研究对象,利用核磁共振技术、紫外吸收光谱和循环伏安法等方法,发现六甲基六元瓜环包结了紫精衍生物的烷基部分,形成2∶1比例的哑铃型包结配合物.结果表明,随着紫精衍生物烷基链的增长,紫精衍生物对杂草的除草活性依次减弱,且六甲基六元瓜环可增强紫精衍生物的除草活性.