Natural adjustment of population density of Larch casebearer (Coleophora dahurica)

Population increase of Larch casebcarer (C. dahurica) were controlled by comprehensive factors. Spring wind caused 27% of larvae on crown to fall down. Early and late frosts, larch caterpillar, sawfly and needle cast of larch could reduce the food quality and quantity of larch casebcarer and had indirect effects on population density. Birds, ants and spites were the main predators ofC. dahurica. The parasite complex comprisedPtermalidae, Eulophidae, Ichneumonidae andBraconidae. “Self-adjustment”, of population caused by “self-population density”, only runs effectively at a high larval density.     

新化合物F1050生物活性及作用方式研究

F10 50是由国家南方农药创制中心浙江基地与中科院上海有机化学研究所共同创制的含氟二苯胺类新化合物 ,室内生测结果表明 ,具有较高的杀虫、杀螨和杀菌活性 ,尤其对螨类生物活性更高 ,并对螨类各个虫态都有较好的防治效果。作用方式以触杀作用为主。     

Toxicological and biochemical characterizations of AChE in Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)

The toxicological and biochemical characteristics of acetylcholinesterases (AChE) in the resistant and susceptible strains (SS) of Liposcelis bostrychophila were investigated. The two resistant strains were the dichlorvos-resistant strain (DDVP-R) and the phosphine-resistant strain (PH₃-R) with resistance ratios of 22.36 and 4.51, respectively. Compared to their susceptible counterpart, the AChE activity per insect and the specific activity of AChE in DDVP-R and PH₃-R were significantly higher. There were also significant kinetic differences between DDVP-R and PH₃-R. The apparent Michaelis-Menten constant (K_m) for acetylthiocholine iodide (ATChI) was obviously lower in SS than that in PH₃-R, indicating a higher affinity to the substrate ATChI in the susceptible strains. The affinity for the substrate ATChI in DDVP-R and SS were not significantly different. The V_max value of the PH₃-R was significantly greater when compared to the V_max for the SS suggesting a possible over expression of AChE in this resistant strain. The inhibition of AChE to insecticide exposure in vitro revealed that all six insecticides were inhibitory for the extracted AChE’s. Based on the I₅₀ values, AChE of the SS were more sensitive to dichlorvos, paraoxon-ethyl, malaoxon and demeton-S-methyl than those of the two resistant strains. As for carbaryl and eserine, the PH₃-R suggested a significantly higher I₅₀s compared to the susceptible strain, while, no significant differences were found between SS and DDVP-R.     

芹菜叶斑病药剂防治试验

芹菜叶斑病（Cercospora apii Fres.）是宁夏芹菜上的主要病害之一,为了获得防治芹菜叶斑病的最佳药剂,笔者利用70 %安泰生等药剂对芹菜叶斑病的防治效果进行了试验,以期为芹菜生产提供参考.     

中国梨育种的回顾和展望

对我国梨育种工作进行了系统的回顾,包括梨的种质资源、引种、实生选种、芽变选种、辐射育种、杂交育种、遗传规律研究和生物技术研究等。我国梨的种质和品种资源丰富、栽培面积大,是世界上梨栽培面积最大、产量最多的国家。除了继续进行早熟梨的选育外,还要加强品质改良育种、加工用品种、矮化密植用品种、绿色食品用抗病等新品种的培育。探索用生物技术手段,如遗传标记和转基因技术,来改良梨的品质和抗逆性等性状。     

重复应用增产菌对青贮玉米的增产效果

增产菌对饲草、饲料在哲盟已连续应用４年,增产菌剂量为１５０～３００ｇ／ｈｍ２,产量提高１５．０７％～２１．６５％。１９９７年对青贮玉米重复应用增产菌３００～１６５０ｇ／ｈｍ２,收到了不同的效果,产量提高１７．２２％～３６．８７％。     

蝴蝶兰组培工厂化生产技术

 介绍了蝴蝶兰组培快繁技术及其工厂化生产技术。     

番茄多茸毛基因Womz的遗传表现及其利用价值

 按孟德尔质量性状遗传研究设计, 以普通番茄多茸毛品系LS1371 与普通品系强力62 配制的六世代遗传群体, 研究番茄多茸毛形态突变基因Wo^mz的遗传机理, 通过各世代的表现型和基因型关系的研究分析, 提出控制该多茸毛性状的Wo^mz基因为单基因不完全显性遗传。在实际育种中, 比较Wo^mz基因与Wo基因的避虫性表现, 表明Wo^mz基因在番茄抗虫育种中更有利用价值。     

鲜食加工兼用杏新品种‘冀光’

 ‘冀光’是采用有性杂交(‘串枝红’ב二红’) 育成的中晚熟鲜食加工兼用杏新品种, 具有成熟早、外观美、品质佳、加工性好、丰产性强等特点, 适合华北杏树适生区栽培。     

早熟、大果、优质桃新品种‘美硕’

 ‘美硕’是采用实生育种( 亲本‘京玉’) 育成的鲜食桃新品种, 具有成熟早、果实大、外观美、品质优、丰产性强等特点, 适合我国桃树适宜生态区栽培。