草莓品种新秀“红颊”的特征特性及栽培技术

“红颊”系日本静岗县农业试验场以章姬为母本,さちのか为父本杂交选育而成。本院于1998年底从日本引入该品种,1999年意译定名为“红颊”。表现浅休眠、株型大、匍匐茎抽发能力较强、果大、果色红艳、口感好、硬度适中、耐贮运、抗白粉病、产量高、经济效益高。2006年1月通过了     

不同杀菌剂和诱导剂对草莓病害及产量的影响

为研究不同杀菌剂和免疫诱导剂对草莓主要病害和产量的影响,以草莓红颊品种为材料,采用双因素裂区试验设计,设诱导剂为主区,分清水对照(A0)和保康灵1号(A1)、仟禾福(A2)3种处理,设杀菌剂为副区,分清水对照(B0)、氢氧化铜(B1)、代森联(B2)、氯溴异氰尿酸(B3)、春雷霉素(B4)5种处理.结果表明:杀菌剂和诱...     

草莓炭疽病分生孢子离体快速繁殖技术探讨

为进一步了解草莓炭疽病菌的生物学特性,为其田间防控技术和抗性育种提供基础,研究了分离部位、接种材料、培养基、培养湿度、光照条件对菌丝体和分生孢子生长的影响。结果表明,以匍匐茎为接种材料,培养基中加氨苄青霉素50 μg·mL-1和链霉素50 μg·mL-1,能尽量减少草莓炭疽病菌分离时的污染率;以PDA或PSA为培养基,以孢子堆为接种材料,光照为252 lx,湿度为80%,是分生孢子产生的最佳条件。     

理化因子对茶尺蠖核型多角体病毒活性的影响

研究了pH、温度、紫外线和化学试剂处理对茶尺蠖核型多角体病毒活性的影响。结果表明,茶尺蠖核型多角体病毒在pH 7的环境中,活性最强,pH值升高或降低,茶尺蠖核型多角体病毒感染的茶尺蠖幼虫的死亡率都会下降;当水浴温度达80 ℃时,病毒几乎完全失活;紫外线处理32 h可明显降低病毒活性;在4种化学试剂中,01% CuSO4对病毒活力影响较小,经过乙醚和75%乙醇处理后的病毒活力有下降趋势。     

Engine crankshaft static strength analysis based on the finite element method

Focusing on the fracture issue of single cylinder engine crankshafts, a three dimensional solid model was built in CATIA. Pre treatments, such as plotting grids, were carried out through Hypermesh, and finite element analysis was done using MSC. Patran/Nastran. The results show that the fatigue safety coefficient cannot meet demand when nodular iron is the crankshaft material. This finding verifies the theoretical possibility of crankshaft fracture. A crankshaft using 40Cr theoretically would not fracture because the fatigue safety coefficient could meet the demand. Simulation correctness was verified by a 400 hour engine reliability test.     

大花惠兰组培苗中叶色突变体的获得与DNA鉴定

从大花惠兰的组培苗中获得了白色条纹和黄色条纹两种叶色突变体,突变发生的总频率约为0．12％。利用100条UBC随机引物将它们与对照进行了RAPD分析和对比。引物P17或P31可在对照和黄色条纹突变体间检测出多态性,黄色条纹突变体具有大小分别约为995bp或1320bp的多态性片段;而引物P84或P86则可在对照和白色条纹突变体问揭示出多态性,白色条纹突变体具有大小分别约为1120bp或1315bp的特异性条带。RAPD分析结果表明这两种突变体的基因组DNA都发生了变化。     

温度对三叶青组培苗SOD、MDA等指标的影响

用MS培养基上培养8 d的三叶青试管组培苗,进行不同温度的处理并培养一个继代周期后测定其鲜重、超氧化物歧化酶(SOD)、丙二醛(MDA)和可溶性蛋白等生理指标,以研究不同温度梯度处理对三叶青试管组培苗生长的影响,探究组培苗耐高温和低温逆境能力,为三叶青生产栽培实践提供技术参考依据。试验结果表明,30～35℃为三叶青试管组培苗最适宜生长温度,平均鲜重增加达到4.402 7～5.149 3 g,明显优于其它各处理,其SOD酶活性增强,MDA含量偏低,膜修复能力增强,可溶性蛋白含量增加,而40℃以上高温或10℃以下低温则不利于三叶青试管组培苗的生长。     

Spontaneous cure of domestic pigs experimentally infected by Trypanosoma brucei gambiense. Implications for the control of sleeping sickness

The existence of a pig reservoir for human African trypanosomosis (HAT) due to Trypanosoma brucei gambiense complicates the fight against this disease. This study, reports results obtained from pigs, which were inoculated with the blood of a person, suffering from HAT in Cameroon. The pigs were reared and kept in the shelter from all contact with Glossina, and monitored for 188 days. The seroconversion was checked by agglutination assays for trypanosomosis (CATT 1.3 and LATEX/T.b.gambiense). The parasitemia was measured by quantitative buffy coat method (QBC) and by polymerase chain reaction method (PCR). In addition, growth was recorded as well as blood counting and blood formulas. The results showed that the pigs were trypanotolerant and cure themselves in less than 6 months. It is concluded that sterilisation of this reservoir could be achieved by tsetse-control measures in 1 year. It confirms the strategy to complement screening and treatment of HAT with tsetse fly control measures.     

Porcine circovirus type 2 and associated diseases in Romania--short communication

Porcine circovirus type 2 (PCV2) has been demonstrated to be the causal agent for postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). This report describes the first detection of PCV2 and associated diseases in a Romanian swine herd located in Transylvania. The clinical signs, pathological and histopathological changes observed in affected pigs were similar to those previously described for PDNS and PMWS. Polymerase chain reaction and in situ hybridisation were used for the detection of PCV2 nucleic acids from tissues and serum samples. Complete PCV2 genomes of both PMWS and PDNS cases were sequenced and analysed, and by comparing them with each other no genomic differences could be detected. The sequence analysis showed that the Romanian PCV2 was closely related to PCV2 identified in France and in Hungary.     

白菜分子标记的研究进展

应用常规方法进行白菜的育种栽培已经取得了很大成功,但它能够利用的种质资源有限,近年来飞速发展的分子标记技术为进一步研究白菜类作物提供了新的途径。本文综述了RFLP、RAPD、SSR、AFLP等分子标记在白菜亲缘关系的分析鉴定、品种指纹图谱绘制、品种纯度检测和QTL定位等方面的研究进展。