白僵菌在松毛虫体上宿存侵染的电镜扫描观察

通过扫描电子显微镜,观察了几种人工的或自然的环境下白僵菌在马尾松毛虫体上的宿存与侵染过程,描述了分生孢子的萌发和菌丝形成中的形态变化,讨论了致病效果与环境的关系,对林间应用提出了建议。结果表明：在２５℃和９５％的温湿度条件下,分生孢子萌发较快,萌发率和侵入率较高;白僵病的发生需要８５％以上的相对湿度,这是自然环境中防治效果的制约因子;在松毛虫每年发生２～３代的我国林区,冬季放菌做法不宜提倡,６月份放菌更为适宜。     

球孢白僵菌继代培养中菌落局变现象及环境影响因素的研究

球孢白僵菌[Beauveria bassiana(Bals.)Vuill.]野生型多孢株以及从其上分离的单孢株在不同培养基、光照、温度和湿度条件下继代培养,结果显示:无沦是多孢株还是单孢株,在传代中均发生显著的菌落局变,并产生形态各异的分离子,多表现为菌苔瘠薄或气生菌丝徒长,肉眼可见产孢量减少;尤其是单孢株菌落局变产生的分离子往往伴随着棕黄色或红棕色色素的分泌。培养基、温度、湿度和光照等环境因素对菌落局变产生具明显诱导作用。以SDAY培养基、偏低的温湿度和全光照条件下产生局变频率较低。大批量生产中以麦麸作原料较适宜。提出了菌落局变发生的几种可能的遗传机制。     

The action of prostaglandin E2 and F1α on myocardial ischaemia-infarction arrhythmias in the dog

Prostaglandin E₂ and F_1α infusions have been tested for their ability to reduce the arrhythmias associated with occlusion of the left descending coronary artery in the anaesthetised dog. At 1 μg/kg/min both PGs reduced the incidence of premature ventricular contractions occurring during 25-min occlusions, while not reducing the incidence of ventricular fibrillation occurring on occlusion release. When infused for 5-min periods at 1 to 16 μg/kg/min, neither PGE₂ nor PGF_1α effectively reduced the frequency of ventricular arrhythmias occurring 24 hr after a permanent coronary occlusion.     

缓释单萜类挥发物对落叶松毛虫行为及落叶松主要防御蛋白的影响

单萜类植物挥发物能够影响昆虫行为,为了延长其作用时间并初步测定特定单一的单萜类挥发物是否为生物间的信号物质,选取落叶松挥发物α-蒎烯、月桂烯和莰烯,进行缓释处理后施用于兴安落叶松(Larix gmelinii)苗木并进行生测。将3种挥发物倒入缓释瓶中,挂于2年生落叶松苗木中下部;以用3种挥发物直接喷施落叶松苗为对照。通过室内Y形管嗅觉仪和室外苗木罩笼产卵试验,测定不同处理的落叶松苗对落叶松毛虫(Dendrolimus superans)雌成虫产卵寄主选择行为的影响。测定落叶松针叶内与抗虫相关的几种主要防御蛋白的活力。Y管嗅觉仪测定结果显示,用α-蒎烯和月桂烯喷施及缓释处理的落叶松对雌成虫有显著引诱作用;缓释处理的效果可持续5d;施用莰烯有显著驱避作用,缓释处理的效果可持续4d。室外笼罩试验结果表明,在分别施用α-蒎烯或月桂烯的树苗上,落叶松毛虫雌虫产卵量显著高于对照,缓释处理的效果可持续3d;施用莰烯的树苗上,落叶松毛虫雌虫产卵量显著低于对照,缓释处理的效果可持续3d。表明挥发物装于缓释瓶内与挥发物具有相同的作用效果,并可以有效延长挥发物的作用时间。各处理落叶松针叶内POD、CAT、PAL、PPO、CI和TI的活性均无显著变化,说明这3种单萜类挥发物不是兴安落叶松的预警信号物质,单一施用不能系统诱导增强落叶松的抗虫性,只起到落叶松毛虫行为干扰剂的作用。     

Mark—Recapture Accurately Estimates Census for Tuatara,a Burrowing Reptile

Abstract: Estimates of population size are necessary for effective management of threatened and endangered species, but accurate estimation is often difficult when species are cryptic. We evaluated effectiveness of mark–recapture techniques using the Lincoln–Peterson estimator for predicting true census size of a population of tuatara (Sphenodon punctatus), a burrowing reptile that is a conservation priority in New Zealand. We found that Lincoln–Peterson estimates (NŇ = 85) were accurate for predicting the census size (N = 87) after only a 3-day mark–recapture survey. We recommend this method as a cost-effective way to accurately estimate population size for isolated, inaccessible tuatara populations, because it requires limited personnel, expertise, and time, and has low environmental impact on fragile sites.     

湖北江汉稻区优质香稻上二化螟的为害特性

研究了二化螟Chilo suppressalis(Walker)对优质香稻鄂香1号和武香988及优质常规中稻鄂中5号的田间为害特性。结果显示,1代二化螟危害造成的枯心苗数优质香稻略低于优质常规中稻。2代二化螟危害造成的枯孕穗和白穗优质香稻鄂香1号低于常规中稻,平均每15丛7.91株。田间剥查发现优质香稻中4~5龄2代二化螟所占百分比高于常规中稻,武香988中2代二化螟蛹所占比例高于常规中稻,达46.51%。3代二化螟量优质香稻低于常规中稻。结果说明香稻受二化螟的危害集中在2代,因而香稻二化螟的防治应注意消灭1代老熟幼虫和2代幼虫。     

Molecular characterisation of ABC transporter type FtsE and FtsX proteins of Mycobacterium tuberculosis

Elicitation of drug resistance and various survival strategies inside host macrophages have been the hallmarks of Mycobacterium tuberculosis as a successful pathogen. ATP Binding Cassette (ABC) transporter type proteins are known to be involved in the efflux of drugs in bacterial and mammalian systems. FtsE, an ABC transporter type protein, in association with the integral membrane protein FtsX, is involved in the assembly of potassium ion transport proteins and probably of cell division proteins as well, both of which being relevant to tubercle bacillus. In this study, we cloned ftsE gene of M. tuberculosis, overexpressed and purified. The recombinant MtFtsE-6xHis protein and the native MtFtsE protein were found localized on the membrane of E. coli and M. tuberculosis cells, respectively. MtFtsE-6xHis protein showed ATP binding in vitro, for which the K42 residue in the Walker A motif was found essential. While MtFtsE-6xHis protein could partially complement growth defect of E. coli ftsE temperature-sensitive strain MFT1181, co-expression of MtFtsE and MtFtsX efficiently complemented the growth defect, indicating that the MtFtsE and MtFtsX proteins might be performing an associated function. MtFtsE and MtFtsX-6xHis proteins were found to exist as a complex on the membrane of E. coli cells co-expressing the two proteins.     

我国林业重大害虫松毛虫的灾害研究进展

我国松毛虫种类丰富,已报道27种,其中6种频繁暴发,年危害松林面积达200万hm2以上、经济损失数亿元。松毛虫灾害研究可以为综合治理松毛虫提供重要的理论依据与相关技术。近年来,我国在影响松毛虫种群发生的关键性因子分析、性信息素的研究与开发利用、松树挥发性物质的成分鉴定及其对寄生蜂或寄生蝇的定位作用、卫星遥感监测技术等方面的研究取得了较大进步,但缺少系统性的归纳总结。为此,文章就近些年来我国在松毛虫灾害机制与暴发机理研究、治理现状与技术措施等方面进行综述,展望今后我国松毛虫治理研究工作的重要方向和趋势。     

De novo 3q22.1 q24 deletion associated with multiple congenital anomalies,growth retardation and intellectual disability

We describe a boy with a de novo deletion of 15.67 Mb spanning 3q22.1q24. He has bilateral micropthalmia, ptosis, cleft palate, global developmental delay and brain, skeletal and cardiac abnormalities. In addition, he has bilateral inguinal hernia and his right kidney is absent. We compare his phenotype with seven other patients with overlapping and molecularly defined interstitial 3q deletions. This patient has some phenotypic features that are not shared by the other patients. More cases with smaller deletions defined by high resolution aCGH will enable better genotype–phenotype correlations and prioritizing of candidate genes for the identification of pathways and disease mechanisms.