广东果树上17种拟茎点霉的RAPD分析   总被引：3，自引：0，他引：3  

姜子德  梅曼彤  戚佩坤 《植物病理学报》2003,33(1):35-39

 自320个随机引物中筛选出适于拟茎点霉属真菌种间亲缘关系分析的15个随机引物,并优化了RAPD分析的扩增体系,在此基础上,对广东果树上17种拟茎点霉进行了RAPD分析。各菌株间的Nei相似系数UPGMA法聚类结果表明:来源于不同地区的2个Phomopsis mangiferae Ahmad菌株和2个P.macadami Z.D.Jiang et P.K.Chi菌株都分别以0.636和0.589的相似系数两两首先聚在一起,而不同的种则只在小于0.54的相似系数范围内聚类,体现了种间及种内的亲缘关系差异程度;聚类群与寄主植物不具相关性,同种植物上的不同拟茎点霉,即使是分自相同寄生部位也不能聚在一类;支持形态学上将生于柑桔枝和黄皮茎、沙梨叶和果、杨梅叶和枝以及同是生于龙眼叶的共8个拟茎点霉分别鉴定为不同的种,而不支持将P. cytosporella Penz.et Sacc.与P. mangiferae合并为一个种的观点;RAPD技术可作为拟茎点霉属真菌种间的亲缘关系分析的重要手段。  相似文献   

英语教学翻译与翻译教学          下载免费PDF全文

李加强 《安徽农业大学学报》2006,(6):118-121

英语教学任务和目标是在不同阶段培养相应的语言能力和交际能力,其有机组成部分包括教学翻译与翻译教学,这是两种概念不同,目的相异但又相互联系的教学设计类型。本文尝试由语言教学理论和语言教学角度探讨二者之间的关系,认为二者在概念和目的上不容混淆,但二者教学上存在着相互联系。  相似文献   

猪源隐孢子虫感染小鼠模型的建立     

《中国兽医科技》2006,36(4):301-305

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试论灰色系统关联度分析法在生物科学研究中应用的合适性   总被引：1，自引：0，他引：1  

杨诗兴 《家畜生态》2003,24(4):10-13

灰色系统关联度分析法的主要研究对象是社会经济等非技术的抽象系统。近年来，在生物科学领域如畜牧、兽医、草原等技术性强和具体系统的科学研究中，发现有应用该法分析其试验数据的论文。经研究核实，应用该法分析生物科学研究的数据，似欠合适。这可能是由于该方法本身有不足处，或由于论文作者误用该法。特提出供读者与学者讨论与研究。  相似文献   

Acanthochondria priacanthi (Copepoda: Chondracanthidae) as a biological indicator for stock identification of sandfish Arctoscopus japonicus (Steindachner)     

Takashi  YANAGIMOTO  Kenji  KONISHI 《Fisheries Science》2004,70(2):336-338

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Can wild relatives of sorghum provide new sources of resistance or tolerance against Striga species?     

A L Gurney  M C Press  & J D Scholes 《Weed Research》2002,42(4):317-324

Summary The genus Striga contains some of the most noxious parasitic plants, which have a devastating impact on cereal production in Africa; of most importance are Striga hermonthica and Striga asiatica . Complete resistance to infection by Striga species does not exist in cultivated cereals. Of great interest is the possibility that wild relatives of cereals may provide a genetic basis for resistance or tolerance to infection and may be of enormous value for the development of resistant crops. A wild relative of cultivated sorghum, Sorghum arundinaceum , demonstrated tolerance to infection by S. asiatica , with little impact of S. asiatica on host growth or grain production compared with the detrimental impact of the parasite on cultivated sorghum. Infection by S.hermonthica , however, had a significant influence on host performance for both wild and cultivated sorghum. Differences in host:parasite responses may be explained by the timing of parasite attachment and differences in host specificity for these two Striga species.  相似文献   

Study of Resistance to Orobanche ramosa in Host (Oilseed Rape and Carrot) and Non-host (Maize) Plants     

Naïma Zehhar  Pascal Labrousse  Marie-Claire Arnaud  Christian Boulet  Driss Bouya  André Fer 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(1):75-82

Orobanche ramosa is a parasitic Angiosperm responsible for severe yield losses in several economical crops. It is a serious threat in oilseed rape in France and Morocco and is appearing in carrot crops in Morocco. In this study, several varieties of oilseed rape and carrot were screened in order to identify resistant cultivars and to characterize the resistance mechanisms involved. All the 15 oilseed rape varieties tested were susceptible. In carrot, the varieties 'Colmar à coeur rouge' and 'Nantaise demi-longue' were susceptible, whereas 'Palaiseau' and 'Buror' were resistant. In the susceptible 'Colmar à coeur rouge' carrot no defence reactions were found and the development of the parasite inhibited carrot tap root formation. In the resistant carrot varieties, the parasite germinated, became attached to the host root but became necrotic before emergence. In 'Buror' carrot, formation of a mechanical barrier was associated with the restriction to the cortex of the parasite. In maize cv. 'Vigni', a non-host of O. ramosa, thickening of xylem vessels, cell divisions in the central cylinder and formation of an encapsulation layer were observed in association with restricted development of Orobanche haustoria.  相似文献   

《侵权责任法》背景下的劳动关系辨析     

许添元 《安徽农业大学学报》2016,(3):77-81

企业未办理营业执照就进行生产，工人工作时受伤，本应按照《工伤保险条例》进行赔偿，适用无过错原则。然而，一些基层法院认为，双方形成了个人之间的劳务关系，应按《侵权责任法》的规定，适用过错相抵原则，这严重损害了劳动者的合法权益。劳动关系与劳务关系相比较，劳动关系具有产业性、劳动者的从属性、生产的组织性和期限的长期性等特征。通过对劳动关系内涵的分析，有助于我们正确处理案件，就不会错误地将本是劳动关系的案件认定为双方存在劳务关系，也不会将工伤案件按劳务关系处理。  相似文献   

The distributions of Chinese yak breeds in response to climate change over the past 50 years          下载免费PDF全文

Jianguo Wu 《Animal Science Journal》2016,87(7):947-958

The effects of prior climate change on yak breed distributions are uncertain. Here, we measured changes in the distributions of 12 yak breeds over the past 50 years in China and examined whether the changes could be attributed to climate change. Long‐term records of yak breed distribution, grey relational analysis, fuzzy sets classification techniques and attribution methods were used. Over the past 50 years, the distributions of several yak breeds have changed in multiple directions, mainly shifting northward or westward, and most of these changes are related to the thermal index. Driven by climate change over the past years, the suitable range and the distribution centers of certain yak breeds have changed with fluctuation and have mainly shifted northward, eastward or southward. The consistency of observed versus predicted changes in distribution boundaries or distribution centers is higher for certain yak breeds. Changes in the eastern distribution boundary of two yak breeds over the past 50 years can be attributed to climate change.  相似文献   

Ye Yaxin, Jin Jin, Wang Wenjing, Xu Yu     

叶亚新  金琎  王文菁  徐钰 《中国农学通报》2005,21(4):168-168

研究Nacl浓度与小麦幼苗生长分裂的关系及对小麦幼苗的遗传损伤。实验结果表明：小麦幼苗生长在含NaCl的介质中，其幼苗生长被抑制，根尖细胞有丝分裂指数下降,幼苗的分裂指数、遗传损伤与盐浓度间有一定的线性关系。结果显示：有丝分裂指数与处理浓度间呈负相关。这表明：NaCl浓度高或作用时间延长时对小麦细胞具有遗传学毒性，小麦幼根细胞有丝分裂指数可以作为监测环境中NaCl含量的定量指标。  相似文献