水稻抗条纹叶枯病基因Stv-bi的分子标记辅助选择

水稻条纹叶枯病是我国黄淮及长江流域粳稻区重要的病害。由于水稻条纹叶枯病的发病受外界条件影响较大,人工接种抗性鉴定比较困难,利用与抗病基因紧密连锁的分子标记进行标记辅助选择对提高抗性育种效率具有重要意义。来自籼稻抗源Modan的Stv-bⁱ是水稻育种中广泛应用的条纹叶枯病抗性基因。本研究设计了与Stv-bⁱ紧密连锁的SSR及STS分子标记,用3个抗条纹叶枯病混合群体F30718(圣稻13/镇稻88)、F50701(武优34/T022//圣稻806)、F60702 (V6/T022//镇稻88)进行分子标记检测和田间条纹叶枯病抗性鉴定,其结果的符合率分别为99.3%、87.7%和91.8%。表明这些分子标记可以用于条纹叶枯病抗性基因Stv-bⁱ分子标记辅助选择。     

抗虫转基因植物鉴定方法的研究进展

农作物受害虫侵害严重,给农业生产带来巨大损失,喷施化学杀虫剂使害虫产生抗药性,且污染环境。近年来,转基因技术研究不断深入,抗虫转化研究工作进展迅速。鉴定转基因植物的方法技术有很多种,在此主要阐述了利用标记基因进行鉴定,分子标记,免役技术三大类方法,并对其原理分别进行了简单介绍。     

棉花黄萎病抗性的分子研究进展

本文综述了棉花黄萎病菌的分子鉴定，棉花黄萎病抗性的遗传基础，分子标记在棉花抗黄萎病方面的应用，棉花黄萎病抗性基因的克隆及转化等方面的研究进展。     

现代农业内涵、特征及发展趋势

现代农业是基于现代产业组织和现代涉农产业系统的培育与完善,横跨一、二、三产业的涉农经济体系,与发达国家农业总产值中占有重要比重的涉农产业(Agribusiness)相当。在科学界定现代农业概念与内涵的基础上,梳理国际涉农产业发展的实践与发展趋势,具有积极的理论和现实意义。     

大白菜抗根肿病基因位点CRa和CRb的分子标记鉴定

利用大白菜抗根肿病基因CRa和CRb分子标记(SC2930和KBr H129J18R)引物组,对78份大白菜材料进行抗根肿病分子标记鉴定。结果表明,在这78份材料中,有34份材料含有SC2930-T(CRa抗病标记)标记,其中杂合抗病位点材料17份,纯合抗病位点材料17份。有37份材料含有KBr H129J18R抗病标记,其中纯合抗病位点材料15份,杂合抗病位点材料22份。有20份材料不含有CRa和CRb所对应的抗病标记,23份材料含有2个抗病标记。该研究初步明确了78份参试大白菜材料所含抗根肿病基因CRa和CRb类型,为大白菜抗根肿病育种提供材料选择依据。     

Fusarium wilt of chickpea: physiological specialization, genetics of resistance and resistance gene tagging

Chickpea wilt caused by Fusarium oxysporum f. sp. ciceris is one of the major yield limiting factors in chickpea. The disease causes 10–90% yield losses annually in chickpea. Eight physiological races of the pathogen (0, 1A, 1B/C, 2, 3, 4, 5 and 6) are reported so far whereas additional races are suspected from India. The distribution pattern of these races in different parts of the world indicates regional specificity for their occurrence leading to the perception that F. oxysporum f. sp. ciceris evolved independently in different regions. Pathogen isolates also exhibit differences in disease symptoms. Races 0 and 1B/C cause yellowing syndrome whereas 1A, 2, 3, 4, 5 and 6 lead to wilting syndrome. Genetics of resistance to two races (1B/C and 6) is yet to be determined, however, for other races resistance is governed either by monogenes or oligogenes. The individual genes of oligogenic resistance mechanism delay onset of disease symptoms, a phenomenon called as late wilting. Slow wilting, i.e., slow development of disease after onset of disease symptoms also occurs in reaction to pathogen; however, its genetics are not known. Mapping of wilt resistance genes in chickpea is difficult because of minimal polymorphism; however, it has been facilitated to great extent by the development of sequence tagged microsatellite site (STMS) markers that have revealed significant interspecific and intraspecific polymorphism. Markers linked to six genes governing resistance to six races (0, 1A, 2, 3, 4 and 5) of the pathogen have been identified and their position on chickpea linkage maps elucidated. These genes lie in two separate clusters on two different chickpea linkage groups. While the gene for resistance to race 0 is situated on LG 5 of Winter et al. (Theoretical and Applied Genetics 101:1155–1163, 2000) those governing resistance to races 1A, 2, 3, 4 and 5 spanned a region of 8.2 cM on LG 2. The cluster of five resistance genes was further subdivided into two sub clusters of 2.8 cM and 2.0 cM, respectively. Map-based cloning can be used to isolate the six genes mapped so far; however, the region containing these genes needs additional markers to facilitate their isolation. Cloning of wilt resistance genes is desirable to study their evolution, mechanisms of resistance and their exploitation in wilt resistance breeding and wilt management.     

北方粳稻分子育种研究进展

本文介绍了北方粳稻分子育种课题的研究情况和所取得的研究成果。目前主要进行两方面的研究，一方面为特异基因型的鉴定：主要有筛选鉴定出抗旱性材料86份，苗期抗寒性材料40份，后期抗寒性材料629份，抗稻瘟病材料28份，对筛选出的抗旱性材料进行了第二轮聚合杂交，共配组合171个。另一方面是关于遗传与生理基础研究，对穗部性状、粒形、产量和品质以及它们之间的关系进行了深入的研究。另外本文对北方粳稻分子育种材料构建过程中存在的问题进行了综合讨论，并讨论北方粳稻分子育种今后的发展方向。     

现代园林工程施工与组织管理探究

现代园林工程是1个极为复杂的工程之一,在工程施工中一般由多个施工单位共同建造,所以,园林工程施工与管理工作有着十分重要的作用。从园林工程施工组织、施工现场管理和施工成本管理等多个方面探讨并研究园林工程施工与管理过程中应该注意的问题,以便提高工程效率,并建造优质的园林工程。     

RAPD and ISSR molecular markers in <Emphasis Type="Italic">Olea europaea</Emphasis> L.: Genetic variability and molecular cultivar identification

Thirty Portuguese and eight foreign olive (Olea europaea L.) cultivars were screened using Random Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeat (ISSR) markers. Twenty RAPD primers amplified 301 reproducible bands of which 262 were polymorphic; and 17 ISSR primers amplified 204 bands of which 180 were polymorphic. The percentage of polymorphic bands detected by ISSR and RAPD was similar (88 and 87%, respectively). The genetic variability observed was similar in the Portuguese and foreign olive cultivars. Seven ISSR and 12 RAPD primers were able to distinguish individually all 38 olive cultivars. Twenty specific molecular markers are now available to be converted into Sequence Characterised Amplified Region (SCAR) markers. Relationships among Portuguese and foreign cultivars is discussed.     

Fatty acid composition of various ectomycorrhizal fungi and ectomycorrhizas of Norway spruce

Whole cell fatty acid (WCFA) compositions of three different structures of ectomycorrhizal (ECM) fungi: sporocarps, pure culture mycelia and ectomycorrhizas were analysed to evaluate the potential use of fatty acid profiles as biomarkers for ECM fungi and ectomycorrhiza-associated bacteria. Sporocarps of Amanita muscaria, Amanita rubescens, Lactarius rufus, Lactarius thejogalus, Leccinum scabrum, Paxillus involutus, Russula foetens, Russula rosea, Russula vesca, Suillus grevillei, Tylopilus felleus, Xerocomus badius, Xerocomus subtomentosus, pure cultures of A. muscaria, P. involutus, X. badius, X. subtomentosus, Suillus bovinus Suillus luteus and seven ectomycorrhizal morphotypes of Norway spruce were examined. Our results revealed species-specific composition of fatty acids of fungal sporocarps and pure culture mycelia. Ectomycorrhizal morphotypes distinguished and identified by morphological and molecular methods (PCR-RLFP and sequencing) created specific fatty acid profiles. The dominating fatty acids in pure cultures and sporocarps were 18:2ω6,9, 18:1ω9 and 16:0, whereas ectomycorrhizas also contained plant and bacterial specific fatty acids. Especially, fatty acids specific to Gram-positive bacteria 15:0 anteiso and 17:0 anteiso were present in relatively high amounts and suggested that these bacteria are dominating in the examined Norway spruce mycorrhizosphere. In conclusion, our results show that fatty acid based methods can be useful in studies of ectomycorrhizal fungi, both as a quick method for differentiation of fungal species and also in studies of mycorrhiza-associated microorganisms in the field.