六甲基六元瓜环与紫精衍生物作用体系及其除草活性研究

以紫精衍生物为研究对象,利用核磁共振技术、紫外吸收光谱和循环伏安法等方法,发现六甲基六元瓜环包结了紫精衍生物的烷基部分,形成2∶1比例的哑铃型包结配合物.结果表明,随着紫精衍生物烷基链的增长,紫精衍生物对杂草的除草活性依次减弱,且六甲基六元瓜环可增强紫精衍生物的除草活性.     

瓜类遗传连锁图谱构建的研究现状及比较分析

 截至目前,西瓜、黄瓜及甜瓜的全基因组测序工作已经基本完成,利用高密度饱和遗传连锁图谱将基因组序列锚定到染色体的具体位置并确定其在染色体上的方向,这为进一步开展基因组分析研究奠定了基础。本文中综述了瓜类遗传连锁图谱构建的研究现状并对遗传连锁图谱进行了比较分析。     

4 份野生瓜类材料抗病性及形态特征和SSR 亲缘关系研究

 对4份野生瓜类材料进行抗病性鉴定、形态学性状调查、细胞学鉴定及SSR亲缘关系分析。结果表明,4份野生材料分别为野生红瓜[Coccinia grandis（L.）Voigt],野生小马泡（Cucumis bisexualis A. M. Lu et G. C. Wang ex Lu et Z. Y. Zhang）,野生栝楼（Trichosanthes L.）和野生红籽瓜（Citrullus lanatus ssp. vulgaris var. megalaspermusLin et Chao）,染色体数依次为2n = 24,2n = 24,2n = 22,2n = 22。4份野生材料野生性状明显,部分食用价值低劣,难以直接利用,但其表现出植株生长茂盛,其中野生红瓜、野生栝楼和野生红籽瓜材料高抗枯萎病和白粉病,野生小马泡材料感枯萎病和白粉病。从130对SSR引物组合中筛选出15对引物分析供试材料,共得到271条清晰可辨条带,其中多态性条带124条,多态性条带百分率为45.8%。4份野生材料与4种瓜类（甜瓜、黄瓜、西瓜、南瓜）栽培品系间的相似系数为0.62 ~ 0.96。WINBOOT程序聚类分析表明,野生红瓜、野生小马泡、野生栝楼和野生红籽瓜分别与黄瓜、甜瓜、南瓜和西瓜亲缘关系最近。     

瓜类蔬菜子叶离体培养的研究进展

本文对瓜类蔬菜子叶离体培养的研究进行综述,包括再生途径、影响因素及应用等方面研究的进展,讨论了瓜类蔬菜子叶离体培养存在的问题和今后研究的重点。     

Structure and temporal shifts in virulence of Pseudoperonospora cubensis populations in the Czech Republic

The structure and temporal dynamics of the virulence of Pseudoperonospora cubensis (causal agent of cucurbit downy mildew) were studied in pathogen populations in the Czech Republic from 2001 to 2010. A total of 398 P. cubensis isolates collected from Cucumis (Cm.) sativus, Cm. melo, Cucurbita (Cr.) maxima, Cr. pepo, Cr. moschata and Citrullus lanatus were analysed for variation in virulence (pathotypes). Virulence was evaluated on a differential set of 12 genotypes of cucurbitaceous plants. All isolates of P. cubensis were characterized by their level of virulence (classified according the number of virulence factors, VF; low VF = 1–4, medium VF = 5–8, high VF = 9–12): high (75%), medium (24%) and low (1%). The structure and dynamics of virulence in the pathogen populations were expressed by pathotypes using tetrad numerical codes and a total of 67 different pathotypes of P. cubensis were determined. The most susceptible group of differentials was Cucumis spp., while the lowest frequency of virulence was recorded on Cr. pepo ssp. pepo, Ci. lanatus and Luffa cylindrica. A high proportion (c. 90%) of isolates was able to infect cucurbit species Benincasa hispida and Lagenaria siceraria, which are not commonly cultivated in the Czech Republic or elsewhere in central Europe. In the recent pathogen populations (2008–2010) there was prevailing frequency (70–100%) of isolates with high numbers (9–12) of virulence factors. ‘Super pathotype’ 15.15.15 was often observed in the study within the pathogen populations and was one of the four most frequently recorded pathotypes. Pseudoperonospora cubensis populations shifted to a higher virulence over time. From 2009 the pathogen population changed dramatically and new pathotypes appeared able to establish natural and serious infection of Cucurbita spp. and Ci. lanatus, which was not observed in 2001–2008. Generally, virulence structure and dynamics of P. cubensis populations are extremely variable in the Czech Republic.     

硒对植物的生理作用及富硒瓜菜研究进展

中国72％的土壤缺硒,硒对人体健康发挥着重要作用。根据有关文献阐述了富硒瓜菜的特点,瓜菜硒含量的国家标准;植物对硒的吸收、转运及同化的机理;硒对作物产量、品质、种子萌发、根系活力和叶绿素含量等的影响。此外还介绍了硒对植物矿质营养吸收、抗逆性、酶活性、抗氧化作用及重金属拮抗等的影响;简述了硒在厚皮甜瓜和西瓜上的研究现状：提出了富硒农业发展中存在的问题及未来的发展方向。     

Progress in grafting watermelon to manage Verticillium wilt

Vegetable grafting for disease management was first used successfully when watermelon grafted onto a Cucurbita moschata rootstock overcame Fusarium wilt. Interspecific grafting has since been used effectively to mitigate several soilborne pathogens in a variety of solanaceous and cucurbitaceous cropping systems. Verticillium wilt caused by Verticillium dahliae is a significant disease in watermelon crops and is difficult to manage. Current management practices, including crop rotation, soil fumigation, and host resistance, are insufficient due to the ability of microsclerotia to persist in absence of a host, lack of efficacy of soil fumigants, and limited availability of resistant cultivars. Watermelon grafted onto commercial cucurbit rootstocks have increased tolerance to Verticillium wilt, although no cucurbit rootstocks are known to be completely resistant. Verticillium wilt incidence decreased on grafted plants grown in artificially and naturally infested soils, while scion health and growth as well as rootstock root mass and vigour increased. Commonly used rootstocks are Lagenaria siceraria, C. moschata, and C. maxima × C. moschata; of these, only C. maxima × C. moschata ‘Tetsukabuto’ reduced severity of Verticillium wilt across several scion cultivars, locations, years, and soil densities of V. dahliae. Although studies on Verticillium wilt resistance of grafted watermelon are few, their combined results suggest the threshold of V. dahliae soil density for watermelon may be around 5–12 cfu/g. This review summarizes available information on Verticillium wilt of watermelon and effects of different rootstock × scion combinations, assisting growers and breeding programmes in decisions to adopt watermelon grafting for management of Verticillium wilt.     

河南温县地黄上瓜类褪绿黄化病毒的鉴定及其CP序列分析

<正>0引言地黄(Rehmannia glutinosa Libosch．)为玄参科(Scrophulariaceae)多年生草本植物,根部为传统中药材,主要产区分布在山东、山西、河南、河北、北京等地。地黄栽培中通常使用块根进行无性繁殖,易导致病毒病积累发生,从而严重影响地黄的产量与质量^[1]。目前侵染地黄的植物病毒主要有烟草花叶病毒(tobacco mosaic virus,TMV)、地黄花叶病毒(rehmannia mosaic virus,ReMV)、油菜花叶病毒(youcai mosaic virus,YoMV)、蚕豆萎蔫病毒2号(broad bean wilt virus 2,BBWV2)、车前草花叶病毒(plantago asiatica mosaic virus,P1AMV)等^[2]。