常见病原菌基因组DNA快速提取试剂盒研制

以单增李斯特菌、金黄色葡萄球菌等6种常见食源性致病菌为研究对象,优化试剂盒工艺参数,采用琼脂糖凝胶电泳及OD260/OD280分析基因组DNA提取效果。结果表明,试验试剂盒可在30 min内完成基因组DNA提取,对常见10类食品样品抗基质干扰能力强。与实时荧光PCR技术联用,检测染菌量1~10 cfu·25 g-1食品样品时,仅一次增菌可得阳性结果;市售食品样品检测与国标方法结果无显著差异。所研制病原菌基因组DNA提取试剂盒适用于食品病原菌快速检测。     

贵阳市市售猪肉中食源性致病菌分离鉴定

为了解贵阳市市售猪肉中食源性致病菌的污染情况,采集贵阳市市售猪肉样品60份,按照相关国家标准分离鉴定样品中的沙门氏菌、志贺氏菌、单核细胞增生李斯特菌、金黄色葡萄球菌、肠出血性大肠杆菌。结果表明:样品中食源性致病菌总检出率为13.33%,其中沙门氏菌检出率为6.67%,金黄色葡萄球菌检出率为3.33%,志贺氏菌检出率为1.67%,单核细胞增生李斯特菌检出率为1.67%,肠出血性大肠杆菌未检出。说明贵阳市市售猪肉中沙门氏菌的污染率最高,金黄色葡萄球菌、志贺氏菌和单核细胞增生李斯特菌也存在一定污染情况。     

食源性病原菌检测方法研究进展

食品中的病原微生物是影响食品安全的主要因素之一,传统检测食源性病原菌的方法繁琐复杂、周期较长,随着分子生物学技术和微电子技术等的发展,快速、简便、特异的检测方法成为研究目标。介绍并分析了几种检测食源性病原菌的方法及其特点,并就其发展历程和应用进行阐述。     

应用拟杆菌作为水体粪源污染指示菌的研究进展

粪源污染是水环境安全的重要威胁。传统的指示微生物在水体粪源检测中存在较多局限性,难以准确溯源水体所受粪源污染。拟杆菌属微生物因其具有在人畜肠道中的绝对数量优势和突出的粪源指示作用等优点,在粪源污染监测中日渐受到重视。该文阐述了拟杆菌作为指示微生物在应用于示踪水体粪源污染时的优势,并针对水环境中拟杆菌的检测方法及其在受污...     

Genetic relationships among Chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L<Emphasis Type="Italic">.</Emphasis>) genotypes based on the SSRs at the quantitative trait Loci for resistance to Ascochyta Blight

Breeding for resistance to ascochyta blight in chickpea has been challenged by several factors including the limited sources of good resistance. Characterization of a set of genotypes that may contain different genes for resistance may help breeders to develop better and more durable resistance compared to current cultivars. The objective of this study was to evaluate the genetic relationships of 37 chickpea germplasm accessions differing in reaction to ascochyta blight using Simple Sequence Repeat (SSR) markers linked to Quantitative Trait Loci (QTL) for resistance. The results demonstrated that ILC72 and ILC3279, landraces from the former Soviet Union, had SSR alleles that were common among the kabuli breeding lines and cultivars. A lower SSR allele diversity was found on LG4 than on other regions. No correlation was found between the dendrogram derived using SSRs at the QTL regions and the SSRs derived from other parts of the genome. The clustering based on 127 alleles of 17 SSRs associated with the QTL for ascochyta blight resistance enabled us to differentiate three major groups within the current germplasm accessions. The first group was the desi germplasm originating from India and cultivars derived from it. The second group was a mix of desi genotypes originating from India and Greece, and kabuli breeding lines from ICARDA and the University of Saskatchewan. The third and largest group consisted of landraces originating mostly from the former Soviet Union and breeding lines/cultivars of the kabuli type. Several moderately resistance genotypes that are distantly related were identified. Disease evaluation on three test populations suggested that it is possible to enhance the level of resistance by crossing moderately resistant parents with distinct genetic backgrounds at the QTL for resistance to ascochyta blight.     

Validation of a QTL for resistance to ascochyta blight linked to resistance to fusarium wilt race 5 in chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.)

Ascochyta blight caused by Ascochyta rabiei and fusarium wilt caused by Fusarium oxysporum. f. sp. ciceris are the two most serious diseases of chickpea (Cicer arietinum). Quantitative trait loci (QTL) or genes for ascochyta blight resistance and a cluster of resistance genes for several fusarium wilt races (foc1, foc3, foc4 and foc5) located on LG2 of the chickpea map have been reported independently. In order to validate these results and study the linkage relationship between the loci that confer resistance to blight and wilt, an intraspecific chickpea recombinant inbred lines (RIL) population that segregates for resistance to both diseases was studied. A new LG2 was established using sequence tagged microsatellite sites (STMS) markers selected from other chickpea maps. Resistance to race 5 of F. oxysporum (foc5) was inherited as a single gene and mapped to LG2, flanked by the STMS markers TA110 (6.5 cM apart) and TA59 (8.9 cM apart). A QTL for resistance to ascochyta blight (QTL_AR3) was also detected on LG2 using evaluation data obtained separately in two cropping seasons. This genomic region, where QTL_AR3 is located, was highly saturated with STMS markers. STMS TA194 appeared tightly linked to QTL_AR3 and was flanked by the STMS markers TR58 and TS82 (6.5 cM apart). The genetic distance between foc5 and QTL_AR3 peak was around 24 cM including six markers within this interval. The markers linked to both loci could facilitate the pyramiding of resistance genes for both diseases through MAS.     

重庆试种期问绿玉树病害初报

绿玉树是一种集药用、观赏等多用途于一体的树种，病害的发生严重影响了绿玉树在重庆试种期间的健康生长。病害调查和病原鉴定结果表明：试种期间危害最严重的病害是灰霉病和根结线虫病。其中灰霉病由葡萄孢霉（Botrytis sp．）危害所致，可使绿玉树的各个部位发生水渍状腐烂，上生灰色霉层，持续阴雨有利于病害的发生和流行。南方根结线虫（Meloidogyne incognita）为害引起根结线虫病，使绿玉树根部组织过度生长形成瘤状根结。发生严重可导致根部坏死腐烂。     

Implementation of soil solarization in Greece: conclusions and suggestions

The use of soil solarization in Greece is described, indicating methods of reducing the period of solarization by using impermeable plastic sheets and combining it with the addition of antagonistic bacteria.     

Phytotoxicity of solanapyrones A and B produced by the chickpea pathogen Ascochyta rabiei(Pass.) Labr. and the apparent metabolism of solanapyrone A by chickpea tissues

When chickpea shoots were placed in solanapyrone A, the compound could not be recovered from the plant and symptoms developed. These consisted of loss of turgor, shrivelling and breakage of stems and flame-shaped, chlorotic zones in leaflets. In similar experiments with solanapyrone B, only 9.4% (22 μ g) of the compound taken up was recovered and stems remained turgid but their leaflets became twisted and chlorotic and some abscized.Cells isolated from leaflets of 12 chickpea cultivars differed by up to five-fold in their sensitivity to solanapyrone A and this compound was 2.6–12.6 times more toxic than solanapyrone B, depending on cultivar.Glutathione reacted with solanapyrone A in vitro reducing its toxicity in a cell assay and forming a conjugate. Measurement of reduced glutathione concentration and glutathione-S-transferase (GST) activity among cultivars showed that the differences of their means were highly significant and both were negatively and significantly correlated with their sensitivity to solanapyrone A. Treatment of shoots with solanapyrone A enhanced total, reduced and oxidized glutathione content as well as GST activity 1.26-, 1.23-, 1.50- and 1.94-fold, respectively. Similarly, treatment of shoots with the safener, dichlormid, also raised total, oxidized and reduced glutathione levels and GST activity 1.42-, 1.07-, 1.43-, 1.42-fold, respectively. Cells isolated from shoots treated with dichlormid at 150 and 300 μ g per shoot were 2.45 and 2.66 times less sensitive to solanapyrone A, with LD₅₀values of 71.5 and 77.8 μ g ml⁻¹, respectively, as compared to 29.2 μ g ml⁻¹for controls.     

Biological Seed Treatment of Cereals with Fresh and Long-term Stored Formulations of Clonostachys rosea: Biocontrol Efficacy Against Fusarium culmorum

In six field experiments, seed treatment with Clonostachys rosea (IK726) significantly reduced disease caused by Fusarium culmorum. IK726 was active against the pathogen at average soil temperatures at sowing ranging from 6.2 to 12 °C. Both in the field experiments and in growth chamber experiments conducted in sand, dried and stored conidia of IK726 controlled F. culmorum as effectively as freshly harvested conidia. A high correlation was found between disease index ratings from field experiments and from corresponding growth chamber sand tests. Amendment with the stickers Pelgel or Sepiret did not influence control activity. The effective dosages of IK726 (cfu/seed) were estimated in bioassays and were very similar for freshly harvested conidia and for dried conidia. With a density of > 5×10³ conidia per seed more than 80% disease control was repeatedly obtained with both types of conidia.