利用SRAP和ISSR标记分析广东茶树种质资源的遗传多样性

利用EST-SSR标记对云南134份茶树资源遗传多样性和亲缘关系进行了分析。30对引物共检测到等位位点127个,平均每对引物产生423个;共检测到263个基因型,平均每对引物所扩增的基因型有88个;遗传多态性信息含量平均达0501,高于其它地区的相关研究结果,表明云南茶树资源具有丰富的遗传多样性。资源间的平均遗传距离和相似系数分别为0413和0597,说明资源间的遗传差异比较大,遗传基础较宽。聚类可将134份资源划分为4大组。8个种群间的遗传相似系数变异范围为0753～0981,平均遗传相似系数为0891,表明不同种群间的遗传差异比较小。云南茶树资源间亲缘关系的揭示为今后茶树资源保存和新品种选育提供了一定理论依据。     

Insights into the role of ethylene perception in tomato resistance to vascular infection by Verticillium dahliae

A Tobacco rattle virus (TRV)-based virus-induced gene silencing (VIGS) system was employed to investigate the role of the tomato ethylene receptor ETR4. By comparing wilting symptoms of verticillium wilt in wild-type, ethylene-insensitive Never ripe ( Nr ) mutant tomato plants and ETR4 -silenced plants, it was demonstrated that disease severity in the Nr and ETR4 -silenced plants was statistically reduced compared to wild-type plants. Disease incidence and severity were reduced by 11 and 20%, respectively, in the Nr plants compared to the wild-type plants, at 33 days post-inoculation (d.p.i.). In the ETR4 -silenced plants, disease incidence and severity were reduced by 14 and 15%, respectively, compared to the TRV -only-inoculated plants, at 37 d.p.i. Quantification of Verticillium dahliae by qPCR revealed that the reduction in symptom severity in the Nr plants was associated with significant reduction of growth of the pathogen in the vascular tissues of the Nr plants compared to that in the wild-type plants, suggesting that impaired perception of ethylene via the Never-ripe receptor results in increased disease resistance. Fungal reduction was evident at each sampling day in the Nr plants, ranging from 1·5 to 1·75 times less than that in the wild-type plants. Fungal quantification in the ETR4- silenced and TRV -only-inoculated plants showed similar levels of fungal biomass.     

整合质量数量性状构建作物核心种质的策略研究

质量性状和数量性状在不同水平反映了个体间的遗传差异,现有遗传相似性的度量往往割裂两者的信息.本文提出了整合质量性状和数量性状评价个体间遗传相似性的统计策略,调整的欧氏距离能有效地度量个体间的差异,并能很好地处理性状数据的缺失.实例分析了中国农业科学院、华南农学院、广东省农科院水稻生态研究室收集和调查的2262份水稻种质资源10个质量性状和15个数量性状的数据资料,用调整的欧氏距离及不加权类平均法进行群体分类,多次聚类优先取样法抽取8个不同容量的巢式子集并进行遗传多样性比较.结果表明:基于整合信息构建的核心种质同时具有较高的数量性状和质量性状遗传多样性;仅用质量性状信息不足以评价个体间的遗传差异;核心种质构建中应该采用数量性状的信息,同时整合质量性状的信息.     

黑番鸭血管活性肠肽受体-1基因(VIPR-1)的cDNA克隆及其组织表达特性分析

最近的研究表明,血管活性肠肽(VIP)与家禽的就巢习性密切相关。本研究采用反转录PCR方法从黒番鸭(Cairina moschata)母鸭下丘脑组织中克隆了血管活性肠肽受体(VIPR-1)基因的cDNA序列,长度为1125bp,编码355个氨基酸(GenBank登录号:JN625215)。序列比对结果表明,该序列与家禽(鸡、火鸡、鹌鹑)和哺乳动物(人、小鼠、猪、牛)的基因序列分别有93%~94%和69%~71%的同源性,而相应氨基酸序列的同源性分别为96%和70%~72%。荧光定量PCR结果发现,黒番鸭VIPR-1基因的表达量在产蛋期、就巢期和休产期差异显著(P<0.05)或极显著(P<0.01),就巢期表达量最高,休产期次之,产蛋期表达量最低,表明VIPR-1基因与繁殖阶段变化密切相关;对不同组织VIPR-1的表达量分析发现,VIPR-1在垂体、下丘脑和卵巢中均有表达,其中垂体最多,其次是下丘脑,卵巢中的表达量最低,差异极显著(P<0.01)。研究结果提示,VIPR-1基因具有高度保守性,参与下丘脑-垂体-卵巢轴(特别是垂体)对黑番鸭就巢行为的调控。     

Genetic mapping and utilization of quantitative trichome-mediated insect resistance in potato

Introgression of trichome-mediated insect resistance from the wild speciesSolanum berthaultii has become a major focus of the potato improvement program at Cornell University during the past twelve years. Several quantitative characters are involved in this resistance which is effective against a wide range of pest types. Correlative biochemical assays have been developed to assay specific components of the resistance, and the effects of the resistance on the target pests have been studied. Quantitative laboratory assays and specific measurements of insect behavior and biology have increased the precision of selection and enable the investigation of the genetic control of the resistance.We are currently using restriction fragment length polymorphisms (RFLPs) for genetic mapping of factors controlling the trichome traits fromS. berthaultii. Backcrosses to both the wild and the cultivated species parents have been evaluated for phenotypes contributing to the resistance mechanism, including trichome density, sucrose ester and polyphenol oxidase production by the trichomes, and the enzymatic browning reaction responsible for insect entrapment. Genetic maps are being developed for these progenies, using RFLP markers previously mapped in potato. Field and greenhouse trials under insect infestations are also being conducted with the mapping progeny. Our goal is to locate genes responsible for quantitative insect resistance by correlating RFLP variation at mapped loci with the trichome phenotypes and insect resistance. Genetic markers for these traits will be useful in transfer of the effective wild chromosomal segments into and among tetraploid potatoes, and for a better understanding of the resistance mechanism.     

苗圃土壤肥力评价及肥力系数与苗木生长的相关性

以广东河源中心苗圃（共有5个不同地块，分别记为地块A，B，C，D，E）为研究对象，选用土壤质地、容重、pH、有机质、全氮、碱解氮、速效磷和速效钾等8项属性作为评价指标，运用修正的内梅罗（Nemoro）公式，对土壤肥力进行定量综合评价，并对肥力系数与苗木生长指标的相关性进行分析。结果表明，苗圃土壤肥力系数P平均为1．06～2．48，P最小、为0．03～0．97，综合肥力系数P为0．66～1．65，不同地块、同一地块不同土层同一系数差异很大。该苗圃仅有地块A，B和D的表层（0～20cm）土壤和地块A的表下层（20～40cm）土壤肥力达到一般水平，上述地块的其他土层和地块C和E的所有土层均属贫瘠。土壤氮素缺乏是导致P值低的主要原因。阔叶树苗高与P平。和P呈显著正相关关系；阔叶树单株苗木生物量与P平均，P最小、和P均呈显著正相关关系，表明P平均和P能较好反映苗圃土壤肥力水平，而单株苗木生物量是体现苗圃土壤肥力水平的适宜生物指标。表7参11     

A genetic linkage map in southern‐by‐spring oat identifies multiple quantitative trait loci for adaptation and rust resistance

We developed 178 recombinant inbred lines from a southern‐by‐spring oat population designated as “TxH.” These lines were genotyped to generate a high‐quality linkage map that resolved 6,902 markers into 21 linkage groups that matched closely with the latest hexaploid oat consensus map. Three major quantitative trait loci (QTLs) affecting heading date were found in locations that are consistent with known QTLs and candidate genes, and two other QTLs affecting heading date were found in novel locations. Five QTLs affecting plant height were found. Both sets of QTLs are responsible for transgressive segregation observed for these two traits. Four QTLs affecting resistance to crown rust, caused by the pathogen Puccinia coronata f. sp. avenae, were identified. Two of these QTLs are consistent with known clusters of rust resistance genes, while two may represent new locations of novel rust resistance genes. A complete set of SNP sequences suitable for generating markers for molecular selection is provided.     

品种区域试验主要决选指标及其参数的研究——Ⅳ.参数数量分类与区试品种分类

本文根据变量理论分布对区试中b值及CV值参数的数量分类,提出了适于目前普及推广的查表计算法。在此基础上,对区试品种提出了按主要生产性能指标以量定性的评定分类体系。从而推出可排除主观随意性干扰、较为完整严密的区试汇总模式,并以范例作了运用说明。     

非均质物料链式组合称重定量算法优化与试验

非均质物料质量差异较大且不可分割,组合称重定量过程中组合对象不确定,存在组合称重定量精度与组合速度的矛盾.该研究针对链式组合称重定量系统,提出以定量精度及组合效率为目标,对组合样本数和抽样数进行优化分析,达到保证组合称重定量精度下,减少数据计算量以提高组合定量速度的目的.研究表明,在相同允许组合误差下,增大组合样本数可...     

Analysis on Polymorphisms of Three CNV Regions in Five Pig Breeds

The paper was aimed to investigate the polymorphism of copy number variation (CNV) in different pig breeds.Three CNV regions of CNVR91,CNVR92 and CNVR143 were chosen from the porcine SNP60 chip genotyping results.The polymorphisms of three CNVs were determined by Real-time quantitative PCR method,taking five pig breeds as samples,including Yorkshire pig,Xiang pig,Kele pig,Nuogu pig and Rongchang pig breeds.The results showed that the dominant status of CNVR91 was loss in Xiang pig,while it was normal in other four pig breeds.The major type of CNVR92 was deletion in Xiang pig,Yorkshire pig,Kele pig and Rongchang pig breeds,with a high normal percent in Nuogu pig.For CNVR143,the dominant event was gain in Xiang pig and Nuogu pig breeds,but it was not diverse in other three pig breeds.These results indicated that three CNV regions emerged with polymorphism in five pig breeds,which might have effects on gene expression in CNV regions and physiological function by dosage effect especially in Xiang pig,Nuogu pig and Kele pig breeds.