梨栽培品种SSR鉴定及遗传多样性

应用SSR技术对梨41个栽培品种进行遗传多样性分析, 12对SSR引物扩增出114个等位基因, 平均每个位点915个。位点杂合度在0.1517～0.7079之间, 遗传多样性指数为0.4630。用两对引物(BGT23b和CHO2D11) 即可区分除芽变品种之外的全部供试品种。系统聚类分析将41个梨品种分为2大类, 即西洋梨和东方梨。原产中国的秋子梨、白梨和部分砂梨品种归类相互交错; 库尔勒香梨和其他新疆梨聚在一起; 我国砂梨品种宝珠梨、德胜香, 日本砂梨品种新世纪、丰水以及韩国砂梨品种黄金梨聚在一起。秋白与蜜梨, 南果梨与满园香、秋子、八里香相似系数高, 分别属于同一品种群。金花梨与金川雪、苍溪雪起源演化相关。     

不同地理来源旱稻种质资源的遗传多样性分析

用38对SSR引物对144份不同地理来源的旱稻种质资源进行遗传多样性分析。结果表明,共检测到137个等位变异,平均每对引物检测到3.6个,等位变异范围2~9。Nei基因多样性指数（He）在0.440（RM162）~0.854（RM335）之间,平均0.598。旱稻种质资源亚种间SSR多样性差异明显,籼稻的等位基因数目和Nei基因多样性指数（Na = 3.5,He = 0.558）明显高于粳稻（Na = 3.2,He = 0.415）。Nei基因多样性指数以亚洲最高,非洲最低,亚洲其他（He = 0.594）>中国（He = 0.593）>南美（He = 0.545）>非洲（He = 0.512）。AMOVA分析表明,旱稻种质资源的遗传变异主要来自亚种内（占总变异的76.3％）,亚种间遗传分化极显著。系统聚类能较好地区分籼粳亚种,但不能区分地理组。旱稻种质资源丰富的遗传多样性为水稻节水抗旱品种的选育提供了条件。     

一个水稻抽穗期主基因Hd(t)的遗传分析及分子定位

从缙恢10/R21的杂种后代中发现了一个抽穗期稳定遗传的迟熟恢复系N91(110~114 d),以早熟不育系金23A(89~94 d)作为杂交和回交亲本,获得的F₂和BC₁F₁群体抽穗期均表现双峰分布,χ²检测表明其抽穗期受一对主基因控制,暂命名为Hd(t)。在400多对SSR引物中筛选出5对在早熟基因池和迟熟基因池中表现差异的引物,进行单株验证,用回交群体进行基因定位,发现位于第7染色体长臂末端的SSR标记RM1364和RM3555与Hd(t)连锁,遗传距离分别为32.7 cM和22.5 cM。在目标区域进一步合成8对SSR引物,将Hd(t)基因定位在RM22143与第７染色体末端之间,与RM22143相距12.9 cM。该结果为Hd(t)基因的精细定位、分子标记辅助育种和基因克隆奠定了基础。     

小麦抗叶锈病基因Lr45的SSR分子标记

用定位于2A染色体的59对SSR、EST-SSR引物,对小麦抗叶锈病基因Lr45进行分子标记,共筛选出11对揭示TcLr45多态性的引物。用157株F₂抗感群体对这11对引物进一步检测,得到4个与Lr45共分离的SSR标记(Xgwm95、Xgwm47、Xgwm372和Xgwm122)。将经PAGE检测的标记Xgwm95的抗感差异带及Xgwm47的抗性片段进行克隆测序发现其中含有微卫星序列,且均为二核苷酸重复。Xgwm372和Xgwm122经琼脂糖凝胶电泳发现与Lr45的供体黑麦有共同的标记片段,可直接用于分子标记辅助选择。     

Detection and analysis of inter- and intraspecific diversity of Pratylenchus spp. using isozyme markers

The root-lesion nematodes of the genus Pratylenchus are an economically important group of plant parasitic nematodes that show high similarity among sibling species. Isozyme patterns obtained by isoelectrofocusing (IEF) were used to differentiate and establish genetic relatedness among Pratylenchus species. A total of 40 populations comprising 9 Pratylenchus species and Radopholus similis from broad host and geographic origins was examined to compare isozyme patterns of esterase (EST), hexoquinase (HK), isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH), phosphoglucose isomerase (PGI), phosphoglucomutase (PGM) and superoxide dismutase (SOD). Of these systems, only EST, MDH, PGI and PGM were useful for differentiation of P. vulnus , P. goodeyi , P. penetrans , P. scribneri , P. thornei and R. similis populations. The greatest intraspecific diversity was found within P. coffeae based on the isozyme patterns for MDH, PGI and PGM. Intraspecific variability was also detected among R. similis populations, which showed two isozyme patterns in EST and PGI systems. Less intraspecific variation was found within the P. penetrans group. The P. goodeyi population from Cameroon differed from the other populations in this specific group in its MDH, PGI and PGM phenotypes. Highly similar banding patterns of EST, MDH and PGI activity were found among the P. scribneri populations and the one population of P. agilis . A cluster analysis of the 40 populations, generated from the four enzyme banding patterns, produced groupings that broadly matched the previous classification into specific groups, reflecting intraspecific variability in some cases. The results confirm the potential use of isozyme patterns as markers for these nematode species and their value for diagnostic application.     

甘蓝型油菜显性细胞核雄性不育基因的AFLP标记

用甘蓝型油菜双基因显性细胞核雄性不育系Rs1046A和欧洲油菜品种Samourai构建了一个回交分离群体。在群分法（BSA）构建的不育池和可育池中共筛选了256对AFLP引物组合,找到了与不育基因紧密连锁的两个AFLP标记(EA03MC1599和EA07MC01235), 它们与不育基因的遗传图距分别是3.5 cM和5.5 cM,而且位于不育基因的同一侧,标记间相     

簇毛麦1V染色体SSR标记的筛选

选用位于普通小麦1A、1B、1D染色体上的32对微卫星引物对普通小麦中国春、簇毛麦、6个中国春-簇毛麦二体附加系和1个普通小麦-簇毛麦二体代换系进行SSR分析,发现引物Xgwm498在簇毛麦中扩增出2条长分别为110 bp和190 bp的片段（即Xgwm498/110和Xgwm498/190）, 这两个片段仅在簇毛麦、中国春-簇毛麦1Ha附加系中出现,其余2Ha、     

甘蓝型油菜人工合成种遗传多样性分析

用RAPD及SSR技术对98份甘蓝型油菜人工合成种与46份甘蓝型油菜品种(系)进行遗传多样性分析。30条随机引物共扩增出332条带,其中多态性带309条,多态性比率为93.07%。33对SSR引物共扩增出134条带,其中多态性带129条,多态性比率为96.27%。经聚类分析与主成分分析,表明甘蓝型油菜人工合成种遗传多样性十分丰富。因此通过人工     

内蒙古绒山羊产绒量和体重性状RAPD标记的初步研究

利用12条随即引物对27只内蒙古绒山羊基因组DNA进行预扩增,筛选出具有多态性扩增产物的4条引物进行RAPD分析,共得到51个标记,其中可变标记43个,标记条带多态性频率为0.84,扩增片断长度在176-2940bp之间。RAPD标记条带与经济性状关系分析表明：CY0816引物扩增产物的ABCFHO组合、F09引物的INR组合为内蒙古绒山羊产绒量的优势组合型;CY0816引物扩增产物的GIJOPQR条带组合为体重性状标记的优势组合型。     

Comparisons of RFLP and PCR-based markers to detect polymorphism between wheat cultivars

Previously chromosome 3A of wheat (Triticum aestivum L.) was reported to carry genes influencing yield, yield components, plant height, and anthesis date. The objective of current study was to survey various molecular marker systems for their ability to detect polymorphism between wheat cultivars Cheyenne(CNN) and Wichita (WI), particularly for chromosome3A. Seventy-seven `sequence tagged site' (STS), 10simple sequence repeat (SSR), 40 randomly amplified polymorphic DNA (RAPD) markers, and 52 restriction fragment length polymorphism (RFLP) probes for wheat homoeologous group 3 chromosomes, were investigated. Three (3.9%) STS-PCR primer sets amplified polymorphic fragments for the two cultivars, of which one was polymorphic for chromosome 3A. Sixty percent of SSR markers detected polymorphism between CNN and WI of which 50% were polymorphic for chromosome 3A. Twenty percent of RAPD markers detected polymorphism between CNN and WI in general, but none of these detected polymorphism for chromosome 3A. Of the fifty-two RFLP probes, 78.8% detected polymorphism between CNN and WI for group 3 chromosomes with one or more of seven restriction enzymes and 42% of the polymorphic fragements were for chromosome 3A. These high levels of RFLP and SSR polymorphisms between two related wheat cultivars could be used to map and tag genes influencing important agronomic traits. It may also be important to reconsider RFLP as the most suitable marker system at least for anchor maps of closely related wheat cultivars. This revised version was published online in July 2006 with corrections to the Cover Date.