区试水稻品种的Pi-km基因的分析

稻瘟病抗性基因Pi-km是稻瘟病抗性位点Pik上的一个主效抗病等位基因,由两个紧密连锁的具有独立功能的NBS-LRR类基因(Pikm1-TS和Pikm2-TS)组成,Pi-km基因介导的稻瘟病抗性需要Pikm1-TS与Pikm2-TS所编码的蛋白共同作用,而当只有Pikm2-TS或Pikm1-TS其中之一时,水稻则表现为感性。实验利用抗稻瘟病基因Pi-km的Indel分子标记设计引物,对2012年62份长江上游国家水稻区域试验材料和97份2012年陕西省水稻区域试验材料进行Pi-km基因型分型研究,以期为稻瘟病抗性育种提供参考。     

籼稻品种地谷抗稻瘟病基因的遗传分析和定位

利用我国稻区的稻瘟病生理小种ZB₁₃和ZB₁₅对地谷与感病品种江南香糯的杂交F₁,F₂和B₁F₁群体进行接种鉴定,确认地谷对ZB₁₃和ZB₁₅的抗性受一对显性基因控制．应用ZB₁₃接种的(地谷×江南香糯)F₂群体构建抗病池和感病池,通过RFLP和微卫星标记对两池DNA多态性的检测,发现两个可能与相应抗病基因紧密连锁的分子标记．进一步用F₂分离群体,将该基因定位于第2染色体,暂定名为Pi-d(t)．     

中国小麦周8425B/中国春RIL群体成株抗叶锈基因的QTL定位

为确定小麦叶锈病抗病基因的QTL检测及定位,找到能与抗病基因紧密连锁的分子标记,以小麦品种周8425B,中国春及其杂交获得的244个F_(2∶8) RIL群体为试验材料,分别于2014～2015年在河北保定和河南周口进行了田间叶锈病病害严重度调查,获得了群体的表型数据,利用SNP标记和SSR标记进行基因分型,得到了群体基因型数据,运用软件Joinmap和QTL Ici Mapping 3.1进行连锁作图和QTL定位。结果找到2个QTL位点,分别位于2B,7D染色体上。     

4个小麦品种的抗白粉病遗传分析

抗病品种郑315、CP87-26-12和91138-16-2-13-12,与感病品种豫麦49号杂交的F1代表现抗病,F2代抗、感单株的分离比例为31,表明这3个品种均携带1对显性抗病基因.N97189-2和豫麦18号的杂交F1代对白粉病表现高感,F2代抗、感单株的分离比例为13,由此推断N97189-2对白粉病的抗性由1对隐性基因控制.     

辣椒矮化性状的遗传分析、初步定位及SSR标记筛选

目的 明确辣椒矮化性状的分离规律,筛选与之紧密连锁的分子标记,为开展辣椒矮化性状的MAS育种奠定基础。方法 以辣椒矮化种质SSI9024a和无限生长型种质杭椒为试材,分别比较了2个种质7个农艺、品质性状,并构建了4世代分离群体,通过BSA混池测序对该性状进行初步定位,并筛选了与之紧密连锁的SSR分子标记。结果 在株高、果长、果宽、单果重4个农艺性状指标中,杭椒都显著优于SSI9024a亲本,而后者在V_C含量上是前者的6倍多。遗传分析表明,矮化性状受单个隐形基因控制,BSA测序将该基因定位在第6号染色体上,通过对回交后代单株进行验证,引物HpmsE002与矮化性状紧密连锁。结论 成功解析了辣椒矮化性状的遗传规律,并获得了与之紧密连锁的分子标记,这对其后续的MAS育种提供了参考依据。     

一个水稻抗纹枯病突变体的遗传分析及其基因的初步定位

高水平抗纹枯病突变体和高感纹枯病品种蜀恢881杂交构建分离群体,经F2分离世代的遗传分析,抗、感单株比例符合3 1(χc2=0.563,χ12,0.05=3.84),初步确定该突变体对纹枯病的抗性由一对显性主效基因所控制,命名为Rsb-2(t)。利用已合成的530对微卫星引物,对抗纹枯病突变体和蜀恢881进行多态性引物筛选,用多态性引物对上述F2分离群体的全部感病单株和部分抗病单株的DNA进行PCR分析,借助MAPERMAKER/EXP3.0软件,对其微卫星标记实验数据进行连锁分析,将Rsb-2(t)定位于第3染色体的p臂,发现RM218、RM251、RM4321和RM5748与Rsb-2(t)连锁,它们均位于着丝粒端,连锁距离分别为32.1 cM,41.1 cM,42.4 cM和49.7 cM。研究结果为进一步对该基因的精细定位奠定了基础。     

大豆基因组F连锁群较高密度图谱的构建和基因定位

应用栽培大豆"长农4号"和半野生大豆"新民6号"杂交得到的F8代重组自交系(88株)构建了较高密度的大豆F连锁群图谱.该连锁群包括5个限制性片段长度多态性(RFLP)标记,7个扩增片段长度多态性(AFLP)标记,14个微卫星(SSR)标记和1个形态学标记,标记之间的平均距离为11.8 cM,连锁群总长度为331.7 cM.大豆的紫花/白花基因(w)定位在该连锁群上,与花色基因连锁的两个标记为Satt03911.0 cMw 16.7 cM Satt516.作图分析中发现其中一个RFLP标记(K14)有4个独立分离的等位基因,其中两个(K14-2和K14-4)定位在该连锁群上,并且紧密连锁,反映了大豆基因组的复杂性.     

利用AFLP-银染法筛选与抗甘蓝黑腐病性状连锁的分子标记

利用ＡＦＬＰ－银染法在一对花椰菜抗、感黑腐病的近等基因系中筛选到四个与抗黑腐病性状、一个与感黑腐病性状连锁的ＤＮＡ 分子标记．对其中一个４００ｂｐ 的抗病标记进行Ｓｏｕｔｈｅｒｎ 杂交检测,结果表明该标记在抗病品系中存在明显的杂交信号,而在感病品系中无杂交信号．该标记测序后,通过Ｇｅｎｂａｎｋ 进行同源性检测,发现其与拟南芥菜ＢＡＣ克隆Ｆ７Ｎ２２ 部分序列有７５％ 的同源性．该ＢＡＣ克隆位于拟南芥菜５ 号染色体的黑腐病抗性基因（ｒｘｃ２）附近．这意味着该标记可能与甘蓝黑腐病抗性基因紧密连锁．     

水稻早熟基因显性抑制基因的遗传分析和分子标记定位

将明恢63，9311，IR68，献国和BG1639等5个迟热水稻品种与早籼核不育系6442S—7杂交，对F1，F2代以及三交F1群体进行抽穗期遗传分析．结果表明，9311，IR68，献国和BG1639等4个迟熟品种含有1对等位的显性抑制基因，可部分地抑制6442S—7显性早熟基因的表达．以6442S—7∥明恢63／9311三交F1群体为定位群体，利用微卫星标记将该抑制基因定位于水稻第8染色体短臂上．该抑制基因命名为Su—Ef-cd(t)，并认为该基因对于利用6442S—7早熟基因来培育不同熟期的早熟和中早熟品种具有重要意义．     

绵羊ZBED6基因多态性检测及群体遗传结构分析

为了明确绵羊ZBED6基因的分子遗传特征及其在群体间的差异,采用DNA快速测序法对特克赛尔羊与阿勒泰羊杂交后代进行多态性检测,为下一步分析该基因与产肉性状的相关性奠定基础,进而为绵羊产肉性状的选育提供分子标记。结果显示:2个杂交群体在ZBED6基因编码区均存在两处多态性位点,2个位点发生的突变分别是位于第一外显子1723 bp的C→T突变和位于第一外显子2095 bp的A→G突变。这2个突变未导致氨基酸变化,为同义突变;经卡方检验分析,在C1723T位点,基因型TT在横交F2和回交F2群体中均表现为优势基因型,且T等位基因在2个群体中均为优势等位基因;2个群体的有效等位基因数接近2,说明此等位基因在群体中分布均匀;横交F2、回交F2绵羊多态信息含量分别为0.38、0.36,为中度多态,遗传变异较大;2个群体的基因型分布不存在差异(P0.05)。在A2095G位点,基因型AG在2个群体中表现为优势基因型,A等位基因为优势等位基因,且分布均匀;2个群体PIC为0.36(横交F2)、0.40(回交F2),呈中度多态,基因型分布亦不存在差异。这表明在ZBED6基因上检测到的2个多态性位点与供试绵羊群体基因型分布差异不显著。     

Mapping of two new brown planthopper resistance genes from wild rice

A brown planthopper (BPH) resistance line, B5, derived its resistance genes from the wild riceOryza officinalis Wall exwatt, was hybridized with Taichung Native 1, a cultivar highly susceptible to BPH. A mapping population composed of randomly selected 167 F₂ individuals was used for determining the BPH resistance genes by the restriction fragment length polymorphism analysis (RFLP). Bulked segregant analysis was conducted to identify RFLP makers linked to the BPH resistance genes in B5. The results indicated that the markers linked to BPH resistance are located at two genomic regions on the long arm of chromosome 3 and the short arm of chromosome 4, respectively. The existence of the two loci was further assessed by the quantitative trait locus (QTL) analysis. We located the two loci at a 3.2 cM interval between G1318 and R1925 on chromosome 3 and a 1.2 cM interval between C820 and S11182 on chromosome 4. Comparison with the BPH genes that have been reported indicated that the BPH resistance genes in B5 are novel. These two genes may be useful BPH resistance resource for rice breeding. Furthermore, the mapping of the two genes is useful for cloning the BPH resistance genes.     

上海市11种常规粳稻抗稻瘟病基因分子标记检测

利用分子标记检测技术,对9种参加2020年上海市水稻区域试验的品种和2种本课题组新培育的新品系的共10个抗稻瘟病基因位点进行了检测.结果显示,Pi37,Pi41,Pi-d23个基因在11种水稻中出现的频率达100％,Pi2,Pi5,Pi9,Pi36,Pikm和Pib抗性基因在11种水稻中出现的频率分别为18.18％,9...     

Cytogenetic Mapping of Disease Resistance Genes and Analysis of Their Distribution Features on Chromosomes in Maize

0　IntroductionMaizeisamongthemostintensivelystudiedspeciesingeneticsandoneofagronomicallythemostimportantplants.Therearemanydis easemicrobesandpeststoattackmaize,whichre sultsinlowproductionandbadquality .Withthedevelopmentofverydensegeneticmapconstruc tion ,avarietyoftheimportantdiseaseresistancegenesofmaizeincludingHelminthosporiumtur ciumPassresistancegenesHt1,Htn1andHt2 ,HelminthosporiummaydisNisikresistancegenesRhm1andRhm2 ,maizedwarfmosaicvirusresis tancegeneMdm1,wheatstreakmosaicvi…     

水稻光温敏雄性不育基因连锁标记的分离与鉴定

两系法杂交稻是一种利用水稻杂种优势的重要途径，主要依据水稻光温敏雄性不育系在不同条件下的育性转换用于配制杂交种．以培矮64S(PTGMS)与明恢63杂种自交的F2代为供试材料，采用随机放大多态性DNA(RAPD)技术分离与培矮64S的PTGMS基因连锁的分子标记．在F2代2个分别代表可育和不育的群体以及亲本株系中，采用100个RAPD引物扩放基因组DNA筛选多态性DNA片段．RAPD引物S8产生的DNA片段中，除重复顺序外，有一个长度为0．85kb片段为单拷贝．分子杂交表明，这一单拷贝标记与培矮64S的PTGMS基因连锁．     

Genome-wide identification of R genes and exploitation of candidate RGA markers in rice

By scanning the whole genomic sequence of japonica rice using 45 known plant disease resistance (R) genes, we identified 2119 resistance gene homologs or analogs (RGAs) and verified that RGAs are not randomly distributed but tend to cluster in the rice genome. The RGAs were classified into 21 families according to their functional domain based on Hidden Markov model (HMM). By comparing the RGAs of japonica rice with the whole genomlc sequence of indica rice, we found 702 RGAs allelic between the two subspecies and revealed that 671 (95.6%) of them have length difference (InDels) in their genomic sequences (including coding and non-coding regions) between the two subspecies, suggesting that RGAs are highly polymorphic between the two subspecies in rice. We also exploited 402 PCR-based and co-dominant candidate RGA markers by designing primer pairs on the regions flanking the lnDels and validating them via e-PCR. The length differences of the candidate RGA markers between the two subspecies are from 1 to 742 hp, with an average of 10.26 hp. All related information of the RGAs is available from our web site(http://ibi.zju.edu.cn/RGAs/index.html).     

Genetic and physical mapping of AvrPi7, a novel avirulence gene of Magnaporthe oryzae using physical position-ready markers

Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most devastating crop diseases worldwide. The avirulence gene corresponding to rice blast resistance gene Pi7 in field isolate CHL346 was inherited as a single gene, designated AvrPi7, in a segregating population consisting of 189 ascospore progenies derived from a cross between field isolates CHL346 and CHL42. In order to determine the chromosomal location of the AvrPi7 locus, a total of 121 simple sequence repeat (SSR) markers were developed based on the whole-genome sequence of reference isolate 70-15 of M. oryzae. Linkage analysis of the locus with these SSR markers showed that eight SSR markers on chromosome 1 were linked to the locus, among which the closest flanking markers MS1-9 and MS1-15 were 3.2 and 16.4 cM from the locus, respectively. For fine mapping, additional PCR-based makers including eight SSR markers and three candidate avirulence gene (CAG) markers were developed in the region flanking both markers. The AvrPi7 locus was genetically delimited within a 1.6-cM region flanked by markers MS1-21 and MS1-22, and co-segregated with the marker CAG2. To construct a physical map of the AvrPi7 locus, molecular markers linked to the Avr gene were mapped on the supercontigs of the ref-erence isolate 70-15 through bioinformation analysis (BIA). Consequently, the AvrPi7 locus was delim-ited to a 75-kb interval flanked by markers MS1-21 and MS1-22 based on the reference sequence. Merodiploids observed in this study are also discussed.     

Physical location of the ricePi-5(t), Glh andRTSV genes by ISH of BAC clones

Mapping of low or single-copy sequences on plant chromosomes has proven difficult because of very low frequency of signal detection. Rice BAC library is being used widely in rice genome research due to its distinctive advantages over other library systems. In this study, two biotin-labeled rice BAC clones closely linked to a rice blast resistance, green leafhopper resistance and tungro spherical virus resistance gene,Pi-5(t), Glh, RTSV, werein situ hybridized to rice chromosomes. They were located on the long arm and short arm of chromosome 4 with FL value of 40% and 100% respectively. The frequency of signal detection reached 46.8% and 59.2%. The signal location were consistent with the selective marker on rice saturated molecular map. The results demonstrated the advantages to locate BAC clones to chromosomes byin situ hybridization and will facilitate the rice low or single-copy gene location by using the BAC library. Supported by the National Natural Science Foundation of China and the Doctorate Vesting Point Foundation of the Education Department of the People's Republic of China Yan Huimin: born in 1964, Lecturer     

Analysis of rice blast resistance genes by QTL mapping

Resistance to rice blast pathogen mostly shows a quantitative trait controlled by several minor genes. Its complexity and the mutable characteristic of rice blast isolates both hinder the development of the blast resistance research. The article here tried to explore the resistance gene distribution on rice chromosomes and the way of function. Totally 124 QTLs have been identified against 20 isolates using Cartographer software with a ZYQ8/JX17 DH population, which separately are at 100 loci of 72 marker intervals on 12 rice chromosomes. Of them, 16 QTLs were determined by the isolate HB-97-36-1. 82 QTLs (66.13%) are from the resistant parent alleles, ZYQ8, while 42 QTLs (33.87%) are from the susceptible parent alleles, JX17. In comparison of their positions on chromosome, most QTLs are clustered together and distributed nearby the major genes especially the regions on chromosomes 1, 2, 8, 10 and 12. Each QTL could account for the resistance variation between 3~2%-68.64%. And, a positional QTL might display the resistance to several different isolates with different contributions.