小麦新品种川农16与99E18的SSR及贮藏蛋白差异分析

为了更好地识别川农16的遗传基因特性,为充分利用优异材料99E18改良川农16提供理论依据,应用简单重复序列(SSR)标记、酸性聚丙烯酰胺凝胶电泳(A-PAGE)和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)对小麦新品种川农16与高抗优质材料99E18间的遗传差异进行了检测与分析。SSR标记检测结果表明川农16与99E18在DNA水平上存在明显差异。A-PAGE分析显示川农16与99E18间至少有12条醇溶蛋白差异带。SDS-PAGE分析表明川农16和99E18的高分子量谷蛋白亚基组成分别为(1,20．5 10)和(1,7 8,5 10)。     

浙江部分茶树良种的RAPD分子鉴定

用随机扩增多态性DNA（RAPD）技术对目前浙江省推广的浙农121，迎霜，福鼎大白茶，浙农139等10个优良品种进行分析，共扩增到97条RAPD谱带636个位点，平均每个引物扩增RAPD谱带和位点约8．1条53个位咪，平均每个品种为9．7条63．6个，其中呈现出多态性的谱带72条，多态性占总带数的74．2％，供试品种经扩增产生5条－12条不等的谱带，说明引物的不同，RAPD标记谱带也随着产生差异，引物S16能在各品种扩增后产生特异性的分子标记，可以用来鉴定这些茶树品种，10个品种间遗传距离变化范围在0．3358－0．5774之间，平均为0．4732，其中浙农139和浙农113之间亲缘关系密切，类平均法聚类结果表明，这10个茶树品种可分成A、B、C三个类群。     

大豆高蛋白基因分子标记及其在大豆育种中的应用

选用高蛋白大豆黑农35和高油大豆黑农45作为亲本杂交获得F2分离群体,进行大豆高蛋白基因SSR分子标记。共筛选覆盖大豆全基因组的251对SSR引物,其中40对SSR引物在亲本间具有多态性,用这40对SSR引物分别对F2分离群体进行扩增,用Mapmaker Exp3．0和Mapmaker QTL1．1软件进行作图和定位分析。定位得到高蛋白QTL 1个,与satt532连锁,遗传距离为0．2cM,贡献率为32．7％,位于大豆公共遗传图谱的D1a＋Q连锁群。利用该引物在不同大豆材料中进行高蛋白材料检测和筛选,在56份高蛋白材料中筛选到47份,检出率达到83．93％。说明引物satt532具有一定的检测通用性,可以利用它筛选高蛋白大豆材料。     

小麦育种亲本材料遗传多样性的SSR分析

为了明确目前中国小麦育种亲本材料间的遗传关系,为育种工作提供有益信息,利用74对SSR引物对103份小麦主要亲本材料进行了遗传多样性分析,共检测出298个等位位点,每对引物等位位点数在2～14之间,平均为4.03个.位点多态信息含量(PIC)变幅为0.020～0.899,平均为0.429.品种(系)间遗传相似系数(GS)变幅为0.369～0.948,平均值为0.636.74对SSR标记能将103份小麦品种(系)分为五大类.聚类分析结果与品种系谱来源及地域比较吻合.     

玉米Ht近等基因系的RAPD、SSR分子标记比较研究

通过对玉米Ht近等基因系的RAPD、SSR分析研究,100对SSR引物中有4对引物表现差异,而100个RAPD随机引物均没有差异表现;这表明,在对玉米近等基因系进行差异研究时,SSR标记比RAPD标记更具有优越性,通过这4个SSR标记的定位结果,推测在玉米中可能具有类似小麦ph1基因作用的基因存在。     

应用RAPD分子标记分析“晚绿”品种的杂交亲本

应用随机扩增多态性DNA (RAPD)技术对茶树无性系品种“晚绿”进行亲子关系分析。所用 10 8条随机引物中的 93条引物对日本静冈和枕畸两地取样的 6个无性系茶树品种的 8份材料的基因组DNA分别扩增出 1- 8条谱带 ,平均每条引物 3 5条。其中 19条引物扩增出“晚绿”与其母本“数北”不同的RAPD分子标记 30个。从中选择 6条引物对 8份供试材料的基因组DNA鉴定表明 ,其中 4个RAPD分子标记显示出“晚绿”品种特异性 ,说明包括“静在 16”在内的 4个供试品种都不是“晚绿”的真正父本。本文还证明 ,不同生态条件下生长的同一无性系茶树品种的基因组DNA具有遗传保守性     

RAPD分子标记与小麦杂种优势相关性研究

为了给杂种小麦亲本选配提供理论依据,利用RAPD标记技术对18个杂种小麦骨干亲本进行了遗传差异分析,并结合18个亲本所组配组合的杂种优势、超亲优势和特殊配合力测定,研究了RAPD遗传标记与杂种小麦亲本优势群划分和杂种优势预测之间的相关关系。结果表明,研究选用的RAPD标记在小麦中的多态性较低,筛选了80对引物,只有15对引物在18个亲本中多态性较高;基于这15对引物的扩增结果分析,所选用的RAPD标记能进行杂种小麦亲本优势群的划分,但RAPD遗传距离与杂种小麦产量构成因素之间存在不显著的正相关关系和负相关关系。在超亲优势水平,RAPD遗传距离与穗粒数呈极显著的负相关关系,RAPD遗传距离与亲本特殊配合力之间相关性不显著。笔者认为利用本文所选用的RAPD标记不能进行杂种小麦的杂种优势预测。     

小麦亲本间分子遗传距离与F1杂种优势的相关性分析

为了探讨利用小麦亲本间分子遗传距离预测F1杂种优势的可行性，以河南省8个不同类型的小麦品种（系）为材料，分别于2003年和2004年按不完全双列杂交组配28个组合，分析与产量相关的9个性状的F1杂种优势。分别选用均匀分布于小麦21条染色体上的287对SSR引物和33个二核苷酸重复ISSR引物，计算8个亲本间的分子遗传距离．进而分析亲本间分子遗传距离与F1杂种优势表现的相关性。结果表明，SSR和ISSR两种标记估算的遗传距离间相关极显著（相关系数为0．832），表明用两种分子标记对小麦品种进行遗传差异分析的结果是一致的。除株高外，利用两种分子标记计算的亲本间分子遗传距离与F1杂种优势在全部28个组合中相关不显著，而在12个极端组合中相关系数得到较大提高，并在株高、主茎千粒重和千粒重3个性状上相关达到显著或极显著水平，且两年的研究结果一致。这说明亲本间分子遗传距离与F1杂种优势的相关性与材料的选择有关。因此认为利用小麦亲本间的SSR和ISSR遗传距离预测F1的杂种优势还需进一步研究。     

小麦抗白粉病基因Pm6的PCR标记鉴定

为了筛选出与小麦抗白粉基因Pm6连锁的PCR标记,选择位于小麦染色体2BL上的52个SSR和STS标记合成特异引物,对Pm6基因载体品种Timgalen和感病品种豫麦13及其F2代分离群体进行PCR分析,发现3个STS标记(Xwg996、KSUK948和XksuF37)和1个SSR标记(Xgwm47)与Pm6基因连锁,XksuF37、KSUK948、Pm6、Xwg996和Xgwm47五个位点之间的遗传距离分别为31.1、17.7、12.4和19.7cM.用标记Xwg996分析17个含其他抗白粉病基因的载体品种,结果表明,这个标记对Pm6基因有很强的专一性,可以应用于Pm6基因的分子鉴定和分子标记辅助育种.     

燕麦光周期不敏感基因的分子标记

为了寻找燕麦光周期不敏感基因的分子标记,本研究采用SSR及AFLP标记对来自加拿大和中国的22份燕麦材料进行了DNA指纹分析及光周期不敏感基因的分子标记研究。结果表明,所选6对燕麦SSR引物中有3对扩增出多态性高的条带,通过带型分析可以将所研究的多数燕麦品种区分开,所选的10对大麦SSR引物和4对小麦SSR引物在22个燕麦品种中多态性不高,不能将不同燕麦品种区分开来。同时利用AFLP标记对其中5个不同熟期的燕麦材料进行了分析,64对AFLP引物组合经选扩共获得18 240个条带,平均57条/引物组合。统计分析AFLP图谱,获得品种特异条带20条,可将各燕麦品种区分开。此外获得光周期不敏感燕麦品种特异条带2条,可作为燕麦光周期不敏感基因的相关分子标记。     

分子标记技术在小麦遗传育种中的应用现状

小麦庞大的基因组使得分子标记技术在小麦中的应用落后于大麦、玉米、水稻等作物。近年来,随着他子标记技术检测系统的发展和完善,分子标记技术在小麦中的应用已有了很大的进展。分子标记技术依靠提供准确、稳定可靠的ＤＮＡ水平的遗传标记,在小麦遗传育种研究中已用于构建遗传图谱、标定和定位目的基因、鉴定与标记外源染色体片段、鉴定品种真实性和纯度、绘制品种指纹图谱、遗传分析、物种演变、标记辅助选育等方面。     

小麦品种周麦22号的分子遗传基础及其特异引物筛选

国审小麦品种周麦22号具有高产、稳产、多抗和广适等突出优点,是目前全国种植面积居于前列的品种,也是优异的育种亲本材料。为研究周麦22号的分子遗传学基础以及筛选周麦22的特异引物,利用覆盖小麦全基因组的340个SSR标记对周麦22号及其亲本周麦12号、温麦6号、周麦13号进行SSR标记分析。结果表明,温麦6号对周麦22号的遗传贡献最大(37.35%),其次是周麦13号(36.14%),周麦12号贡献最小(26.51%);周麦22号和其3个亲本间的遗传相似系数的聚类结果与系谱分析不一致,表明在选育过程中亲本遗传物质的传递发生了偏分离;在不同基因组水平上,3个亲本对周麦22号的遗传贡献率差异较明显,在A、B、D三个染色体组上对周麦22号的遗传贡献各有侧重;从340个SSR标记中筛选出28个周麦22号的特异标记,并通过与周麦22号的姊妹系、相似品种、衍生品种及黄淮麦区主推的小麦品种相比较,进一步筛选出1个周麦22号的特异引物Xgwm577,建立了一种能够准确、快速、简便、稳定检测周麦22号品种真实性的检测手段,为周麦22号进一步的遗传改良和推广应用提供了理论参考。     

The correlation of genetic diversity and geographic distribution of Fusarium graminearum in North part of Iran

Fusarium Head Blight (FHB), caused mainly by Fusarium graminearum, is one of the most notorious diseases in North part of Iran. Due to lack of sufficient information regarding genetic diversity of FHB, the correlation between genetic diversity and geographic distribution of 52 isolates that collected from infected wheat kernels from four main grown region of North part of Iran were analyzed with 10 simple Sequence Repeat (SSR) primers and 15 Random Amplified Polymorphic DNA (RAPD) primers. The un-weighed pair group method using arithmetic means (UPGMA) was used and a dendrogram was constructed based on Jaccard's similarity coefficient. Principal Component Analysis (PCA) of SSR and RAPD markers revealed that the first two factors accounted for 51 and 41% of the total variance, respectively. SSR and RAPD data classified isolates into four and seven groups, respectively. SSR analysis showed that there was a correlation between genetic clusters of isolates and geographical origin in F. graminearum. However, results of cluster analysis using RAPD data didn't show any relation with geographical distribution but the results of this analysis confirmed a genetic variation among all isolates.     

A major QTL for gluten strength in durum wheat (Triticum turgidum L. var. durum)

Gluten strength is an important characteristic, determining the end product quality of durum wheat semolina. To identify the genetic basis of gluten strength in North Dakota durum cultivars, a doubled haploid population was developed from the cross of a weak gluten cultivar ‘Rugby’ and a strong gluten cultivar ‘Maier’. A framework linkage map consisting of 228 markers was constructed and used with phenotypic data on gluten strength (measured by sedimentation volume) to conduct single- and two-locus QTL analyses. Only one consistent QTL (QGs.ndsu-1B) contributing up to 90% of the phenotypic or 93% of the genotypic variation was detected on 1BS. No QTL × QTL or QTL × environment interactions were observed. The QGs.ndsu-1B was flanked by two DArT markers which were converted to STS markers and used along with SSR and EST-SSRs to develop a map of 1BS. QTL analysis delineated QGs.ndsu-1B in a 7.3 cM region flanked by an STS marker (STS-wPt2395) and a SSR marker (wmc85). The adapted background of this material and availability of PCR-based markers closely associated with this locus represent invaluable resources for marker-assisted introgression of gluten strength into other durum wheat varieties. A single QTL segregating in this population also makes it an ideal target for map-based cloning.     

小麦品种Grandin抗白粉病基因的鉴定和SSR标记

为了明确美国红粒硬质春小麦品种Grandin在小麦育种中的利用价值,对其进行了白粉病抗性基因的鉴定,并利用分子标记进行了定位.遗传分析结果表明,Grandin携带1个显性抗白粉病基因,该白粉病抗性基因与小麦SSR标记位点Xcfd81和Xcfd78连锁,遗传距离分别为0.9 cM和3.3 cM.根据小麦微卫星标记遗传连锁图以及利用中国春第5同源群双端体系对这两个SSR标记位点的定位结果,该抗白粉病基因被定位于小麦染色体5D短臂,与小麦已知抗白粉病基因Pm2的定位结果基本一致.进一步通过标记多态性比较和小麦白粉菌分小种鉴定证实Grandin所含的抗白粉病基因就是Pm2.同时还对Pm2基因的STS标记在不同群体中的实用性进行了讨论.     

Prediction criteria of promising F3 populations in durum wheat: A comparative study

Effective selection of parental material and promising segregating populations is an essential requirement for breeding success. There are many contradictive reports about the best parent selection criterion for the development of promising crosses. For the clarification of this problem field experiments were conducted for four consecutive years to compare the effectiveness of six criteria for the prediction of the most promising F₃ populations in durum wheat (Triticum durum L.): the mid-parent value, the F₁, the F₂, the (F₁ + F₂)/2, and the genetic distance among the parents as it is calculated using the SSR and RAPD molecular markers. During the first growing season (2003–2004) nine commercial cultivars of durum wheat and four landraces were crossed. The following growing season (2004–2005), 17 crosses (F₁ generation) were evaluated under low plant density (1.15 plants m⁻²) in a replicated (R-21) honeycomb design. During the third growing season (2005–2006), the four highest yielding crosses, one cross with an intermediate yield, and the three crosses with the lowest yield (F₂ generation) were evaluated under low plant density in a R-9 honeycomb design. Finally, in the fourth growing season (2006–2007) progeny of the aforementioned eight crosses (F₃ generation) and the ten parents were evaluated in a randomized complete block design in two locations. Furthermore, the genetic distance among the parents was determined using the SSR and RAPD molecular markers. It was observed that the three F₃ populations with the lowest yielding ability were the ones with the lowest mid-parental value. In addition, one of the two top F₃ populations was second in the rank according to the mid-parental value. Furthermore, the two top F₃ populations were also the highest yielding in the F₁ and F₂ generations. On the contrary, none of these crosses were predicted by the genetic distance as it was calculated using the SSR and RAPD molecular markers. It was concluded that parental pairs with high mid-parental value and high combined yield (F₁ + F₂)/2 obtained after evaluation of their F₁ and F₂ at low plant density was the most effective way to predict promising F₃ populations.     

Genetic Diversity of Tropical Hybrid Rice Germplasm Measured by Molecular Markers

Investigation of genetic diversity and relationships among breeding lines is of great importance to facilitate parent selection in hybrid rice breeding programs.In this study,we characterized 168 hybrid rice parents from International Rice Research Institute with 207 simple sequence repeat (SSR) and 353 single nucleotide polymorphism (SNP) markers.A total of 1 267 SSR and 706 SNP alleles were detected with the averages of 6.1 (SSR) and 2.0 (SNP) alleles per locus respectively across all lines.Based on the genetic distances estimated from the SSR and SNP markers separately and combined,the unrooted neighbor-joining cluster and STRUCTURE analyses consistently separated the 168 hybrid rice parents into two major groups:B-line and R-line,which is consistent with known parent pedigree information.The genetic distance matrices derived from the SSR and SNP genotyping were highly correlated (r=0.81,P < 0.001),indicating that both of the SSR and SNP markers have distinguishable power to detect polymorphism and are appropriate for genetic diversity analysis among tropical hybrid rice parents.A subset of 60 SSR markers were also chosen by the Core Hunter with 368 alleles,and the cluster analysis based on the total and subset of SSR markers highly corresponded at r=0.91 (P < 0.001),suggesting that fewer SSR markers can be used to classify and evaluate genetic diversity among parental lines.