以广东高州普通野生稻为供体亲本的水稻单片段代换系构建

以栽培稻品种粤香占为受体亲本,利用杂交、回交和微卫星标记辅助选择相结合的方法,构建了以高州普通野生稻为供体亲本的水稻单片段代换系群体。该群体由20个编号的9个单片段代换系构成。这9个单片段代换系分别分布在水稻的第1、2、3、10和11染色体上,代换片段长度为8.1～23.8cM,总长度为152.7cM,平均长度为17.0cM,代换片段对水稻基因组的覆盖总长度为136.1cM,覆盖率为7.5%。构建以高州普通野生稻为供体亲本的水稻单片段代换系,为发掘和利用高州普通野生稻的有利基因提供了理想的试验材料,为进一步开展高州普通野生稻的遗传研究提供了一条新途径。     

水稻亚种间单片段代换系的建立

利用微卫星标记辅助选择,建立了29个以台中65为受体、低脚乌尖或窄叶青为供体的单片段代换系,该代换系群体的代换片段分布于9条染色体上,总长度为643.65 cM,平均长度为22.19 cM,覆盖全基因组427.55 cM,覆盖率为23.47%。     

玉米优良自交系单片段代换系的构建

以优良自交系昌7-2为供体亲本、自交系9801为受体亲本,通过杂交、回交和供体染色体片段的SSR标记跟踪,构建以9801为遗传背景的昌7-2染色体单片段代换系群体,分析供体基因组成分在单片段代换系构建过程中的变化趋势。结果表明,共获得了74个以9801为背景的供体单片段代换系,片段长度为2.38～181.46 cM,平均长度为33.39 cM,导入片段总长为2 470.53 cM,染色体覆盖率为29%。     

基于玉米87-1综3单片段代换系的穗长QTL分析

以优良玉米自交系综3为供体、87-1为受体,利用回交和SSR标记辅助选择相结合的方法,获得了51份纯合的染色体单片段代换系(Single Segment Substitution Line,SSSL),每个SSSL内只含有一个来源于供体的染色体片段。51个代换片段不均匀分布在玉米10条染色体上,代换片段长度在1.75～172.45 cM之间,平均长度为24.44cM。覆盖玉米基因组的总长度为933.90 cM,覆盖率为40.20%。2008年在郑州利用17份SSSL材料及在三亚利用39份SSSL材料对玉米穗长进行了1年2点的表型鉴定,共检测到20个穗长QTL,加性效率百分率在-12.10%～19.18%之间。结果表明,这些单片段代换系存在较大的遗传变异,是用于玉米复杂性状的QTL鉴定、基因克隆及功能分析的理想材料。     

同源四倍体和二倍体水稻Wx基因与淀粉品质的遗传关系

用Wx 基因的(CT)n微卫星标记和切割的扩增产物多态性序列(cleaved amplified polymorphic sequence, CAPS)分子标记PCR Acc Ⅰ 对40份同源四倍体和14份二倍体水稻Wx基因型进行研究。利用484/485引物检测,Wx基因呈 Wx1、Wx2和Wx3 3种多态性;而用PCR Acc Ⅰ检测,Wx基因表现为G 型和T 型。同时,在测定稻米直链淀粉含量（AC）、胶稠度（GC）和糊化温度（GT）的基础上探讨它们与Wx基因的关系,结果表明AC、GC与Wx基因密切相关,GT与Wx基因相关不显著。综合分析表明,同源四倍体水稻中,92.0%的Wx1基因型材料为G 型,而Wx2基因型村料和800%的Wx3基因型材料为T 型。统计分析表明,Wx基因(CT)n微卫星标记检测与PCR Acc Ⅰ 分子标记检测的相关系数为0842,呈极显著正相关。     

水稻Wx基因的遗传多态性及其与主要米质指标的相关性分析

利用RM190和484/W2R ACCⅠ标记分析了50个水稻非糯品种的Wx基因的等位性变异。其中,RM190揭示出7种(CT)n纯合变异类型和1种杂合类型,分别为 (CT)20、(CT)19、(CT)18、(CT)17、(CT)14、(CT)11、(CT)10和(CT)11/(CT)18,并以（CT）11和（CT）18两种类型为主;484/W2R ACCⅠ共揭示出2种纯合类型和1 种杂合类型,分别为G/G型、T/T型及G/T型;(CT)11大多为G/G型,(CT)18大多为T/T型,这两个标记可将供试材料划分为10种等位基因变异类型。进一步分析表明,RM190揭示的Wx基因多态性可以解释直链淀粉含量变异的59.3 %;484/W2R ACCⅠ揭示的Wx基因多态性可以分别解释直链淀粉含量及胶稠度变异的56.1%和24.6%;而两标记共同可解释直链淀粉含量变异的72.4%。还对这两个标记在育种实践中的应用前景进行了探讨。     

水稻单片段代换系对两种不育细胞质恢复性的遗传分析

 由华南农业大学植物分子育种实验室选育的水稻单片段代换系S42对野败型（WA型）和夜公型（Y型）细胞质雄性不育系均具有较强的恢复性。以野败型不育系珍汕97A和Y型不育系Y华农A为母本,单片段代换系S42为父本进行杂交,采用分子标记辅助选择和连续回交的方法构建了两个BC3F2群体。利用与第1、10染色体上恢复基因Rf3和Rf4两侧紧密连锁的SSR标记,从这两个BC3F2群体中筛选携带有基因型Rf3Rf3/rf4rf4和rf3rf3/Rf4Rf4的单株,对这些单株进行花粉和小穗育性观察,并利用205个多态性SSR标记对这些单株进行遗传背景分析,结果表明： 1）在同一细胞核背景下（S42）,WA型不育细胞质的可恢复性好于Y型不育细胞质,单片段代换系S42中的恢复基因Rf4的恢复力大于Rf3; 2）单片段代换系S42中的恢复基因对于珍汕97A和Y华农A表现出质量 数量性状的遗传。在单片段代换系S42中,除了主效恢复基因Rf3和Rf4外,微效基因或者修饰基因也表现出对珍汕97A和Y华农A的育性恢复作用,而且效应较大; 3）在构建的两个BC3F2群体中,基因型Rf3Rf3/rf4rf4和rf3rf3/Rf4Rf4单株的遗传背景片段数平均为1.1,对应于恢复基因Rf3和Rf4座位的代换片段平均长度分别为14.5  cM 和17.4  cM。     

栽培稻与普通野生稻BC2F2群体产量相关性状的QTL分析

以广陆矮4号(Oryza sativa ssp. indica)为母本及轮回亲本,普通野生稻（Oryza rufipogon）为父本,分单株连续回交2次,构建BC2F2群体。首先用241对具有双亲多态性的SSR标记对BC2F1单株进行代换片段分析,在此基础上,根据BC2F1的表型选产量较优的单株自交获得BC2F2群体,用代换片段上具有双亲杂合型基因型的24对SSR标记进行QTL定位。在所选的BC2F1单株上,共检测到分布于7条染色体上的20个野生稻的代换片段,平均每条染色体上有2.86个;代换片段长度最小为0.55 cM,最大为33.00 cM,平均长度为12.36 cM,总覆盖长度为247.20 cM,覆盖率为16.21%。利用BC2F2群体对14个产量相关性状进行QTL定位,共检测到控制8个性状的20个QTL。对性状表型值起增效作用的有11个,占总检出数的55%。控制产量相关性状的QTL存在簇状分布现象,这与表型相关分析结果相符合。     

基于基因组重测序信息构建玉米第5染色体的片段代换系

利用玉米自交系齐319与郑58杂交衍生的重组自交系群体,通过筛选剩余杂合体(RHL)以达到快速构建CSSLs的目的。在接近纯合的重组自交系群体中,结合基因组重测序信息扫描玉米第5染色体上的In Del位点,定点开发分子标记,筛选剩余杂合体进行自交快速获得了多个位点的染色体片段代换系。在玉米5号染色体的19 130 718 bp~214 379 898 bp区间内,共获得41个染色体片段代换系。两个染色体片段代换系位点间的间距为0.2~26.4 Mb,平均为2.5 Mb。其中8个染色体片段代换系群体中只含有1个多态位点,为单片段代换系。本研究所建立的CSSLs可为玉米第5染色体上QTL的精细定位及功能分析提供支撑,并为玉米育种提供中间材料。     

利用分子标记鉴定四川省马铃薯品种

以15个马铃薯育成品种和引进品种为材料,采用微卫星分子标记技术鉴定供试马铃薯品种。研究检测了4个SSR位点在15份马铃薯育成品种(系)中的多态性。在15份马铃薯品种(系)中,共检测到等位基因26个,每对引物检测到的等位基因个数最少为5个,最多为10个,平均6.5个。PIC(Polymorphism information content)值最高为0.9288;最低为0.8597,平均PIC值为0.8857。仅利用少数几对高PIC值的SSR引物,即能将全部供试品种(系)区分,因此,SSR技术有利于高效准确的鉴定马铃薯品种。     

Identification of Multiple Alleles at the Wx Locus and Development of Single Segment Substitution Lines for the Alleles in Rice

Amylose content (AC) is a key determinant of the cooking and processing quality of rice (Oryza sativa). It has been reported that the amylose content is mainly controlled by the Wx locus [1]. By using RFLP analysis, two alleles, largely corresponding to t…     

Genetic Polymorphism of Wx Gene and Its Correlation with Main Grain Quality Characteristics in Rice

The allelic variation of the Wx gene in 50 non-glutinous rice varieties (lines) was analyzed by using the microsatellite marker RM190 [for (CT)n simple sequence repeat (SSR)] and cleaved amplified polymorphic sequence(CAPS) marker 484/W2R-ACCⅠ[for G/T single nucleotide polymorphism (SNP)]. Six homozygous (CT)n types, namely (CT)20, (CT)19, (CT)18, (CT)17, (CT)16, (CT)14, (CT)11 and (CT)10, and a heterozygous genotype (CT)11/(CT)18 were detected for RM190, of which (CT)11 and (CT)18 were predominant. Two homozygous Wx genotypes (G/G and T/T) and one heterozygous (G/T) were detected using 484/W2R-ACCⅠ . Most of the materials with a RM190 of (CT)11 were G/G for SNP of 484/W2R-ACC I, while T/T for SNP was predominantly appeared in materials with (CT)18. The materials tested could be grouped into 10 categories using the two markers together. Results indicated that 59.3% variance of amylose content was attributed to the polymorphism of Wx gene revealed by RM190, while 56.1% and 24.6% of the variances in amylose content and gel consistency were respectively to the polymorphism of Wx gene revealed by 484/W2R-ACC I. Furthermore, with both SSR and CAPS markers, 72.4% of the variance in amylose content could be explained. In addition, the application prospects of the two markers in breeding were also discussed.     

利用Wx和fgr基因双功能性标记高效选育优质水稻保持系

 对选取的13份籼型保持系进行直链淀粉含量和香味测定及分子标记（484/485和fgr 1F/1R）检测,筛选出宜香1B作为试验用分子育种优质供体亲本。配组Ⅱ 32B/宜香1B,F2代进行该双标记分离分析,结果表明,不仅F2单株间特异性谱带差别明显便于鉴别,且呈现出两对独立遗传基因分离模式。选取F2代 484/485和fgr 1F/1R呈Ⅰ型（与宜香B相同的带型）和Ⅲ型（杂合带型）的优良单株,经F3~F6加代,并结合农艺性状（株型、播抽历期等）和稻米品质性状（粒型、垩白度、透明度等）鉴定和选择,在F6再利用484/485和fgr 1F/1R分子标记进行复测和验证,从而获得了一批株系内性状基本稳定、株型好、直链淀粉含量中等、具有香味、外观和蒸煮食用品质优良的高世代株系。经测交鉴定,发现其保持系株系比例约占75.5%。表明利用Wx和fgr基因功能性分子标记的早世代检测和辅助选择,结合常规优质保持系鉴定和选育方法,可以快速获得直链淀粉含量中等、香味、长粒型、透明、低垩白、较易糊化等综合性状较优的保持系。     

Effects of Different Combinations of Wx and ALK Main Alleles on Rice Grain Quality

【Objective】Rice eating and cooking qualities are mainly controlled by two key genes, Wx and ALK. There are multiple alleles of both genes among rice cultivars. In this study, our aim is to clarify the effects of the main allelic variation combinations of Wx and ALK genes on rice grain quality.【Method】Three main alleles of Wx (Wxa, Wxb and wx) and two of ALK (ALKa and ALKc) were combined within a series of near-isogenic lines (NILs) in the japonica Nipponbare (Nip) background. The effects of different allelic combinations on grain quality were determined by measuring the physical and chemical characteristics of NILs.【Result】Gelatinization temperature (GT) was regulated by the major gene ALK and the minor gene Wx. Under the same ALK allele background, there was no significant difference in GT between rice lines carrying wx and Wxb alleles, but the GT of Nip-Wxa rice lines was significantly lower than that of Nip-Wxb and Nip-wx. The starch viscosity was greatly affected by the combination of Wx and ALK alleles. The breakdown value of Nip-Wxa rice line was lower and the setback value was higher (lower tasting value) than those of Nip-Wxb and Nip-wx. Under the same Wx allele background, ALK allelic variation mainly affected the pasting temperature of RVA curve, but had little effect on breakdown value and setback value. Nip-Wxa/ALKa and Nip-Wxa/ALKc rice grains had poor tasting value due to the high AC and breakdown value and low GC. But the protein content in above two NILs was higher than other rice lines. Nip-wx/ALKa and Nip-Wxb/ALka rice grains had better tasting value of hot cooked and cooled cooked rice due to the moderate AC, GC and protein content, as well as lower GT. Although the GT of Nip-Wxb/ALKc grains was higher, the moderate AC and high GC of this line resulted in a slight decrease in the tasting value of cooled cooked rice compared with hot cooked rice. The tasting value of hot cooked rice of Nip-wx/ALKc rice remained the same as those of Nip-wx/ALKa, Nip-Wxb/ALKa and Nip-Wxb/ALKc, but the tasting value of cooled rice decreased dramatically because of its high GT. 【Conclusion】Amylose content (AC) and gel consistency (GC) were mainly controlled by Wx gene; while ALK gene had no significant effect on AC, but a slight effect on GC.     

利用微卫星标记定位一个新的小麦抗白粉病基因

小麦农家品种ZB90是一个广谱抗白粉病材料.苗期和成株期鉴定表明,其白粉病抗性由显性单基因控制.从位于不同染色体上的53对微卫星引物中筛选出3对引物(Wms382、Wms311和Wms312),对144株F2分离群体进行抗病连锁性分析.另外,与Pm4a共分离的STS标记STS-470也被用于基因定位.这4个标记和抗病基因在染色体上的顺序为:基因位点-Xgwm382-Xgwm311-STS-470-Xgwm312,它们之间的遗传距离分别为2.9、4.5、23.1和49.6 cM,与小麦染色体2AL上已构建的微卫星图谱顺序一致.根据材料来源和抗病基因的染色体定位结果,确定该基因为一个新的小麦抗白粉病基因,并命名为PmZB90.文中还讨论了PmZB90和其他位于染色体2AL上的基因之间的关系.     

利用Wx基因的分子标记筛选部分糯小麦的研究

为了筛选出更多用于培育优质面条小麦的Wx基因缺失材料,用分子标记技术对260份中国核心小麦种质资源进行了分析,并用SDS-PAGE进行了验证.筛选出缺失Wx-A1蛋白亚基的品种2份,缺失Wx-B1蛋白亚基的品种14份,得到1份不同于"白火麦"的Wx-D1蛋白亚基缺失的地方品种"秃芒麦".对它们的地区分布分析发现,长江以北各麦区的小麦品种Wx基因缺失多于长江以南各麦区,且分布更为集中.对收集的20对Wx基因的分子标记引物进行了筛选,并对PCR扩增条件和产物分析条件进行优化,得到了3对可以在相同条件下对Wx基因进行筛选的引物,且能用同一电泳条件对产物进行分析,提高了分析效率.     

Potential of Waxy gene microsatellite and single-nucleotide polymorphisms to develop japonica varieties with desired amylose levels in rice (Oryza sativa L.)

The Waxy (Wx) gene is responsible for the synthesis of amylose, a key determinant of the cooking and processing qualities of rice. Polymorphisms of CT-microsatellite and G–T single-nucleotide polymorphism (SNP) in the Wx gene and their relationship to amylose content (Ac) were explored using 178 non-waxy rice genotypes. Nine Wx microsatellite alleles, namely (CT)10 and 11, and (CT)14–20 were identified and 11 haplotypes were recognised by different combinations of CT-microsatellite and G–T SNP. Amylose content analysed in a random set of 39 genotypes was correlated with different microsatellite alleles/haplotypes. The highest Ac levels (>30%) correlated with (CT)10 and 16, high (26–30%) with (CT)11, 15 and 20, and intermediate (21–25%) with (CT)14, in all cases with G at the G–T SNP. The CT-classes (CT)17 and 18 (mean Ac value of 21%), could be subdivided into low amylose haplotypes (16–20%) for 17T and 18T and intermediate amylose haplotypes (21–25%) for 17G and 18G. The use of haplotypes proved to discriminate between intermediate and low amylose accessions within the same microsatellite class. Analyses of a segregating population of a cross between low and high Ac parents showed that CT-microsatellite may help to classify breeding lines and identify pollen contamination. We suggest that CT-microsatellite together with G–T SNP may be used as molecular marker by breeders to develop varieties with desired amylose levels.     

大豆基因组中的微卫星标记

微卫星ＤＮＡ是一种简单重复序列,其核心心单位由２０－５相核苷酸组成,两侧一般 序列。由于它具有共显性,多态性高,可进行ＰＣＲ扩增分析,既简单又经济,因此是一种很有价值的分子标记。实验证明大豆的微卫星ＤＮＡ随机分布于基因组中,其核心单位主要是（ＡＴ）ｎ,（ＡＴＴ）ｎ。在人类基因组很大比例铁（ＣＡ）ｎ则很少在大豆中出现。平均每一个微卫星座位有７－１０个等位基因,最高可达２６个。大豆的微卫星标记可扩充现