水稻蒸煮品质相关QTL定位及候选基因分析

挖掘与稻米蒸煮品质相关的数量性状基因座(quantitative trait locus, QTL)，分析候选基因，并通过遗传育种手段改良稻米蒸煮品质相关性状，可有效提升稻米的口感。以籼稻华占(Huazhan, HZ)、粳稻热研2号(Nekken2)及由其构建的120个重组自交系(recombinant inbred lines, RILs)群体为实验材料，测定成熟期稻米的糊化温度(gelatinization temperature, GT)、胶稠度(gel consistency, GC)和直链淀粉含量(amylose content, AC)。结合高密度分子遗传图谱进行QTL定位，共检测到26个与稻米蒸煮品质相关的QTLs (糊化温度相关位点1个、胶稠度相关位点13个、直链淀粉含量相关位点12个)，其中最高奇数的可能性(likelihood of odd, LOD)值达30.24。通过实时荧光定量PCR (quantitative real-time polymerase chain reaction, qRT-PCR)分析定位区间内候选基因的表达量，发现6个基因在双亲间的表达量差异显著，推测LOC_Os04g20270和LOC_Os11g40100的高表达可能会极大地提高稻米的胶稠度，而LOC_Os01g04920和LOC_Os02g17500的高表达以及LOC_Os03g02650和LOC_Os05g25840的低表达有助于降低直链淀粉含量。这些结果为培育优质水稻新品种奠定了分子基础，并为揭示稻米蒸煮品质的分子调控机制提供了重要的遗传资源。     

籼粳稻杂交后代花时性状的QTL分析

研究典型籼稻品种‘七山占’和典型粳稻品种‘秋光’杂交衍生的重组自交系群体及其双亲的花时性状,并用该群体的分子连锁图谱进行QTL分析,共检测到6个与水稻花时性状相关的QTL,包括1个始花时QTL、3个盛花时QTL和2个终花时QTL,分别位于第1、2、7、8、10和12染色体,单个QTL的贡献率在7.08%～26.95%之间。有4个增效等位基因来源于粳型亲本‘秋光’,2个来源于籼型亲本‘七山占’。     

杂交粳稻品质与产量性状间的典范相关分析──杂交粳稻品质性状的遗传研究Ⅳ

由38个杂交粳稻及其12个亲本的6个产量性状和13个品质性状的典范相关分析得出：两者以稻谷重、糙米重、精米重、每穗实粒数、单株产量间相关极显著．其它性状关系小．故对产量及其余品质性状同步选择可加速育成优质高产组合．提高产量宜着力增加穗数和结实粒数,籽粒不且过大过宽过重．改良品质以糙米率、糙米长宽比、垩白率、透明度、食味最为关键,并互为正向关系,可同时改良,其中透明度、垩白率又是影响食味的主要直观性状．     

小麦籽粒品质性状的QTL分析

利用小麦中国春(母本)和兰考大粒(父本)F2群体构建了169个标记的分子遗传图谱,将F2∶3家系分别种植于3个环境中,利用基于完备区间混合模型的单环境作图模型和多环境作图模型对小麦籽粒容重、硬度、蛋白含量和结合水含量性状进行了QTL分析。结果显示:(1)两种作图模型下,检测到容重的6个共同QTL(QTW-6B-6、QTW-7B-6、QTW-7B-9、QTW-5D-2、QTW-6D-1、QTW-6D-4),单环境模型下遗传贡献率为1.99%~6.57%,多环境模型下遗传贡献率为3.66%~20.07%,其中QM TW-7B-9、QM TW-6D-1和QM TW-6D-4在多环境模型中表现为主效QTL。(2)检测到硬度的3个共同QTL(QHD-4A-5、QHD-7A-1和QHD-7B-9),单环境模型下的遗传贡献率为6.00%~6.95%,多环境模型中遗传贡献率为5.43%~9.64%。(3)检测到蛋白含量1个共同QTL(QPR-6D-1),单环境模型下的遗传贡献率为5.39%,多环境模型中遗传贡献率为10.06%,表现为主效QTL。(4)检测到籽粒结合水含量1个共同QTL(QMO-1B-4),单环境模型下的遗传贡献率为39.20%,多环境模型下的遗传贡献率为75.01%,均表现为主效QTL。(5)1B染色体上存在同时控制籽粒容重、硬度、蛋白和结合水含量的QTL,说明1B染色体对小麦品质的影响可能很大。研究表明,小麦容重、硬度、蛋白含量、结合水含量的遗传主要受加性效应控制。该研究初步定位的一些重要QTL可为进一步精细定位、基因挖掘和育种早代品质性状分子标记辅助选择提供依据。     

玉米开花期相关性状的QTL分析

利用玉米强优势组合(Mo17×黄早四)自交衍生的191个F_2单株构建了由SSR和AFLP标记组成的分子连锁图谱,用F2进一步自交产生的184个F_(2:3)家系调查散粉期、吐丝期和开花-吐丝间隔期(ASI)的表型值,采用基于混合线性模型的复合区间作图法和相应的作图软件QTLmapper/V2.0,在两个生长环境下定位了与散粉期、吐丝期和ASI相关的QTL数目分别为13、7和5个,检测到3对控制散粉期、17对控制吐丝期和5对控制ASI的上位性效应位点;同时发现了与环境存在显著互作的3个散粉期、3个吐丝期和2个ASI单位点标记区域以及1对散粉期、3对吐丝期和2对ASI上位性效应区域.对玉米散粉期、吐丝期和ASI遗传基础中遗传因素相对作用大小分析表明,加性效应、部分显性效应和上位性效应是玉米开花期相关性状的重要遗传基础.     

亚麻主要农艺与品质相关性状的QTL定位

为了全面了解亚麻产量和品质相关性状的遗传基础,为亚麻基因克隆和分子标记辅助育种提供理论依据,在已构建SNP连锁遗传图谱的基础上,以LH-89为父本,R43为母本构建F2:3家系QTL定位群体,用R/QTL软件采用复合区间作图法对13个农艺和品质性状进行QTL定位。结果表明:(1)该研究共检测出35个QTL位点,与粗脂肪及其组成成分相关的QTL有20个,与农艺性状相关的QTL有15个;其中:亚油酸和粗脂肪各5个,亚麻酸、千粒重各4个,棕榈酸、株高、工艺长度各3个,硬脂酸、分枝数各2个,单株果数、果粒数、单株粒重、油酸各1个。(2)共有18个QTL的表型贡献率超10%(主效基因),其中农艺性状定位8个主效基因,品质性状定位10个主效基因。     

云南粳稻碾磨品质性状稳定性分析

利用AMMI模型对2年5点12个粳稻品种的糙米率、精米率和整精米率进行了稳定性分析,并以碾磨品质性状的表型值及其相应的稳定性参数(Di)为指标,对供试品种进行聚类分析和评价.结果表明,糙米率、精米率和整精米率在不同品种和环境间的差异以及品种×环境互作效应均达极显著水平;碾磨品质性状的稳定性随品种和环境不同而变化较大,其稳定性顺序为糙米率>精米率>整精米率.综合考虑糙米率、精米率和整精米率及其稳定性,云粳优14号、滇元1号、云粳18号和滇元2号的碾磨品质和稳定性好,可作育种亲本,以改良水稻品种的碾磨品质及其稳定性.     

水稻光合功能相关性状QTL分析

利用粳稻Kinmaze／籼稻DV85杂交后代单粒传衍生的81个F11家系所组成的重组自交系（Recombinant Inbred Lines,RILs）群体,研究水稻光合功能相关性状的数量性状基因座（QTL）。在水稻抽穗后7d测定叶片全氮含量（TLN）、叶绿素a／b比值（Chl．a：b）和叶绿素含量（Chl）。共检测到6个QTL,各QTL的LOD值为2．66～4．81,贡献率为11．2％-29．6％,其中,在第1、2和11染色体上检测到3个与全氮含量相关的QTL,相应贡献率为17．3％、15．3％、13．7％;在第3和4染色体检测到2个与叶绿素a／b比值相关的QTL,贡献率为13．8％和29．6％;在第1染色体检测到1个与叶绿素含量相关的QTL,贡献率为11．2％。4个QTL为本研究新检测的基因座。有趣的是,控制叶绿素含量的qCC-1位于第1染色体上RFLP标记C122附近,与已报道的NADH-谷氨酸合成酶基因位置一致,而叶绿素合成始于谷氨酸,暗示该基因座与水稻光合功能关系极为密切。然而,对抽穗后30d叶绿素含量进行QTL分析,结果未检测到与其相关的QTL,表明控制叶绿素含量qCC-1效应随水稻叶片的衰老而降低。     

粳稻品质性状间及其与植株性状和产量性状间的遗传相关

利用朱军等提出的种子性状遗传模型,采用 3×3 NCⅡ正反交设计的亲本和部分组合F2代种子,分析了品质性状糙米率、垩白粒率、垩白面积和AC间及上述品质性状与株高、穗部性状等的遗传相关,以期为粳稻育种后代选择提供指导。结果表明,精米重与糙米率存在极显著的母体加性相关;虽然控制品质性状的主要遗传效应分量与植株性状相应遗传效应分量遗传协方差不显著,但在其他相应遗传效应分量方面存在着复杂的关系。     

小麦抗旱相关生理性状的QTL分析

利用RIL群体131个系,在小麦中首次对超氧化物岐化酶活性、可溶性蛋白含量、脯氨酸含量、硝酸还原酶活性、气孔导度等5个抗旱相关生理性状进行了QTL定位,共检测到超氧化物岐化酶活性、可溶性蛋白含量、硝酸还原酶活性等3个性状5个加性QTL,涉及1D、2B、5A、7B共4条染色体,可解释表型变异的8.74％～36.96％。其中．3个QTL即QSDd,sdau-7B、Qspc,sdau-1D、QNra,sdau-1D贡献率较大,分别为29.28％、23.11％和36．96％,其加性效应都源于山农483。讨论了可能用于标记辅助选择的QTL及其分子标记。     

水稻条纹叶枯病抗性位点的检测和效应分析

利用111个家系组成的热研2号（Oryza sativa subsp．japonica‘Reyan2’）／Milyang23（Oryza sativa subsp．indica‘Milyang23’）重组自交系（recombinant inbred lines,RIL）群体（F7）,采用重病区田间自然接种方法,以病情指数作为条纹叶枯病的表型值,鉴定了2个亲本及111个RIL家系对条纹叶枯病的抗性。使用QTL Cartographer软件复合区间作图法,对水稻（Oryza sativa）条纹叶枯病抗性基因进行了QTL分析。结果检测到2个抗水稻条纹叶枯病的QTL,分别位于第2和第11染色体上,其中第11染色体上的QTL贡献率为19．58％,表明这是一个主效的QTL,该QTL及其附近的分子标记,可以用于水稻条纹叶枯病抗性分子标记辅助育种。     

水稻条纹叶枯病抗性位点的检测和效应分析

利用111个家系组成的热研2号(Oryza sativa subsp. japonica ‘Reyan2’)/ Mi lyang23(Oryza sativa subsp. indica ‘Mi lyang23’)重组自交系(recombinant inbred l ines, RIL)群体(F7), 采用重病区田间自然接种方法, 以病情指数作为条纹叶枯病的表型值, 鉴定了2个亲本及111个RIL家系对条纹叶枯病的抗性。使用QTL Cartographer 软件复合区间作图法, 对水稻(Oryza a sativa)条纹叶枯病抗性基因进行了QTL分析。结果检测到2个抗水稻条纹叶枯病的QTL, 分别位于第2和第11染色体上, 其中第11染色体上的QTL贡献率为19.58%, 表明这是一个主效的QTL, 该QTL及其附近的分子标记, 可以用于水稻条纹叶枯病抗性分子标记辅助育种。     

Identification of Quantitative Trait Loci for Bacterial Blight Resistance Derived from Oryza meyeriana and Agronomic Traits in Recombinant Inbred Lines of Oryza sativa

Bacterial blight (BB) is one of the major diseases that affect rice productivity. In previous studies, BB resistance was transferred to cultivated rice Oryza sativa from wild rice Oryza meyeriana using asymmetric somatic hybridization. One of the resistant hybrid progenies (Y73) has also been shown to possess novel resistance gene(s) different from any of those previously associated with BB resistance. We have mapped quantitative trait loci (QTLs) for BB resistance in a recombinant inbred line (RIL) population derived from a cross between Y73 and a BB‐susceptible cv. IR24. Five QTLs were detected where Y73 alleles contributed to increased BB resistance. Three minor QTLs were identified on chromosomes 3, 10 and 11, and two major QTLs on chromosomes 1 and 5, respectively. QTL on chromosome 5, designated qBBR5, had the strongest effect on BB resistance, explaining approximately 37% of the phenotypic variance. Using the same RIL population, we also mapped QTLs for agronomic traits including plant height (PH), heading date (HD), plant yield (PYD) and PYD component traits. A total of 21 QTLs were identified, of which four were detected for PH, six for HD, three for panicle number per plant (PNPP), one for spikelets per panicle (SPP), six for 1000‐grain weight (TGW) and one for PYD. qPH1 (a QTL for PH) was found in the same interval as qBBR1 for BB resistance, and qHD11 for HD and qBBR11 for BB resistance also shared a similar interval. Additionally, BB resistance was significantly correlated with PH or HD in the RIL population. This suggests that the resistance genes may have pleiotropic effects on, or close linkage to, genes controlling PH or HD. These results will help deduce the resistance mechanisms of the novel resistance gene(s) and provide the basis for cloning them and using them in marker‐assisted breeding.     

水稻外观品质的数量性状基因位点分析

利用由98个家系组成的Nipponbare(粳)／Kasalath(秒)∥Nipponbare回交重组自交系(backcross inbred lines,BILs)群体(BC1F9)及其分子连锁图谱,采用复合区间作图的方法,在2个不同年份对粒长、粒宽、粒形、垩白率、垩白大小、垩白度和透明度等7个稻米外观品质性状的数量性状基因位点(Quantiative trait loci,QTL)进行了定位分析。共定位到33个四QTLs,单个性状QTL数目在4-7个之间,以垩白率最多,为7个;粒长和垩白大小次之,为5个;其他性状均为4个,表明该组合外观品质是由多基因控制的数量性状。单个QTL对性状变异解释率粒长为6．2％-15．2％,粒宽为8．3％-32．5％,长宽比为6．8％-19．8％,垩白率为6．4％-28．5％,垩白大小为6．1％-16．9％,垩白度为9．3％-17．2％,透明度为5．6％-25．2％．QTL在染色体上成集中分布的特点,第3染色体C1488-C563、第5染色体R830-R3166和R1436-R2289、第6染色体R2147-R2171均有3个以上的QTLs分布。比较2年的检测结果表明,外观品质性状的QTL定位都受环境影响,但不同性状受影响的程度差异很大。粒长和粒形的QTL定位受环境影响很小,垩白率、垩白大小和垩白度的QTL定位受环境影响很大。     

Development of Oryza rufipogon and O. sativa Introgression Lines and Assessment for Yield-related Quantitative Trait Loci

Introgression lines population was effectively used in mapping quantitative trait loci （QTLs）, identifying favorable genes, discovering hidden genetic variation, evaluating the action or interaction of QTLs in multiple conditions and providing the favorable experimental materials for plant breeding and genetic research. In this study, an advanced backcross and consecutive selfing strategy was used to develop introgression lines （ILs）, which derived from an accession of Oryza rufipogon Griff. collected from Yuanjiang County, Yunnan Province of China, as the donor, and an elite indica cultivar Teqing （O. sativa L.）, as the recipient. Introgression segments from O. rufipogon were screened using 179 polymorphic simple sequence repeats （SSR） markers in the genome of each IL. Introgressed segments carried by the introgression lines population contained 120 ILs covering the whole O. rufipogon genome. The mean number of homozygous O. rufipogon segments per introgression line was about 3.88. The average length of introgressed segments was approximate 25.5 cM, and about 20.8% of these segments had sizes less than 10 cM. The genome of each IL harbored the chromosomal fragments of O. rufipogon ranging from 0.54% to 23.7%, with an overall average of 5.79%. At each locus, the ratio of substitution of O. rufipogon alleles had a range of 1.67-9.33, with an average of 5.50. A wide range of alterations in morphological and yield-related traits were also found in the introgression lines population. Using single-point analysis, a total of 37 putative QTLs for yield and yield components were detected at two sites with 7%-20% explaining the phenotypic variance. Nineteen QTLs （51.4%） were detected at both sites, and the alleles from O. rufipogon at fifteen loci （40.5%） improved the yield and yield components in the Teqing background. These O. rufipogon-O, sativa introgression lines will serve as genetic materials for identifying and using favorable genes from common wild rice.     

Identification of Quantitative Trait Loci (QTLs) for Fruit Quality Traits in Apple

A segregating mapping population of “Co-op 17” × “Co-op 16” was used to identify quantitative trait loci (QTLs) associated with various fruit quality traits in apple. Phenotypic data were collected over 2 years for fruit circumference (in centimeter), diameter at midpoint (in centimeter), length (in centimeter), weight (in gram), total soluble solids (in degree Brix), and total titratable acids (in percent) for the segregating population. The phenotypic data along with a previously constructed genetic map, based on simple sequence repeat markers derived from expressed sequence tag and bacterial artificial chromosome end sequence databases, were used in marker–trait association analysis. Interval mapping identified two QTLs linked to fruit size components on linkage groups 03 and 05 with limit of detection scores of 3.27–4.06 and 3.29–4.02 along with phenotypic variation accounting for 15.4–46.4 and 18.3–21.9 %, respectively.     

Quantitative Trait Loci Analyses for Meristic Traits in Oncorhynchus mykiss

Meristic trait variation among species and populations has long been used as the basis for identification and classification of fishes. Within Oncorhynchus mykiss, there is considerable variation in meristic characters such as numbers of vertebrae, lateral line scales, fin rays, gill rakers, and pyloric caeca. In our laboratory the Oregon State University (OSU) rainbow trout and the Clearwater River (CW) steelhead trout clonal lines, produced by androgenesis, exhibit significant differences in values for meristic traits, making quantitative trait locus (QTL) analysis of these meristic characters possible. Our objective was to determine the number, location, and effects of QTL associated with meristic characters in order to test two hypotheses: (1) that QTL for different meristic traits co-localize to the same linkage group and (2) that meristic trait QTL co-localize to the same linkage group as a previously identified development rate QTL. Doubled haploid individuals, produced by androgenesis from sperm from an F₁ hybrid between the OSU and CW lines, were used to evaluate the joint segregation of each meristic phenotype and Amplified Fragment Length Polymorphic marker genotypes. Composite interval mapping revealed QTL for six of the seven traits analyzed. One QTL each for scales above the lateral line and for gill rakers co-localized to the same position. Only one QTL for scales above the lateral line co-localized to the same region as that for the development rate QTL, but a greater map resolution is necessary to determine if these loci are truly the same. We failed to detect pleiotropy for most meristic trait QTL. Our results suggest that different major loci are associated with variation in each meristic character and that the expression of these loci may be influenced by maternal and external environmental factors.     

粳稻穗部性状遗传分析

从粳稻（Oryzasativassp.japonica）RIL群体中选取每穗颖花数极端少的品系丙堡3201和丙堡3205及每穗颖花数极端多的品系丙堡3145和丙堡3214,配制丙堡3201×丙堡3145和丙堡3214×丙堡3205两个组合的P1、P2、F1、B1、B2和F26个世代,调查每穗颖花数、每穗实粒数、穗长、一次枝梗数和二次枝梗数的表型分布,并运用主基因＋多基因混合遗传模型,对这5个性状进行了遗传分析。结果表明,每穗颖花数性状在2个组合的各分离世代均未出现超亲分离,而其它4个性状均有不同程度的超亲分离。一次枝梗数受1对主基因＋多基因控制;其余4个性状均受2对主基因＋多基因控制。每穗颖花数、每穗实粒数、穗长和二次枝梗数4个性状以主基因遗传为主,一次枝梗数性状以多基因遗传为主。     

粳稻穗部性状遗传分析

从粳稻(Oryza sativa ssp. japonica)RIL群体中选取每穗颖花数极端少的品系丙堡3201和丙堡3205及每穗颖花数极端多的品系丙堡3145和丙堡3214, 配制丙堡3201×丙堡3145和丙堡3214×丙堡3205两个组合的P₁、P₂、F₁、B₁、B₂和F₂ 6个世代, 调查每穗颖花数、每穗实粒数、穗长、一次枝梗数和二次枝梗数的表型分布, 并运用主基因+多基因混合遗传模型,对这5个性状进行了遗传分析。结果表明, 每穗颖花数性状在2个组合的各分离世代均未出现超亲分离, 而其它4个性状均有不同程度的超亲分离。一次枝梗数受1对主基因+多基因控制; 其余4个性状均受2对主基因+多基因控制。每穗颖花数、每穗实粒数、穗长和二次枝梗数4个性状以主基因遗传为主, 一次枝梗数性状以多基因遗传为主。     

基于CSSL的水稻抽穗期QTL定位及遗传分析

抽穗期是水稻(Oryza sativa)品种的重要农艺性状之一, 适宜的抽穗期是获得理想产量的前提。鉴定和定位水稻抽穗期基因/QTL, 分析其遗传效应对改良水稻抽穗期至关重要。以籼稻品种9311(Oryza sativa ssp. indica ‘Yangdao 6’)为受体,粳稻品种日本晴(Oryza sativa ssp. japonica ‘Nipponbare’)为供体构建的94个染色体片段置换系群体为材料, 以P≤0.01为阈值, 对置换片段上的抽穗期QTL进行了鉴定。采用代换作图法共定位了4个控制水稻抽穗期的QTL, 分别位于第3、第4、第5和第8染色体; QTL的加性效应值变化范围为–6.4 – –2.7, 加性效应百分率变化范围为–6.4%– –2.7%; qHD-3和qHD-8加性效应值较大, 表现主效基因特征。为了进一步定位qHD-3和qHD-8, 在目标区域加密16对SSR引物, qHD-3和qHD-8分别被界定在第3染色体RM3166–RM16206之间及第8染色体RM4085-RM8271之间, 其遗传距离分别为13.9 cM和6.4 cM。研究结果为利用分子标记辅助选择改良水稻抽穗期奠定了基础。