大豆品种豫豆25抗疫霉根腐病基因的鉴定

大豆疫霉根腐病是大豆破坏性病害之一。防治该病的最有效方法是利用抗病品种。迄今,已在大豆基因组的9个座位鉴定了15个抗大豆疫霉根腐病基因,但是只有少数基因如Rps1c、Rps1k抗性在我国是有效的。因此,必需发掘新的抗疫霉根腐病基因,以满足抗病育种的需求。豫豆25具有对大豆疫霉菌的广谱抗性,是目前筛选出的最优异的抗源。以豫豆25为抗病亲本分别与豫豆21和早熟18杂交构建F_2:3家系群体。两个群体的抗性遗传分析表明,豫豆25对疫霉根腐病的抗性由一个显性单基因控制,暂定名为RpsYD25。用SSR标记分析两个群体,RpsYD25均被定位于大豆分子遗传图谱N连锁群上。由于Rps1座位已作图在N连锁群,选择Rps1k基因中的一些SSR设计引物,检测RpsYD25与Rps1座位的遗传关系。结果表明,一个SSR标记Rps1k6与RpsYD25连锁,二者之间的遗传距离为19.4 cM。因此,推测RpsYD25可能是Rps1座位的一个新等位基因,也可能是一个新的抗病基因。     

大豆种粒斑驳抗性的遗传分析及基因定位

运用SSR标记技术及分离群体组群分析法(BSA法), 对大豆品系3C624×东农8143的F₂、F₃代群体接种SMV1号株系鉴定种粒斑驳抗性, 并进行抗种粒斑驳基因的分子定位。结果表明, 东农8143对SMV1号株系的种粒斑驳抗性受1对显性基因控制。用Mapmaker/Exp 3.0b进行连锁分析, 抗种粒斑驳基因位于大豆染色体组的F连锁群上, 并获得了与抗种粒斑驳基因紧密连锁的5个SSR标记Sat_297、Sat_229、Sat_317、Satt335和Sct_188, 标记与抗病基因间的排列顺序和连锁距离为Sat_297–12.4 cM–Sat_229–3.6 cM–SRSMV1–1.7 cM–Sat_317–2.4 cM– Satt335–13.8 cM–Sct_188。其中近距离标记Sat_229(3.6 cM)、Sat_317(1.7 cM)和Satt335(4.1 cM)可用于标记辅助选择育种和抗源筛选。     

河南大豆新品系抗大豆疫霉根腐病基因鉴定

大豆疫霉根腐病作为影响大豆生产的毁灭性病害之一,对大豆生产威胁很大。种植抗疫霉根腐病的大豆品种是控制该病害最有效的途径。河南省位于我国黄淮夏大豆产区的腹地,具有大豆疫霉根腐病发生的潜在威胁。本研究的目的是对河南省新育成的大豆品系进行抗性鉴定和抗病基因分子标记检测,以明确大豆新品系对大豆疫霉根腐病的抗性水平和抗病基因。采用下胚轴创伤接种法对64个河南省培育的大豆新品系进行接种,鉴定其对2个具有不同毒力的大豆疫霉分离物PsJS2和Ps41-1的抗性。结果显示,对分离物Ps41-1和PsJS2抗病的分别有35个和16个品系,对Ps41-1和PsJS2为中间反应型的分别有16个和10个品系,其中对2个分离物均抗病的有16个品系,占鉴定品系的25%。使用抗疫霉病基因RpsZheng共分离标记WZInDel11进行新品系的基因型鉴定发现,对2个大豆疫霉分离物均抗病的16个品系中有13个含有标记WZInDel11,对1个或2个大豆疫霉分离物表现为中间反应型的5个大豆品系,分子检测结果表明,其为杂合基因型,这些品系中的纯合抗病单株可直接选育成纯合抗病品系用于抗病育种。综合系谱分析结果推测,有2个品系可能含抗疫霉根腐病基因RpsZheng,2个品系可能含RpsYD29,14个品系可能含有RpsZheng或其等位基因。表明河南省培育的大豆新品系中含有优异的大豆疫霉根腐病抗源,该研究结果将为病害防控和抗病品种的选育提供参考。     

用AFLP标记饱和大豆SSR遗传连锁图

本研究将52个AFLP标记整合到由宛煜嵩等(2005)构建的含有227个SSR标记的大豆遗传连锁图上,绘制成一张基于SSR-AFLP标记的大豆遗传连锁图,总遗传图距为2512cM,相邻标记间的平均距离为9．0cM。AFLP标记的整合使得图谱的总图距增长了32％。在Dla、E、F、G、K连锁群上,AFLP标记主要整合在连锁群的末端,其中G连锁群尤为明显,末端增加了19个AFLP标记,使得G连锁群的长度由原来的121．2cM增加到259．1cM,相邻标记间的平均距离由原来的7．129cM变为7．197cM;在．A2、B1、C2、D2、H、J、L、N、O连锁群,由于加入了AFLP标记使得这些连锁群的标记密度有所增加,改善了标记分布的均匀性。A2连锁群上添加了1个AFLP标记,消除了1个间隙;D2连锁群上添加了2个AFLP标记,提高了原来的一个超过40cM的区间(Satt301和Satt186)标记密度;J连锁群上添加了2个．AFLP标记,消除了2个间隙。AFLP标记整合后,大多数连锁群上的SSR标记的顺序和遗传图距几乎与宛煜嵩等(2005)构建的大豆遗传连锁图上的顺序和图距一致,只有M、N和O3个连锁群上的SSR标记顺序发生了一些变化,如M连锁群上的Satt590、Satt20l和Sattl50及O连锁群上的Satt241和Satt479发生换位;N连锁群上的几个SSR标记的位置发生随机换位。我们认为构建一张理想的遗传图谱,需要来源于不同遗传背景的多种群体、多种类型的遗传标记配合。AFLP标记并非是遗传连锁图构建中常见的大区间、间隙及标记成簇分布等问题的完全解决方案,且认为AFLP标记是构建高密度的遗传连锁图的理想分子标记的看法也值得商榷。     

大豆品种郑97196抗疫霉病基因RpsZheng精细定位

大豆疫霉病是由大豆疫霉引起的一种重要大豆病害,可造成严重的经济损失。种植含有抗疫霉病基因的大豆品种是控制该病害最有效的途径。前人在大豆品种郑97196的3号染色体上鉴定了一个抗疫霉病基因RpsZheng。本研究的目的是验证幵精细定位抗疫霉病基因RpsZheng。以Williams和郑97196杂交衍生的188个F_(2:3)家系为作图群体,用大豆3号染色体上的SSR标记构建RpsZheng遗传连锁图,获得与RpsZheng紧密连锁的侧翼SSR标记SattWM82_39 (2.5 cM)和BARCSOYSSR_03_0269 (1.0 cM)。基于亲本间全基因组重测序数据鉴定和开发多态性InDel标记,进一步将RpsZheng候选区域缩小至105.2 kb,通过检测RpsZheng候选区域内的共分离标记特异性,获得了能够有效检测RpsZheng的分子标记WZInDel11。本研究明确了RpsZheng的候选基因组区间,鉴定出了能够有效用于基因功能研究和辅助选择育种的共分离分子标记。     

大豆灰斑病1号生理小种抗性基因的SSR标记

针对中国大豆灰斑病1号生理小种,以抗所有生理小种的品系东农40566为母本,以感所有生理小种的品种东农410为父本配制杂交组合,杂交得到F2代后连续自交3代得到F5代群体。该群体经人工接种灰斑病1号生理小种后,利用BSA法对500个SSR标记进行筛选,其中3个标记Satt565、SOYGPATR和Satt396在抗、感池间表现出稳定的多态性,并且在F2代个体中表现出抗性与多态性协同分离的趋势。3个标记与抗性基因的连锁顺序为Satt565—SOYGPATR—Hrcs1—Satt396,它们与抗性基因的连锁距离分别为12.7cM、6.5cM、14.7cM。推测抗大豆灰斑病1号生理小种的基因可能位于C1连锁群上。     

Rps8基因定位于大豆分子连锁群F上的抗性基因富集区

由大豆疫霉菌引起的大豆根腐病和茎腐病是大豆上的严重病害。单个显性抗性基因（Rps）以基因对基因的形式通过超敏反应调控植株对大豆疫霉菌的抗性。因其控制疫霉菌的有效性和易于被育种人员利用而受到青睐。现已报道的抗大豆疫霉病的位点有7个（Rps1至Rps7），位于大豆的4个分子连锁群上。     

大豆重组自交系群体NJRISX豆腐和豆乳得率的QTL分析

以176个家系组成的苏88-M21×新沂小黑豆重组自交系群体NJRISX为材料, 通过MAPMAKER3.0构建了包含131个SSR标记、24个连锁群的遗传图谱, 覆盖大豆基因组2 044.6 cM, 标记平均间距15.6 cM; 经2005和2006两年试验, 所获数据按主基因加多基因混合遗传模型分析干豆腐、湿豆腐和干豆乳得率的遗传机制; 应用软件Win QTL Cartographer Version 2.5复合区间作图法(CIM)和多区间作图法(MIM)检测QTL。结果显示, 在A2连锁群的Satt424~Sat_162区间检测到控制干豆腐和干豆乳得率的主效QTL各1个, qODT-A2-1可以解释15.7%~ 28.2%的表型变异, qODS-A2-1可以解释30.0%~34.8%的表型变异。检测到湿豆腐得率2个主效QTL, qOWT-A2-1位于A2连锁群的Satt424~Sat_162区间, 可以解释20.7%~30.7%的表型变异, qOWT-L位于L连锁群的Satt481~Sat_397区间, 可以解释19.0%~27.4%的表型变异。分离分析结果表明, 干豆腐和干豆乳得率均属于1对主基因加多基因遗传, 湿豆腐得率属于2对非连锁主基因加多基因遗传模型。上述QTL定位结果与分离分析所获的主基因数、贡献率及其和多基因的相对贡献可以相互验证, 建议育种中要兼顾主基因和多基因的利用。     

大豆杂种产量相关的位点及等位变异分析

选用来源于中国黄淮和美国的熟期组II~IV的8个大豆品种, 按Griffing方法II设计, 配成28个双列杂交组合, 包括8个亲本共计36份材料。选用300个SSR标记, 对8个大豆亲本进行全基因组扫描, 利用基于回归的单标记分析法, 对大豆杂种产量和分子标记进行相关性分析, 估计等位变异的效应和位点的基因型值, 剖析杂种组合的等位变异。结果表明, 300个SSR标记中有38个与杂种产量显著相关, 分布于17个连锁群上, 其中D1a和M等连锁群上较多, 有8个位于连锁定位的QTL区段内(±5 cM)。单个位点可分别解释杂种产量表型变异的11.95%~30.20%。杂种的位点构成中包括有增效显性杂合位点、增效加性纯合位点、减效加性纯合位点和减效显性杂合位点4部分, 其相对重要性依次递减。从38个显著相关的SSR标记位点中, 遴选出Satt449、Satt233和Satt631等9个优异标记基因位点, Satt449~A311、Satt233~A217和Satt631~A152等9个优异等位变异, 以及Satt449~A291/311、Satt233~A202/207和Satt631~A152/180等9个优异杂合基因型位点。这些结果为理解杂种优势的遗传构成和大豆杂种产量聚合育种提供了依据。     

一张含有315个SSR和40个AFLP标记的大豆分子遗传图的整合

本研究是基于“锚定SSR标记”作图策略,利用2个F2群体,选用592对SSR引物,对宛煜嵩等利用重组自交系群体Jinf构建的含有227个SSR标记的图谱的基础上进行整合。整合后的大豆分子遗传图包含315个SSR标记和40个AFLP标记,总图距为1951.7cM,相邻标记间的平均图距为5.48cM。整合后的遗传连锁图归属20个连锁群对应于大豆20条染色体,连锁群长度范围从40.8cM到184.4cM,标记数范围从11到41个。整合后的图谱新增加了87个SSR标记,其中A2、C1、C2、D1b和G连锁群有较多的标记增加。整合后的大豆分子遗传图谱中的标记顺序比原图谱与“公共图谱”有更好的线性符合度。本文还进一步对两种类型的作图群体的配合和不同作图软件的选用等问题进行了比较和深入的讨论。     

Modifier QTL for fatty acid composition in soybean oil

Soybean [Glycine max (L.) Merr.] is the principal oilseed crop in the world. Soybean oil has various industrial and food applications. The quality of soybean oil is determined by its fatty acid composition. Palmitic, stearic, oleic, linoleic and linolenic are the predominant fatty acids in soybean oil. The objective of this study was to determine the associations of simple sequence repeat (SSR) molecular markers with minor differences in fatty acids in soybean oil thereby detecting modifier quantitative trait loci (QTL) which could further improve soybean oil quality. To achieve this objective, 101 F₆-derived recombinant inbred lines (RIL) from a population whose parents did not contain major mutant fatty acid alleles were developed from a cross of N87-984-16 × TN93-99. Fatty acids were determined by gas chromatography. Heritability estimates on an entry mean basis for fatty acids ranged from 65.8 to 77.3% for palmitic and linoleic acids, respectively. Molecular marker Satt537 located on molecular linkage group (MLG) D1b was associated with palmitic acid and Satt168 and Satt249 located on MLG B2 and J, respectively were associated with stearic acid. Molecular markers Satt185 or Satt268 (which are within 0.6 cM of each other) located on MLG E were consistently associated with oleic and linoleic acid, and Satt263 and Satt235 located on MLG E and G, respectively were associated with linolenic acid. The lack of markers associated with multiple fatty acids suggests the possibility of independently changing fatty acid levels to achieve a desirable composition, except for regions common to all saturated fatty acids. Phenotypic variation explained by the fatty acids modifier QTL ranged from 10 to 22.5%. These modifier QTL may be useful in making minor improvements to further enhance the quality of soybean oil.     

Molecular mapping of a new gene for resistance to frogeye leaf spot of soya bean in 'Peking'

Amplified fragment length polymorphism (AFLP) and microsatellite (simple sequence repeat, SSR) techniques were used to map the _RGSp_eking gene, which is resistant to most isolates of Cercospora sojina in the soya bean cultivar ‘Peking’. The mapping was conducted using a defined F₂ population derived from the cross of ‘Peking’(resistant) בLee’(susceptible). Of 64 EcoRI and MseI primer combinations, 30 produced polymorphisms between the two parents. The F₂ population, consisting of 116 individuals, was screened with the 30 AFLP primer pairs and three mapped SSR markers to detect markers possibly linked to Rcs_Peking. One AFLP marker amplified by primer pair E‐AAC/M‐CTA and one SSR marker Satt244 were identified to be linked to Res_Peking. The gene was located within a 2.1‐cM interval between markers AACCTA178 and Satt244, 1.1 cM from Satt244 and 1.0 cM from AACCTA178. Since the SSR markers Satt244 and Satt431 have been mapped to molecular linkage group (LG) J of soya bean, the Res_Peking resistance gene was putatively located on the LG J. This will provide soya bean breeders an opportunity to use these markers for marker‐assisted selection for frogeye leaf spot resistance in soya bean.     

Quantitative trait loci for agronomic and seed quality traits in an F2 and F4:6 soybean population

Molecular breeding is becoming more practical as better technology emerges. The use of molecular markers in plant breeding for indirect selection of important traits can favorably impact breeding efficiency. The purpose of this research is to identify quantitative trait loci (QTL) on molecular linkage groups (MLG) which are associated with seed protein concentration, seed oil concentration, seed size, plant height, lodging, and maturity, in a population from a cross between the soybean cultivars ‘Essex’ and ‘Williams.’ DNA was extracted from F₂ generation soybean leaves and amplified via polymerase chain reaction (PCR) using simple sequence repeat (SSR) markers. Markers that were polymorphic between the parents were analyzed against phenotypic trait data from the F₂ and F_4:6 generation. For the F₂ population, significant additive QTL were Satt540 (MLG M, maturity, r² = 0.11; height, r² = 0.04, seed size, r²= 0.06], Satt373 (MLG L, seed size, r² = 0.04; height, r² = 0.14), Satt50 (MLG A1, maturity r² = 0.07), Satt14 (MLG D2, oil, r² = 0.05), and Satt251 (protein r² = 0.03, oil, r² =0.04). Significant dominant QTL for the F₂ population were Satt540 (MLG M,height, r² = 0.04; seed size, r² = 0.06) and Satt14 (MLG D2, oil, r² = 0.05). In the F_4:6 generation significant additive QTL were Satt239 (MLGI, height, r² = 0.02 at Knoxville, TN and r² = 0.03 at Springfield, TN), Satt14 (MLG D2, seed size, r² = 0.14 at Knoxville, TN), Satt373 (MLG L, protein, r² = 0.04 at Knoxville, TN) and Satt251 (MLG B1, lodging r² = 0.04 at Springfield, TN). Averaged over both environments in the F_4:6 generation, significant additive QTL were identified as Satt251 (MLG B1, protein, r² = 0.03), and Satt239 (MLG I, height, r² = 0.03). The results found in this study indicate that selections based solely on these QTL would produce limited gains (based on low r² values). Few QTL were detected to be stable across environments. Further research to identify stable QTL over environments is needed to make marker-assisted approaches more widely adopted by soybean breeders. This revised version was published online in July 2006 with corrections to the Cover Date.     

Molecular mapping of a fertility restorer gene for cytoplasmic male sterility in soybean

In this study, we report the mapping of the Rf locus in soybean by microsatellite simple sequence repeat (SSR) genetic markers. A cross was made between cytoplasmic male sterility (CMS) line JLCMS82A and restorer line JIHUI 1 based on the DNA polymorphisms revealed by 109 SSR markers. A F₂ population derived from a single F₁ plant containing 103 individuals was used for mapping the Rf locus. The Rf gene of JIHUI 1 gametophytically restores male fertility to JLCMS82A. Fertile and semi-fertile DNA bulks and parental DNAs were screened with 219 SSR markers, and Satt215 which was previously mapped to soybean LG J, was found linked to the Rf gene. Five additional polymorphic SSR markers from LG J were used for analysis and a regional linkage map around the Rf locus was established. SSR markers, Sctt011 and Satt547, flanked the Rf locus at 3.6 cM and 5.4 cM, respectively. The availability of these SSR markers will facilitate the selection of restorer lines in hybrid soybean breeding.     

A quantitative trait locus influencing tolerance to Phytophthora root rot in the soybean cultivar ‘Conrad’

‘Conrad’, a soybean cultivar tolerant to Phytophthora root rot (PRR), and ‘OX760-6-1’, a breeding line with low tolerance to PRR, were crossed. F₂ derived recombinant inbred lines were advanced to F₆ to generate a population through single-seed descent. This population was used to identify quantitative trait loci (QTLs) influencing PRR tolerance in ‘Conrad’. A total of 99 simple sequence repeat (SSR), or microsatellite, markers that were polymorphic and clearly segregated in the F₆ mapping population were used for QTL detection. Based on the data of PRR in the field at two planting locations, Woodslee and Weaver, for the years 2000 and 2001, one putative QTL, designated as Qsatt414-596, was detected using MapMaker/QTL. Qsatt414-596 was flanked by two SSR markers from the linkage group MLG J, Satt414 and Satt596. Satt414 and Satt596 were also detected to be significantly (P < 0.005) associated with PRR using the SAS GLM procedure and were estimated to explain 13.7% and 21.5% of the total phenotypic variance, respectively.     

Identification of SSR markers linked to the Phytophthora resistance gene Rps1-d in soybean

To identify markers for the Phytophthora resistance gene, Rps1‐d, 123 F_{2 : 3} families were produced from a cross between Glycine max (L.) Merr. ‘Tanbakuro’ (a Japanese traditional black soybean) and PI103091 (Rps1‐d) as an experimental population. The results of virulence tests produced 33 homozygous resistant, 61 segregating and 29 homozygous susceptible F_{2 : 3} families. The chi‐squared test gave a goodness‐of‐fit for the expected ratio of 1 : 2 : 1 for resistant, segregating and susceptible traits, suggesting that the inheritance of Rps1‐d is controlled by a monogenic dominant gene. Simple sequence repeat (SSR) analyses of this trait were carried out using the cultivars ‘Tanbakuro’ and PI103091. Sixteen SSR primers, which produced 19 polymorphic fragments between the two parents, were identified from 41 SSR primers in MLG N. Eight SSR markers were related to Rps1‐d, based on 32 of the 123 F_{2 : 3} families, consisting of 16 homozygous resistant and 16 homozygous susceptible lines. The remaining 91 families were analysed for these eight markers, and a linkage map was constructed using all 123 F_{2 : 3} families. The length of this linkage group is 44.0 cM. The closest markers, Sat_186 and Satt152, are mapped at 5.7 cM and 11.5 cM, respectively, on either side of the Rps1‐d gene. Three‐way contingency table analysis indicates that dual‐marker‐assisted selection using these two flanking markers would be efficient.     

大豆主茎节数数量性状座定位及遗传效应分析

为了定位控制主茎节数的QTL并明确其遗传效应,利用100对SSR引物,并采用Mapmaker Exp 3.0和复合区间法,研究构建了一张包括3个连锁群的连锁图谱。以‘黑农37’（栽培大豆）×ZYD581（野生大豆）组合的亲本、F₂、F₃为试材,分别在chr1连锁群上定位了一个影响大豆主茎节数的QTL,2007年QTL位于Satt238—Satt242这个区间内,与Satt238的遗传距离是0.01 cM,与Satt242的遗传距离是24.69 cM,其遗传贡献率为17.22%,加性效应为-3.2608;2008年QTL位于Satt238—Satt240之间,与Satt238的遗传距离为0.59 cM,与Satt240的遗传距离为6.01 cM,其遗传贡献率为6.68%,加性效应为-1.4965。2年大豆主茎节数QTL分析表明,在chr1连锁群上Satt238附近确定了1个控制大豆主茎节数QTL位点。