大豆花叶病毒(SMV)株系SC4和SC8的抗性遗传分析

选用我国黄淮和长江流域大豆产区发生频繁的SMV株系SC4和SC8,利用大豆抗病材料和感病材料配制抗感和抗抗杂交组合,研究抗病材料对SC4和SC8株系的遗传方式以及不同大豆材料对SMV抗性基因位点间的等位性关系。结果表明, 接种SC4株系后,由冀LD42、徐豆1号、跃进4号、科丰1号、PI96983、晋大74、汾豆56、大白麻和齐黄22为抗源配制的9个抗感组合的F₁均表现抗病,经卡方测验, F₂抗感分离比例3∶1,F_2:3家系分离比例为1(抗)∶2(分离)∶1(感),表明这些抗源均有1对基因控制对SC4株系的抗性,且抗病表现为显性;5个抗抗组合的F₁均表现抗病,F₂群体分离比例15(抗)∶1(感),表明大白麻与汾豆56、科丰1号和齐黄1号携带抗SC4的基因是不等位的,冀LD42与汾豆56,晋大74与中作229是不等位的。接种SC8株系后,用齐黄1号、中作229、NY58、科丰1号、PI96983、晋大74、汾豆56、大白麻和齐黄22为抗源配制的抗感组合杂交后代分离符合1对基因的分离比例且F₁均表现抗病,说明这些品种对SC8株系的抗性也均由1对显性基因控制。抗抗组合晋大74×汾豆56接种SC8株系后的F₂群体全部表现抗病,F_2:3家系没有抗感分离,表明抗病品种晋大74与汾豆56携带的抗病基因是等位的;齐黄1号×科丰1号、大白麻×汾豆56的F₂群体分离比例15(抗)∶1(感),表明抗病亲本齐黄1号与科丰1号、大白麻与汾豆56携带抗SC8的基因是不等位的,而且独立遗传。     

普通小麦品种Brock抗白粉病基因分子标记定位

为明确利用Brock转育成的小麦抗白粉病品系3B529(京411*7//农大015/Brock, F₆)抗性的遗传基础,将高感白粉病小麦品系薛早和3B529杂交,获得F₁代、F₂分离群体和F_2:3家系。抗病性鉴定和遗传分析结果表明,3B529对E09小种的抗性受1对显性基因控制,暂被定名为MlBrock。利用BSA和分子标记分析,获得了与MlBrock连锁的3个SSR标记Xcfd81、Xcfd78、Xgwm159和2个SCAR标记SCAR203和SCAR112,根据SSR和SCAR标记在中国春缺体四体、双端体和缺失系的定位结果,将MlBrock定位在小麦染色体臂5DS Bin 0~0.63区间上。MlBrock与Xcfd81和SCAR203共分离,与SCAR112的遗传距离为0.5 cM。这些分子标记的建立有利于今后Brock抗白粉病基因分子标记辅助选择和基因聚合。综合抗白粉病基因MlBrock的染色体定位和抗谱分析结果,推测MlBrock很可能是Pm2基因。     

小麦品种中梁21抗条锈病基因遗传分析与SSR标记定位

用7个我国当前流行的条锈菌生理小种评价中梁21的苗期条锈抗性,结果表明该品种对我国优势流行小种具有良好的抗性。采用CYR30小种对中梁21与铭贤169杂交的F₁、BC₁、F₂及F₃代群体进行遗传分析,并利用SSR分子标记进行遗传作图,发现中梁21对CYR30的抗性由1个显性基因控制,暂命名为Yrzhong21。该基因与位于小麦5AL染色体上的10个SSR位点Xgwm186、Xbarc165、Xwmc795、Xbarc40、Xgwm156、Xgwm617、Xwmc415、Xbarc151、Xwmc338和Xgwm666连锁,其中最近的侧翼位点为Xgwm186和Xbarc165,其遗传距离分别是7.5 cM和2.7 cM。系谱分析及结合分子标记结果表明,该基因可能来自Ciemenp。与已定位于5A染色体上的抗条锈病基因的比较表明,Yrzhong21可能是一个抗条锈病的新基因。用标记Xgwm186和Xbarc165检测中梁系列品种,其中仅17%扩增到与中梁21相同的位点,表明该基因在抗条锈病育种中可能有很大的应用潜力。     

中棉所12的黄萎病抗性遗传与育种应用研究

 以2个海岛棉品种和5个陆地棉品种为材料与中棉所12进行正反交,配制14个杂交组合的F₁和F₂ 。采用纸钵育苗,撕底伤根接种方法对14个组合的F₁和F₂群体进行黄萎病抗性鉴定。结果表明,以中棉所12作父本与海岛棉抗黄萎病品种或陆地棉抗黄萎病品种进行杂交,F₂抗（耐）病株与感病株的分离符合3：1的分离规律,说明海岛棉的抗黄萎病性对于中棉所12的耐黄萎病性为显性,中棉所12的耐黄萎病性对于陆地棉的感黄萎病性为显性,控制黄萎病抗性的基因为一个显性主基因。然而,以中棉所12为母本与海岛棉品种、抗病陆地棉品种和感病陆地棉品种进行杂交,F₂群体中90%以上的个体为抗病类型,说明中棉所12的细胞质中存在着抗黄萎病的遗传成分,具有细胞质母体遗传的特点,在棉花抗黄萎病育种中具有重要的利用价值。     

利用分子标记定位普通菜豆抗炭疽病基因

为了定位中国普通菜豆的抗炭疽病基因, 选取抗炭疽病地方品种红芸豆(国家库编号F2322)与高感菜豆品种京豆(国家库编号F0777)配制杂交组合, 构建F₂抗感分离群体和F_2:3家系, 用菜豆炭疽菌81号生理小种鉴定抗病性并分析遗传性。结果表明, 红芸豆对菜豆炭疽菌81号小种的抗性是由一显性单基因控制的, 暂将该基因命名为Co-F2322。用分离群体分组分析法(BSA)和SSR、CAPs分子标记技术, 将该基因定位在B1连锁群上, 利用软件Mapmaker 3.0和Mapchart 3.0计算标记与目的基因间的遗传距离, 检测到3个SSR标记BMc32、C871、Pvm98和2个CAPs标记g1224、g683与抗炭疽病基因连锁, 遗传距离分别为26.06、3.58、13.56、3.81和12.75 cM。     

大豆粒形性状QTL的精细定位

在溧水中子黄豆×南农493-1衍生的504个F_2:6家系中选择Satt331~Satt592目标区间7个杂合单株和168个重组单株,衍生成356株RHL-F₂个体(群体I)和168个重组体家系(群体II)。群体II来自142个F_2:6家系,若每个F_2:6家系只保留1个重组家系则构成群体III。采用lasso和复合区间作图(CIM)法检测3个群体粒形性状2种指标的QTL。结果表明, lasso法检测到的粒长关联标记是O19和S21/Satt331,而CIM检测到的QTL区间是S21~S22和O23~O19;lasso法检测到的粒宽关联标记是O19/O21,而CIM检测到的QTL区间是O23~O19/O19~O21;长宽比与S21~S22关联是由于粒长QTL引起的,与O23~O19 /O19~O21关联是由于粒长和粒宽QTL引起的。将原Satt331~Satt592目标区间的粒长QTL剖分为与标记S21~S22和O23~O19/O19~O21关联的2个多效性QTL。根据大豆基因注释数据库,Glyma10g35240和Glyma10g34980可能是控制粒形性状发育的候选基因。     

玉米丝裂病的抗性QTL定位

选用感丝裂病的玉米自交系R08与抗丝裂病的自交系Es40组配F₂群体共348个单株,构建了包含115个SSR标记的分子遗传连锁图谱,覆盖玉米基因组2 178.6 cM,平均图距为18.9 cM。采用复合区间作图法,对F_2:4家系丝裂病数据进行抗性QTL分析,共检测到12个QTL,分别位于第1、2、4、5和7染色体,贡献率为4.22%~37.95%。其中在第1、3染色体上检测到主效QTL,贡献率均大于30%,基因作用方式均为显性,其余10个QTL的作用方式多为加性或部分显性。     

大豆广谱抗源对SMV优势株系的抗性遗传和等位性分析

为了研究大豆广谱抗源对我国大豆花叶病毒优势株系SC3和SC7的遗传方式及抗源材料对SMV抗性基因间的等位性关系,利用广谱抗源科丰1号和齐黄1号与感病材料南农1138-2配制抗感及抗抗杂交组合,通过人工摩擦接种法进行鉴定。结果发现,接种株系SC3和SC7后,科丰1号和齐黄1号与南农1138-2配制抗感组合的F1均表现抗病,经卡方测验,F2抗感分离比例符合3∶1,F2∶3家系分离比例为1(抗)∶2(分离)∶1(感),说明这2个广谱抗源均有1对显性基因控制株系SC3和SC7的抗性;等位性测验结果表明2个抗抗组合的F1对SC3和SC7优势株系均表现抗病,F2分离比符合15(抗)∶1(感),说明科丰1号和齐黄1号对株系SC3和SC7的抗性基因不等位且独立遗传。进一步分析2个广谱抗源携带的抗性基因可以发现,科丰1号对株系SC3的抗性基因RSC3和齐黄1号对SC7株系的抗性基因RSC7Q可能位于大豆的2号和13号染色体上,为利用大豆广谱抗源进行抗SMV育种奠定了很好的基础。     

水稻抗白叶枯病基因Xa23的RFLP标记定位及其STS标记的转化

用水稻抗白叶枯病基因Xa23的近等基因系CBB23与其感病轮回亲本金刚30（JG30）杂交，构建了包含2562个单株的F₂作图群体。用水稻白叶枯病广致病菌系P6进行抗性鉴定表明，F₂植株抗感分离比严格符合3：1。根据日本水稻基因组计划RGP水稻高密度图谱上的RFLP探针对F₂群体中的145个感病单株进行RFLP检测和连锁分析，获得了6个与Xa23紧密连锁的RFLP分子标记。其中RFLP标记C1003A靠着丝粒一侧，与Xa23的遗传图距为0.4cM，为Xa23的图位克隆奠定了重要基础。并将标记C1003A成功地转化为STS标记，为分子标记辅助选择育种（MAS）提供了方便有效的分子标记。     

水稻抗白叶枯病基因Xa14的遗传定位

Xa14是一个高抗菲律宾白叶枯病生理小种5的显性基因,Taura等将它定位在水稻第4染色体长臂末端。本研究利用中国国家基因中心的水稻第4染色体测序结果,用SSR标记对Xa14进行遗传定位,为进一步用图位克隆法克隆该基因奠定基础。利用775株IRBB14/IR24 F₂中的145株高感群体,将基因Xa14限定在SSR标记HZR970-8和HZR988-1之间的区间,与两个分子标记的距离各为0.34 cM,并找到了在该群体中与基因共分离的HZR645-4、HZR669-2、HZR669-5和HZR669-7四个SSR标记。利用763株IRBB14/珍珠矮F₂中158株高感群体,将基因Xa14限定在分子标记HZR648-5与RM280之间的区段,找到了一个与基因紧密连锁的SSR标记HZR648-5,与基因的距离为1.90 cM。将两个F₂群体的定位结果进行整合,表明Xa14位于分子标记HZR970-8和HZR988-1之间的3个BAC克隆上,并与这两个标记紧密连锁。     

Characterization of broad‐spectrum resistance to Soybean mosaic virus in soybean [Glycine max (L.) Merr.] cultivar ‘RN‐9’

Soybean mosaic virus (SMV) can cause serious yield losses in soybean. Soybean cultivar ‘RN‐9’ is resistant to 15 of 21 SMV strains. To well‐characterize this invaluable broad‐spectrum SMV‐resistance, populations (F₁, F₂ and F_2:3) derived from resistant (R) × susceptible (S) and R × R crosses were tested for SMV‐SC18 resistance. Genetic analysis revealed that SC18 resistance in ‘RN‐9’ plus two elite SMV‐resistant genotypes (‘Qihuang No.1’ and ‘Kefeng No.1’) are controlled by independently single dominant genes. Linkage analysis showed that the resistance of ‘RN‐9’ to SMV strains SC10, SC14, SC15 and SC18 is controlled by more than one gene(s). Moreover, Rsc10‐r and Rsc18‐r were both positioned between the two simple sequence repeats markers Satt286 and Satt277, while Rsc14‐r was fine‐mapped in 136.8‐kb genomic region containing sixteen genes, flanked by BARCSOYSSR_06_0786 and BARCSOYSSR_06_0790 at genetic distances of 3.79 and 4.14 cM, respectively. Allelic sequence comparison showed that Cytochrome P450‐encoding genes (Glyma.06g176000 and Glyma.06g176100) likely confer the resistance to SC14 in ‘RN‐9’. Our results would facilitate the breeding of broad‐spectrum and durable SMV resistance in soybeans.     

Molecular mapping of two recessive genes controlling resistance to bacterial leaf pustule disease in soybean (Glycine max)

Bacterial leaf pustule (BLP) caused by Xanthomonas axonopodis pv. glycines (Xag) is a serious soybean disease. A BLP resistant genotype ‘TS-3’ was crossed with a BLP susceptible genotype ‘PK472’, and a segregating F₂ mapping population was developed for genetic analysis and mapping. The F₂ population segregation pattern in 15:1 susceptible/resistance ratio against Xag inoculum indicated that the resistance to BLP in ‘TS-3’ was governed by two recessive genes. A total of 12 SSR markers, five SSR markers located on chromosome 2 and seven SSR markers located on chromosome 6 were identified as linked to BLP resistance. One of the resistance loci (r1) was mapped with flanking SSR markers Sat_183 and BARCSOYSSR_02_1613 at a distance of 0.9 and 2.1 cM, respectively. Similarly, SSR markers BARCSOYSSR_06_0024 and BARCSOYSSR_06_0013 flanked the second locus (r2) at distances of 1.5 and 2.1 cM, respectively. The identified two recessive genes imparting resistance to BLP disease and the SSR markers tightly linked to these loci would serve as important genetic and molecular resources to develop BLP resistant genotypes in soybean.     

Characterization and allelism of soybean mosaic virus strain SC3 resistance in ‘Qihuang-1’ derived soybean cultivars

Soybean mosaic virus is a severe constraint of soybean production in China. A total of country-wide 22 SMV strains (SC1-SC22) were identified. Of these, SC3 is a major strain widely distributed in Huanghuai and Yangtze River Valley region of China. Soybean cultivar ‘Qihuang-1’ contains R_SC3Q locus conditioning the resistance to SC3 and is an important parental line extensively used to breed the soybean cultivars in China. The objective of this study was to elucidate the genetic pattern of SC3 resistance genes in cultivars developed from ‘Qihuang-1’ or its derivative lines. Hence, we have evaluated the SC3 resistance in 91 cultivars developed from ‘Qihuang-1’ or its derivative lines. The results showed that a total of 43 cultivars exhibited resistance to the SC3 strain. Among them, 37 cultivars were derived from ‘Qihuang-1’. Then, we have detected the R_SC3Q loci in these cultivars using four SSR markers (Satt334, Sct_033, BARCSOYSSR_13_1114 and BARCSOYSSR_13_1136). It revealed that, among the 37 resistant cultivars derived from ‘Qihuang-1’, there are 20 cultivars containing R_SC3Q loci. Moreover, the allelic relationship of resistance genes was analysed using the crosses from resistance × resistance between ‘Qihuang-1’ and its resistant derived cultivars. The results showed that the resistance genes of ‘Qihuang-1’ and its 20 cultivars were allelic. But it is not allelic with those of the other 17 cultivars, different from ‘Qihuang-1’, and also, R_SC3Q does not condition the resistance. These results will be beneficial to exploring the transmission of resistance genes of ‘Qihuang-1’ and will be useful to the disease resistance breeding of soybean.     

Identification of the QTL underlying the vitamin E content of soybean seeds

Vitamin E (VE) is an important antioxidant supplement for human health. Soybean seed extracts are the main source of VE supplements. Therefore, increasing the VE content of soybean seeds is important issue in breeding programmes. To detect quantitative trait loci (QTL) associated with VE in soybean seeds, 238 F_6:7 recombinant inbred lines (RILs) were created by crossing a high VE cultivar, ‘Beifeng 9’, with a low VE cultivar, ‘Freeborn’. A genetic map was constructed using 218 polymorphic simple sequence repeat (SSR) markers. Composite interval mapping analysis detected 66 QTLs for contents of individual and total VE, 21 for α‐tocopherol, seventeen for γ‐tocopherol, thirteen for δ‐tocopherol and fifteen for total VE. The QTLs were located on chromosomes 9, 10, 15, 18 and 19. Phenotypic variance underlain by each QTL ranged from 2.4% to 32.6%. Two major QTLs (BARCSOYSSR_10_1140–BARCSOYSSR_10_1188 and BARCSOYSSR_15_0855 to BARCSOYSSR_15_0887) associated with α‐Toc, γ‐Toc, δ‐Toc and total VE contents were mapped on chromosomes 10 and 15. They explained 12.0% and 32.6% of phenotypic variance for α‐Toc; 5.5% and 13.0% for γ‐Toc; 6.6% and 23.6% for δ‐Toc; and 19.6% and 21.8% for total VE. QTL intervals BARCSOYSSR_15_0790–BARCSOYSSR_15_0855 (Qα15_1, Qγ15_1), BARCSOYSSR_15_1113–BARCSOYSSR_15_1159 (Qα15_3, Qδ15_2, QTVE15_4) and BARCSOYSSR_15_1159–BARCSOYSSR_15_1190 (Qα15_4, Qγ15_5, QTVE15_5) were associated with α‐Toc and explained 22.2%, 23.8% and 24.4% of the phenotypic variation in multiple environments. BARCSOYSSR_09_1098–BARCSOYSSR_09_1128 (QTVE9_1) and BARCSOYSSR_15_0887–BARCSOYSSR_15_0935 (QTVE15_2, Qγ15_3) associated with total VE content explained 21.8% and 16.4% of the phenotypic variation in two environments. These QTLs allow for marker‐assisted selection for cultivars with high VE contents.     

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。     

Genetic analysis and identification of two soybean mosaic virus resistance genes in soybean [Glycine max (L.) Merr]

Soybean mosaic virus (SMV) commonly affects soybean production worldwide, and the SC18 strain has been widespread in China. This study aimed to characterize and map the SC18 resistance genes present in soybean cultivars ‘Kefeng No. 1’ and ‘Qihuang 22’. Inheritance analysis revealed that two independent single dominant genes in Kefeng No. 1 and Qihuang 22 confer resistance to SC18. Using simple sequence repeat (SSR) markers and bulked segregant analysis, the Kefeng No. 1 and Qihuang 22 resistance genes were located on soybean chromosomes 2 and 13, respectively. We further screened two populations of recombinant inbred lines with 32 SSR markers in the target region, where the resistance gene in Kefeng No. 1 was fine mapped to an 80‐kb region containing six putative genes. Sequence and expression analyses of these genes revealed that SMV resistance in Kefeng No. 1 was probably attributable to three of the candidate genes (i.e. Glyma.02G127800, Glyma.02G128200 and Glyma.02G128300). Collectively, the results of this study will greatly facilitate the cloning of SC18 resistance genes and marker‐assisted breeding of SMV‐resistant soybean cultivars.     

大豆对SMV SC-7株系群的抗性遗传与基因定位

科丰1号×南农1138-2的P₁、P₂、F₁和180个重组自交家系接种SC-7株系群的鉴定表明,P₁与F₁全抗,P₂全感,说明抗性为显性;重组自交家系抗、感按1∶1分离,说明抗性由一对基因控制。利用王永军等的遗传连锁图对SC-7株系群的抗性基因进行连锁分析,将抗病基因Rsc-7定位于N8-D1b＋W连锁群上,并与已定位的5个抗性基因中的3个连锁,还有一个与之相连锁的标记LC5T,其排列顺序和遗传距离为Rsa (30.6 cM) Rsc-7 (22.1 cM) Rn3 (10.3 cM) Rn1 (15.8 cM) LC5T。