普通菜豆基因组学及抗炭疽病遗传研究进展

普通菜豆是重要的食用豆类之一,在世界各大洲普遍种植。近年来,普通菜豆在遗传图谱构建、新标记开发与利用、抗性基因定位以及比较基因组学等方面取得了很大进展。遗传连锁图谱的构建是基因定位与克隆的基础,是遗传研究中的重要内容;利用分子连锁图谱鉴定、标记和定位抗病基因将在种质改良和分子标记辅助育种方面发挥重要作用。豆科植物比较基因组学的研究成果为菜豆遗传连锁图谱的发展提供了新的思路。本文从普通菜豆遗传连锁图谱的获得、普通菜豆与大豆同线性比较以及抗炭疽病基因定位等方面进行了综述,以期为普通菜豆遗传改良和抗病育种提供参考。 关键词：普通菜豆;遗传连锁图;同线性比较;抗菜豆炭疽病     

梨遗传连锁图谱的构建及其与苹果图谱的比较

以‘丰水’为母本、‘砀山酥梨’为父本杂交所得的F1代104株单体为作图群体,利用SSR分子标记进行遗传连锁分析,应用Jionmap 3.0作图软件,构建了一张包含104个SSR分子标记,分属于18个连锁群的梨遗传连锁图谱,覆盖梨基因组总长831.8cM,平均图距为8.0cM。根据定位到该图谱上的SSR标记与苹果‘Fiesta’图谱进行比较,25个共有的SSR标记将该图谱和苹果图谱各连锁群连接起来,这些标记不仅呈现良好的共线性而且它们之间的相对遗传距离也很相近。研究认为,SSR标记作为锚定引物,可以与不同物种的遗传图谱相比较整合,为不同物种之间遗传信息的转移提供参考依据;同时该研究为梨树相关性状的基因定位、分离以及克隆奠定了基础。     

三色堇与角堇种间遗传连锁图谱构建

该研究以二倍体三色堇和角堇为亲本杂交产生的66株F2代分离群体为作图群体,采用SRAP标记技术进行基因分型,利用JoinMap4.0软件构建了首张三色堇与角堇的种间遗传连锁图谱。结果表明:(1)从256对SRAP引物组合中筛选获得50对多态性好、标记位点清晰且稳定的引物组合。(2)通过对三色堇F2代群体的PCR扩增,共获得118个SRAP多态性标记位点,其中偏分离标记率为24.6%,符合遗传作图需要。(3)成功构建了三色堇和角堇的种间分子遗传连锁图谱,该图谱有15个连锁群,67个SRAP标记,连锁群长度范围1.6~52.2 cM,覆盖基因组总长度327.9 cM,标记间平均图距为4.9 cM。研究结果为三色堇和角堇高密度遗传图谱构建和重要性状的基因定位及分子标记辅助选择育种奠定了基础。     

基于SRAP分子标记的冰草遗传连锁图谱构建

构建高密度遗传连锁图谱是冰草抗性、品质、产量等重要性状QTL精细定位及标记辅助育种研究的基础。该试验以四倍体杂交冰草F2群体的202个分离单株及其亲本为材料,利用SRAP分子标记技术和Join Map 4.0作图软件对冰草的遗传连锁图谱进行了构建。结果表明:(1)共筛选出22对多态性好、标记位点清晰稳定的SRAP适宜引物,对冰草杂种F2分离单株的基因组DNA进行PCR扩增,共获得510个SRAP多态性标记位点,其比率占88.2%。(2)偏分离分析表明,偏分离标记比率仅为14.12%,符合遗传作图的要求。(3)成功构建了冰草的SRAP分子标记遗传连锁图谱,该图谱有14个连锁群、510个标记,连锁群间长度范围86.4～179.0cM,覆盖基因组总长度1 912.9cM,标记间平均间距3.75cM,为高密度遗传图谱。     

分子标记在绿豆遗传连锁图谱构建和基因定位研究中的应用

绿豆(Vigna radiata(L.)Wilczek)作为一种医食两用作物,不仅是重要的食物资源,在改善土壤环境、提高农民收入等方面也发挥着重要作用。然而,相对于大宗作物而言,绿豆基础研究薄弱,基因组研究更是落后。近年来,分子标记技术迅速发展,在绿豆基因组学研究中发挥了重要的作用。国内外利用分子标记技术已构建了超过20张绿豆遗传连锁图谱。一些优良基因尤其是与抗性相关的基因被鉴定或精细定位,为绿豆分子标记辅助选择打下基础,加快了抗性新品种的培育进程。本研究通过对分子标记技术在绿豆遗传连锁图谱构建、重要功能基因的定位等方面的应用进行综述,以期为绿豆遗传育种研究及功能基因组学分析提供参考。     

水稻籼粳交F2、F6群体遗传连锁图谱的比较分析

以部分基因组和全基因组测序水稻籼稻(O sativa L. indica)品种“培矮64S”(Pei’ai 64S♀)和粳稻(O sativa L. japonica)品种“日本晴”(Nipponbare♂)为构图亲本, 选取F2代180个株系为作图群体, 构建含138个微卫星位点的水稻遗传连锁图谱, 覆盖基因组2 046.2 cM, 平均图距17.1 cM, 即F2 图谱; 采用单粒传法获得F2:6 代330个株系, 用相同的多态性标记分析F6群体, 构建含92个标记连锁图谱, 覆盖基因组2 563.5 cM, 平均图距27.86 cM, 即F6图谱; F2、F6图谱在连锁群数、定位标记数、标记的位置顺序、遗传图距、平均图距等方面发生了较大变化, 并对产生这些差异的原因进行了初步分析。     

对家蚕第18连锁群隐性基因elp、ch-2和mln测交系的分子定位分析

家蚕长形卵(elp)、第二隐性赤蚁(ch-2)、暗化型(mln)均为第18染色体上的隐性突变, 在经典连锁图谱上的顺序和遗传距离已经排定。文章采用正常卵、正常黑蚁及正常白蛾品种P50与包含此3个隐性突变的三隐性测交系W18组配正反交群体, F1回交W18后获得回交群体(P50×W18)♀×W18♂ 和W18♀×(P50×W18)♂, 分别记作BC1F和BC1M, 利用已构建的家蚕SSR分子连锁图谱和根据家蚕基因组精细图设计的STS标记, 对这3个突变基因elp、ch-2、mln进行了分子定位研究, 并根据家蚕基因组精细图, 将第18连锁群的经典遗传图、分子连锁图和基因组物理图进行了对应。整合后的图谱遗传距离为94.2 cM, 突变基因和分子标记的排列顺序分别与形态标记连锁图和基因组精细图相一致, 研究结果对家蚕第18 染色体上其他突变的定位与克隆有重要的借鉴作用。     

玉米相对饱和遗传连锁图谱构建与一种新的AFLPs共显性分析方法探讨

利用一个F2作图群体(X178×B73),首先构建了一个含有130个SSRs的玉米连锁框架图,然后用119个AFLPs位点增加图谱密度,得到一个全长1659·3cM,标记间平均间距6·66cM的玉米相对饱和连锁图。同时,对SSRs和AFLPs的一些遗传特性进行了分析,探讨了AFLP标记进行共显性分析的一种新方法。分析表明SSRs和AFLPs分子标记具有多态性和可靠性高等特点,是构建高密度分子标记遗传连锁图的有效技术。加密的玉米遗传连锁图谱为比较基因组研究、数量性状位点(quantitativetraitloci,QTLs)克隆、杂种优势机理研究以及标记辅助选择等提供了技术基础。     

中国植物遗传连锁图谱构建研究进展

遗传连锁图谱构建是基因组研究中的重要环节,是基因定位与克隆乃至基因组结构与功能研究的基础上。近十几年来,分子生物学特别是分子标记技术的飞速发展,为构建高饱和的植物遗传连锁图谱和利用分子标记进行辅助育种奠定了基础。综述了我国在植物遗传连锁图谱构建研究方面的进展及发展动态,列举了我国利用DNA分子标记构建的34张植物遗传连锁图谱实例,且讨论了当前我国在该领域研究中存在的问题并提出了解决途径。     

桃''秦光2号''×''曙光''F1代SSR遗传连锁图谱的构建

以桃品种‘秦光2号’和‘曙光’及其90株F1代群体为试验材料,依据SSR标记构建桃的遗传连锁图谱。构建的图谱覆盖桃基因组640cM,包含16个连锁群、73个标记,标记间平均图距为11.7cM;桃的白/黄肉性状(Y/y)、离/粘核性状(F/f)被分别定位在第8连锁群和第9连锁群上,距其相邻的分子标记距离分别为4和5cM。所构建的遗传连锁图谱可用于进一步研究。     

Genome conservation among three legume genera detected with DNA markers.

A set of 219 DNA clones derived from mungbean (Vigna radiata), cowpea (V. unguiculata), common bean (Phaseolus vulgaris), and soybean (Glycine max) were used to generate comparative linkage maps among mungbean, common bean, and soybean. The maps allowed an assessment of linkage conservation and collinearity among the three genomes. Mungbean and common bean, both of the subtribe Phaseolinae, exhibited a high degree of linkage conservation and preservation of marker order. Most linkage groups of mungbean consisted of only one or two linkage blocks from common bean (and vice versa). The situation was significantly different with soybean, a member of the subtribe Glycininae. Mungbean and common bean linkage groups were generally mosaics of short soybean linkage blocks, each only a few centimorgans in length. These results suggest that it would be fruitful to join maps of mungbean and common bean, while knowledge of conserved genomic blocks would be useful in increasing marker density in specific genomic regions for all three genera. These comparative maps may also contribute to enhanced understanding of legume evolution.     

Comparative genome analysis of mungbean (Vigna radiata L. Wilczek) and cowpea (V. unguiculata L. Walpers) using RFLP mapping data

Genome relationships between mungbean (Vigna tradiata) and cowpea (V. Unguiculata) based on the linkage arrangement of random genomic restriction fragment length polymorphism (RFLP) markers have been investigated. A common set of probes derived from cowpea, common bean (Phaseolus vulgaris), mungbean, and soybean (Glycine max) PstI genomic libraries were used to construct the genetic linkage maps. In both species, a single F₂ population from a cross between an improved cultivar and a putative wild progenitor species was used to follow the segregation of the RFLP markers. Approximately 90% of the probes hybridized to both mungbean and cowpea DNA, indicating a high degree of similarity in the nucleotide sequences among these species. A higher level of polymorphism was detected in the mungbean population (75.7%) than in the cowpea population (41.2%). Loci exhibiting duplications, null phenotypes, and distorted segregation ratios were detected in both populations. Random genomic DNA RFLP loci account for about 89% of the currently mapped markers with a few cDNA and RAPD markers added. The current mungbean map is comprised of 171 loci/loci clusters distributed in 14 linkage groups spanning a total of 1570cM. On the other hand, 97 markers covered 684 cM and defined 10 linkage groups in the current cowpea map. The mungbean and cowpea genomes were compared on the basis of the copy number and linkage arrangement of 53 markers mapped in common between the two species. Results indicate that nucleotide sequences are conserved, but variation in copy number were detected and several rearrangements in linkage orders appeared to have occurred since the divergence of the two species. Entire linkage groups were not conserved, but several large linkage blocks were maintained in both genomes.     

Comparative molecular mapping in Ceratotropis species using an interspecific cross between azuki bean (Vigna angularis) and rice bean (V. umbellata)

A genetic linkage map was developed with 86 F₂ plants derived from an interspecific cross between azuki bean (Vigna angularis, 2n=2x=22) and rice bean (V. umbellata, 2n=2x=22). In total, 14 linkage groups, each containing more than 4 markers, were constructed with one phenotypic, 114 RFLP and 74 RAPD markers. The total map size was 1702 cM, and the average distance between markers was 9.7 cM. The loci showing significant deviation from the expected ratio clustered in several linkage groups. Most of the skewed loci were due to the predominance of rice bean alleles. The azuki-rice bean linkage map was compared with other available maps of Vigna species in subgenus Ceratotropis. Based on the lineage of the common mapped markers, 7 and 16 conserved linkage blocks were found in the interspecific map of azuki bean ×V. nakashimae and mungbean map, respectively. Although the present map is not fully saturated, it may facilitate gene tagging, QTL mapping and further useful gene transfer for azuki bean breeding. Received: 20 March 1999 / Accepted: 29 April 1999     

A genetic linkage map of azuki bean constructed with molecular and morphological markers using an interspecific population (Vigna angularis x V. nakashimae)

A genetic linkage map of azuki bean (Vigna angularis) was constructed with molecular and morphological markers using an F₂ population of an interspecific cross between azuki bean and its wild relative, V. nakashimae. In total, 132 markers (108 RAPD, 19 RFLP and five morphological markers) were mapped in 14 linkage groups covering 1250 cM; ten remained unlinked. The clusters of markers showing distorted segregation were found in linkage groups 2, 8 and 12. By comparing the azuki linkage map with those of mungbean and cowpea, using 20 RFLP common markers, some sets of the markers were found to belong to the same linkage groups of the respective maps, indicating that these linkage blocks are conserved among the three Vigna species. This map provides a tool for markerassisted selection and for studies of genome organization in Vigna species.     

Construction of a Genetic Linkage Map and Genetic Analysis of Domestication Related Traits in Mungbean (Vigna radiata)

The genetic differences between mungbean and its presumed wild ancestor were analyzed for domestication related traits by QTL mapping. A genetic linkage map of mungbean was constructed using 430 SSR and EST-SSR markers from mungbean and its related species, and all these markers were mapped onto 11 linkage groups spanning a total of 727.6 cM. The present mungbean map is the first map where the number of linkage groups coincided with the haploid chromosome number of mungbean. In total 105 QTLs and genes for 38 domestication related traits were identified. Compared with the situation in other Vigna crops, many linkage groups have played an important role in the domestication of mungbean. In particular the QTLs with high contribution were distributed on seven out of 11 linkage groups. In addition, a large number of QTLs with small contribution were found. The accumulation of many mutations with large and/or small contribution has contributed to the differentiation between wild and cultivated mungbean. The useful QTLs for seed size, pod dehiscence and pod maturity that have not been found in other Asian Vigna species were identified in mungbean, and these QTLs may play the important role as new gene resources for other Asian Vigna species. The results provide the foundation that will be useful for improvement of mungbean and related legumes.     

Development of a mungbean ( Vigna radiata) RFLP linkage map and its comparison with lablab ( Lablab purpureus) reveals a high level of colinearity between the two genomes

A genetic linkage map of mungbean (Vigna radiata, 2n = 2x = 22) consisting of 255 RFLP loci was developed using a recombinant inbred population of 80 individuals. The population was derived from an inter-subspecific cross between the cultivated mungbean variety 'Berken' and a wild mungbean genotype 'ACC 41' (V. radiata subsp. sublobata). The total length of the map, which comprised 13 linkage groups, spanned 737.9 cM with an average distance between markers of 3.0 cM and a maximum distance between linked markers of 15.4 cM. The mungbean map was compared to a previously published map of lablab (Lablab purpureus, 2n = 2x = 24) using a common set of 65 RFLP probes. In contrast to some other comparative mapping studies among members of the Fabaceae, where a high level of chromosomal rearrangement has been observed, marker order between mungbean and lablab was found to be highly conserved. However, the two genomes have apparently accumulated a large number of duplications/deletions after they diverged.     

Genome dissection of traits related to domestication in azuki bean (Vigna angularis) and comparison with other warm-season legumes

BACKGROUND: The objective of this study was to dissect into quantitative trait loci (QTLs) the large morphological and physiological differences between cultivated azuki bean (Vigna angularis) and a wild relative and to infer the commonalities of the QTLs for domestication-related traits across the Asian Vigna and with other warm-season legumes. METHODS: Two linkage maps, for the BC(1)F(1) and F(2) populations, respectively, from the same cross between azuki bean and V. nepalensis were developed. Using these linkage maps QTLs for 33 domestication-related traits were analysed and mapped. The location of mapped QTLs was compared with locations of similar QTLs in other warm-season legumes. KEY RESULTS: QTLs were detected for seed-, pod-, stem- and leaf-related traits. Most traits were controlled by between two and nine QTLs but several traits, such as pod dehiscence, were controlled by single genes. QTLs for domestication-related traits were restricted to particular regions of the azuki bean genome, especially linkage groups 1, 2, 4, 7 and 9. Linkage groups 1 and 2 had QTLs for a suite of traits including pod size, germination, seed size and lower stem length. QTLs on linkage groups 7 and 9 were associated with upper stem length, maximum leaf size and pod and seed size. Pleiotropy or close linkage of genes for domestication-related traits is suggested in these regions. While some QTLs are common to azuki bean and other warm-season legumes, many are recorded for the first time in azuki bean. CONCLUSIONS: QTLs for a large number of domestication-related traits have been mapped for the first time in azuki bean. QTLs with unexpected effect and new QTLs for traits such as seed size have been found. The results provide a foundation that will be useful for improvement of azuki bean and related legumes.     

RFLP mapping of a major bruchid resistance gene in mungbean (Vigna radiata,L. Wilczek)

Summary Bruchids (genus Callosobruchus) are among the most destructive insect pests of mungbeans and other members of the genus, Vigna. Genetic resistance to bruchids was previously identified in a wild mungbean relative, TC1966. To analyze the underlying genetics, accelerate breeding, and provide a basis for map-based cloning of this gene, we have mapped the TC1966 bruchid resistance gene using restriction fragment length polymorphism (RFLP) markers. Fifty-eight F₂ progeny from a cross between TC1966 and a susceptible mungbean cultivar were analyzed with 153 RFLP markers. Resistance mapped to a single locus on linkage group VIII, approximately 3.6 centimorgans from the nearest RFLP marker. Because the genome of mungbean is relatively small (estimated to be between 470 and 560 million base pairs), this RFLP marker may be suitable as a starting point for chromosome walking. Based on RFLP analysis, an individual was also identified in the F₂ population that retained the bruchid resistance gene within a tightly linked double crossover. This individual will be valuable in developing resistant mungbean lines free of linkage drag.     

用于绿豆种质资源遗传多样性分析的SSR及STS引物的筛选

目前能够用于绿豆(Vigna radiate)种质资源遗传多样性分析的PCR引物极其有限。通过12份农艺性状差异较大的绿豆种质对绿豆以及小豆(Vigna angularis)、豇豆(Vigna unguiculata)、菜豆(Phaseolus vulgaris)等近缘食用豆中的PCR引物进行筛选,结果表明41对绿豆SSR引物中能够有效扩增的有35对,6对有多态性;28对绿豆STS引物中有23对能够有效扩增,2对有多态性;8对小豆SSR引物能够有效扩增的有6对,但均无多态性;27对豇豆SSR引物能够有效扩增的有17对,1对有多态性;24对菜豆SSR引物能够有效扩增的有9对,1对有多态性。这些多态性引物的获得将有助于中国绿豆种质资源的遗传多样性分析。