Moretzsohn M C, Leoi L, Proite K, Guimarães P M, Leal-Bertioli S C M, Gimenes M A, Martins W S, Valls J F M, Grattapaglia D, Bertioli D J
Embrapa Recursos Genéticos e Biotecnologia, C.P. 02372, CEP 70.770-900 Brasília, DF, Brazil.
Theor Appl Genet. 2005 Oct;111(6):1060-71. doi: 10.1007/s00122-005-0028-x. Epub 2005 Oct 11.
Cultivated peanut (Arachis hypogaea) is an important crop, widely grown in tropical and subtropical regions of the world. It is highly susceptible to several biotic and abiotic stresses to which wild species are resistant. As a first step towards the introgression of these resistance genes into cultivated peanut, a linkage map based on microsatellite markers was constructed, using an F(2) population obtained from a cross between two diploid wild species with AA genome (A. duranensis and A. stenosperma). A total of 271 new microsatellite markers were developed in the present study from SSR-enriched genomic libraries, expressed sequence tags (ESTs), and by "data-mining" sequences available in GenBank. Of these, 66 were polymorphic for cultivated peanut. The 271 new markers plus another 162 published for peanut were screened against both progenitors and 204 of these (47.1%) were polymorphic, with 170 codominant and 34 dominant markers. The 80 codominant markers segregating 1:2:1 (P<0.05) were initially used to establish the linkage groups. Distorted and dominant markers were subsequently included in the map. The resulting linkage map consists of 11 linkage groups covering 1,230.89 cM of total map distance, with an average distance of 7.24 cM between markers. This is the first microsatellite-based map published for Arachis, and the first map based on sequences that are all currently publicly available. Because most markers used were derived from ESTs and genomic libraries made using methylation-sensitive restriction enzymes, about one-third of the mapped markers are genic. Linkage group ordering is being validated in other mapping populations, with the aim of constructing a transferable reference map for Arachis.
栽培花生（Arachis hypogaea）是一种重要作物，广泛种植于世界热带和亚热带地区。它对多种生物和非生物胁迫高度敏感，而野生种对这些胁迫具有抗性。作为将这些抗性基因导入栽培花生的第一步，利用从两个具有AA基因组的二倍体野生种（A. duranensis和A. stenosperma）杂交获得的F(2)群体，构建了基于微卫星标记的连锁图谱。在本研究中，从富含SSR的基因组文库、表达序列标签（EST）以及通过“数据挖掘”GenBank中可用序列共开发了271个新的微卫星标记。其中，66个对栽培花生具有多态性。用这271个新标记加上另外162个已发表的花生标记对两个亲本进行筛选，其中204个（47.1%）具有多态性，包括170个共显性标记和34个显性标记。最初使用80个分离比例为1:2:1（P<0.05）的共显性标记来建立连锁群。随后将偏分离和显性标记纳入图谱。所得连锁图谱由11个连锁群组成，覆盖总图距1230.89 cM，标记间平均距离为7.24 cM。这是首次发表的基于微卫星的花生图谱，也是第一个基于目前均可公开获取序列的图谱。由于使用的大多数标记来自EST以及用甲基化敏感限制酶构建的基因组文库，约三分之一的定位标记是基因标记。正在其他作图群体中验证连锁群排序，目的是构建一个可转移的花生参考图谱。
