Ferguson M E, Burow M D, Schulze S R, Bramel P J, Paterson A H, Kresovich S, Mitchell S
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), 502324, Patancheru, Andhra Pradesh, India.
Theor Appl Genet. 2004 Apr;108(6):1064-70. doi: 10.1007/s00122-003-1535-2. Epub 2003 Dec 11.
A major constraint to the application of biotechnology to the improvement of the allotetraploid peanut, or groundnut ( Arachis hypogaea L.), has been the paucity of polymorphism among germplasm lines using biochemical (seed proteins, isozymes) and DNA markers (RFLPs and RAPDs). Six sequence-tagged microsatellite (STMS) markers were previously available that revealed polymorphism in cultivated peanut. Here, we identify and characterize 110 STMS markers that reveal genetic variation in a diverse array of 24 peanut landraces. The simple-sequence repeats (SSRs) were identified with a probe of two 27648-clone genomic libraries: one constructed using PstI and the other using Sau3AI/ BamHI. The most frequent, repeat motifs identified were ATT and GA, which represented 29% and 28%, respectively, of all SSRs identified. These were followed by AT, CTT, and GT. Of the amplifiable primers, 81% of ATT and 70.8% of GA repeats were polymorphic in the cultivated peanut test array. The repeat motif AT showed the maximum number of alleles per locus (5.7). Motifs ATT, GT, and GA had a mean number of alleles per locus of 4.8, 3.8, and 3.6, respectively. The high mean number of alleles per polymorphic locus, combined with their relative frequency in the genome and amenability to probing, make ATT and GA the most useful and appropriate motifs to target to generate further SSR markers for peanut.
将生物技术应用于改良异源四倍体花生（Arachis hypogaea L.）的一个主要限制因素是，利用生化标记（种子蛋白、同工酶）和DNA标记（RFLP和RAPD）时，种质系间的多态性匮乏。此前已有6个序列标签微卫星（STMS）标记可揭示栽培花生中的多态性。在此，我们鉴定并表征了110个STMS标记，这些标记揭示了24个花生地方品种的多样群体中的遗传变异。利用两个27648个克隆的基因组文库的探针鉴定出简单序列重复（SSR）：一个用PstI构建，另一个用Sau3AI/BamHI构建。鉴定出的最常见重复基序是ATT和GA，分别占所有鉴定出的SSR的29%和28%。其次是AT、CTT和GT。在可扩增引物中，81%的ATT重复和70.8%的GA重复在栽培花生测试群体中具有多态性。重复基序AT在每个位点显示出最大等位基因数（5.7）。基序ATT、GT和GA在每个位点的平均等位基因数分别为4.8、3.8和3.6。每个多态性位点的高平均等位基因数，再加上它们在基因组中的相对频率以及易于探测的特性，使得ATT和GA成为生成更多花生SSR标记的最有用且合适的目标基序。
