Cross-species transferability of G-arboreum-derived EST-SSRs in the diploid species of Gossypium
Cross-species transferability of G-arboreum-derived EST-SSRs in the diploid species of Gossypium
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DOI：
10.1007/s00122-006-0261-y
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发表时间：
2006-05-01
影响因子：
5.4
通讯作者：
Zhang, Tianzhen
中科院分区：
文献类型：
--
作者：
Guo, Wangzhen;Wang, Wei;Zhang, Tianzhen
具有共同棉属起源的二倍体物种在形态上高度多样，并已被分为八个基因组群，命名为A-G和K。本研究利用207对来自亚洲棉的EST-SSR引物，在23个棉种、7个基因组的25份二倍体材料中进行了遗传转移性研究。我们发现，124（60%）的207对引物在所有25个加入产生扩增产物。其余83（40%）引物对产生的扩增，只有一个子集的物种，范围从13至22个物种，这是一致的一些基因组和物种特异性扩增。这些EST-SSR在22个二倍体物种中的4，554个组合（207个SSR × 22个物种）中的跨物种扩增率为96.5%，表明在棉属物种之间具有较高的可转移性。此外，检测到的多态性水平高，平均每SSR标记的等位基因数为6.53。重复基序类型和跨种扩增之间没有相关性。DNA测序结果表明，高水平的多态性的发现主要是由于重复基序的数量的变化和高的可转移性可以归因于这些二倍体棉物种之间的侧翼区域的较高水平的保守性。利用EST-SSR标记对这些二倍体物种中的重要基因进行分子标记，可以提高遗传信息在不同物种间的传递效率，进一步促进其向栽培棉物种的渗入。
Diploid species with a common Gossypium origin are highly diverse in morphology and have been classified into eight genomic groups designated A-G and K. In this study, the transferability of 207 Gossypium arboreum-derived expressed sequence tag-simple sequence repeat (EST-SSR) primer pairs was examined among 25 different diploid accessions representing 7 genomes and 23 Gossypium species. We found that 124 of the 207 (60%) primer pairs produced amplification products in all 25 accessions. The remaining 83 (40%) primer pairs produced amplification in only a subset of species, ranging from 13 to 22 species, which is consistent with some genome- and species-specific amplification. The cross-species amplification of these EST-SSRs in 22 diploid species was 96.5% in 4,554 combinations (207 SSRsx22 species), indicative of a high transferability among the Gossypium species. Furthermore, a high level of polymorphism with an average number of 6.53 alleles per SSR marker was detected. No correlation was found between the repeat motif type and cross-species amplification. DNA sequencing showed that the high-level polymorphism findings was mainly due to changes in the number of repeat motifs and that the high transferability can be attributed to a higher-level conservation in the flanking regions among these diploid Gossypium species. The transferability among these different diploid species presented here can increase the efficiency of transferring genetic information across species and further enhance their introgression into cultivated cotton species by the molecular tagging of important genes existing in these diploid species using the EST-SSR markers.