Wen Mingfu, Wang Haiyan, Xia Zhiqiang, Zou Meiling, Lu Cheng, Wang Wenquan
Institute of Tropical Biosciences & Biotechnology, Chinese Academy of Tropical Agricultural Science, 571101, Haikou, Hainan, PR China.
BMC Res Notes. 2010 Feb 24;3:42. doi: 10.1186/1756-0500-3-42.
Jatropha curcas L. has attracted a great deal of attention worldwide, regarding its potential as a new biodiesel crop. However, the understanding of this crop remains very limited and little genomic research has been done. We used simple sequence repeat (SSR) markers that could be transferred from Manihot esculenta (cassava) to analyze the genetic relationships among 45 accessions of J. curcas from our germplasm collection.
In total, 187 out of 419 expressed sequence tag (EST)-SSR and 54 out of 182 genomic (G)-SSR markers from cassava were polymorphic among the J. curcas accessions. The EST-SSR markers comprised 26.20% dinucleotide repeats, 57.75% trinucleotide repeats, 7.49% tetranucleotide repeats, and 8.56% pentanucleotide repeats, whereas the majority of the G-SSR markers were dinucleotide repeats (62.96%). The 187 EST-SSRs resided in genes that are involved mainly in biological and metabolic processes. Thirty-six EST-SSRs and 20 G-SSRs were chosen to analyze the genetic diversity among 45 J. curcas accessions. A total of 183 polymorphic alleles were detected. On the basis of the distribution of these polymorphic alleles, the 45 accessions were classified into six groups, in which the genotype showed a correlation with geographic origin. The estimated mean genetic diversity index was 0.5572, which suggests that our J. curcas germplasm collection has a high level of genetic diversity. This should facilitate subsequent studies on genetic mapping and molecular breeding.
We identified 241 novel EST-SSR and G-SSR markers in J. curcas, which should be useful for genetic mapping and quantitative trait loci analysis of important agronomic traits. By using these markers, we found that the intergroup gene diversity of J. curcas was greater than the intragroup diversity, and that the domestication of the species probably occurred partly in America and partly in Hainan, China.
麻疯树作为一种新型生物柴油作物，已在全球范围内引起广泛关注。然而，目前对该作物的了解仍然非常有限，基因组研究也很少。我们使用可从木薯转移的简单序列重复（SSR）标记，分析了我们种质库中45份麻疯树种质间的遗传关系。
木薯的419个表达序列标签（EST）-SSR标记中有187个，182个基因组（G）-SSR标记中有54个在麻疯树种质间具有多态性。EST-SSR标记中，二核苷酸重复占26.20%，三核苷酸重复占57.75%，四核苷酸重复占7.49%，五核苷酸重复占8.56%，而大多数G-SSR标记为二核苷酸重复（62.96%）。187个EST-SSR位于主要参与生物和代谢过程的基因中。选择36个EST-SSR和20个G-SSR分析45份麻疯树种质间的遗传多样性。共检测到183个多态性等位基因。根据这些多态性等位基因的分布，45份种质被分为六组，其中基因型与地理起源相关。估计的平均遗传多样性指数为0.5572，这表明我们的麻疯树种质库具有较高的遗传多样性。这将有助于后续的遗传图谱构建和分子育种研究。
我们在麻疯树中鉴定出241个新的EST-SSR和G-SSR标记，这些标记将有助于重要农艺性状的遗传图谱构建和数量性状位点分析。通过使用这些标记，我们发现麻疯树的组间基因多样性大于组内多样性，并且该物种的驯化可能部分发生在美国，部分发生在中国海南。
