Large-scale advances in SSR markers with high-throughput sequencing in Euphorbia fischeriana Steud

BACKGROUND: Euphorbia fischeriana Steud is a very important medicinal herb and has significant medical value for healing cancer, edema and tuberculosis in China. The lack of molecular markers for Euphorbia fischeriana Steud is a dominant barrier to genetic research. For the purpose of developing many simple sequence repeat (SSR) molecular markers, we completed transcriptome analysis with the Illumina HiSeq 2000 platform. RESULTS: Approximately 9.1 million clean reads were acquired and then assembled into approximately 186.3 thousand nonredundant unigenes, 53,146 of which were SSR-containing unigenes. A total of 76,193 SSR loci were identified. Of these SSR loci, 28,491 were detected at the terminal position of ESTs, which made it difficult to design SSR primers for these SSR-containing sequences, and the residual SSRs were thus used to design primer pairs. Analyzing the results of these markers revealed that the mononucleotide motif A/T (44,067, 57.83% of all SSRs) was the most abundant, followed by the dinucleotide type AG/CT (9430, 12.38%). Using 100 randomly selected primer pairs, 77 primers were successfully amplified in Euphorbia fischeriana Steud, and 79 were successfully amplified in three other related species. The markers developed displayed relatively high quality and cross-species transferability. CONCLUSIONS: The large number of EST-SSRs exploited successfully in Euphorbia fischeriana Steud for the first time could provide genetic information for research on linkage maps, variety identification, genetic diversity analysis, and molecular marker-assisted breeding.

Statues and research strategy of molecular breeding in Artemisia annua / 中国中药杂志

Malaria is one of the three most deadly diseases in the world. Artemisinin is the first line and effective drug for treating malaria, and only can be extracted from Artemisia annua. Therefore, it is of great significance to cultivate new varieties of A. annua with high artemisinin content. Based on the germplasm bank and the whole genome, transcriptome and genetic map, the authors can explore high-quality genes, stress-resistant genes and genetic markers which have been used for rapid breeding of superior varieties of A. annua. So these methods of molecular breeding will become the main breeding direction of A. annua in the future. The breeding times of new varieties of A. annua can be shortened with molecular breeding technology. Based on the genetic background and the current situation of molecular breeding of A. annua, the strategy and technical route of molecular breeding were discussed and worked out in this paper, which provided a guidance and scientific reference for molecular breeding of A. annua in the future.