药用植物DNA标记辅助育种(一):三七抗病品种选育研究

DNA marker-assisted selection of medicinal plants(Ⅰ).Breeding research of disease-resistant cultivars of Panax notoginseng

药用植物DNA标记辅助育种以DNA多态性为基础,依据分子杂交、聚合酶链式反应、高通量测序等技术,筛选与高产、优质、抗逆等表型关联的DNA片段作为标记,辅助新品种的选育。该研究采用DNA标记辅助育种结合系统选育的技术,选育首个三七抗病新品种"苗乡抗七1号"。结果表明,基于RAD-Seq技术检测出抗病品种包含12个特异SNP位点,经验证record_519688位点与三七抗根腐病相关,包含此位点的基因片段可作为抗病品种的遗传标记辅助三七系统选育;与常规栽培种相比,抗病品种种苗根腐病及锈腐病的发病率分别下降83.6%,71.8%;二年生及三年生三七根腐病的发病率分别下降43.6%,62.9%。此外,依据与抗病关联的SNP筛选三七潜在的抗病群体,该模式扩大目标群体并提高选育效率。药用植物DNA标记辅助育种将加快药用植物新品种选育及推广的进程,保障中药材产业健康发展。

DNA marker-assisted selection of medicinal plants is based on the DNA polymorphism, selects the DNA sequences relat- ed to the phenotypes such as high yields, superior quality, stress-resistance and so on according to the technologies of molecular hy- bridization, polymerase chain reaction and high-throughput sequencing, and assists the breeding of new cuhivars. This study bred the first disease-resistant cultivar of notoginseng ＂Miaoxiang Kangqi 1＂ using the technology of DNA marker-assisted selection of medicinal plants and systematic breeding. The disease-resistant cuhivar of notoginseng contained 12 special SNPs based on the analysis of Re- striction-site Associated DNA Sequencing （RAD-Seq）. Among the SNP （record_519688） was related to the root rot-resistant charac- teristics, which indicated this SNP could serve as genetic markers of disease-resistant cuhivars and assist the systematic breeding. Corn-pared to the conventional cultivated cuhivars, the incidence rate of root-rot and rust-rot in notoginseng seedlings decreased by 83.6% and 71.8% , respectively. The incidence rate of root-rot respectively declined by 43.6% and 62. 9% in notoginseng cultivation for 2 and 3 years compared with those of the conventional cultivated cultivars. Additionally, the potential disease-resistant groups were screened based on the relative SNP, and this model enlarged the target groups and advanced the breeding efficiency. DNA marker-as- sisted selection of medicinal plants accelerated the breeding and promotion of new cultivars, and guaranteed the healthy development of Chinese medicinal materials industry.