羊草(Leymus chinensis)为异源四倍体禾本科牧草, 利用成熟胚诱导愈伤组织获得再生植株的效率极低, 难以运用遗传转化方法进行品种改良。我们以羊草成熟胚为外植体, 使用适宜羊草愈伤组织生长的新型培养基配方, 筛选诱导愈伤组织、不定芽分化及生根阶段的最适植物激素浓度、光照和温度条件, 从而优化羊草成熟胚的组织培养方案。研究结果表明, 羊草成熟胚诱导阶段2,4-D的最适浓度为2.0 mg·L ^-1, 变温暗培养, 诱导率可达74.1%; 分化阶段6-BA和NAA的最适浓度均为1.0 mg·L ^-1, 分化率可达57.1%; 生根阶段NAA的最适浓度为0.25 mg·L ^-1, 移栽后成活率为100%。

Leymus chinensis is a heterotetraploid grass. It is hard to use genetic transformation method for improving breeding since the efficiency of regeneration using callus induced from mature embryo is very low. In this study, we optimized the protocol of culturing mature embryo with L. chinensis as explants by screening optimum plant hormone concentrations, light conditions and culturing temperatures at different culturing stages including callus induction, differentiation, rooting and transplanting. Our results showed at the callus induction stage, the induction rate could reach up to 74.1% under 2.0 mg·L ^-12,4-D, variable temperature and dark culture. The differentiation rate could reach up to 57.1% with optimum condition of 1.0 mg·L ^-16-BA and 1.0 mg·L ^-1NAA. In the rooting stage, the survival rate was 100% when cultured with 0.25 mg·L ^-1NAA.