紫花苜蓿高频体细胞胚与次生胚再生体系的建立

通过系统地对紫花苜蓿体细胞胚发生以及次生胚发生途径中若干影响因子的比较研究,建立了紫花苜蓿高频体细胞胚和次生胚再生体系.结果表明,体细胞胚再生体系及次生胚再生体系均具有严格的基因型依赖性,不同的品种间以及同一品种内的不同株系间再生频率存在较大差别;MSO培养基可作为胚状体成苗培养基,但次生胚在MSO培养基中成苗率较低而再次形成新的胚状体;改良无激素SH培养基可有效终止次生胚的发生,并诱导次生胚成苗.此外,从6个紫花苜蓿品种中筛选到3个具有较强胚状体再生能力的品种,6个高胚状体发生能力的株系,2个具有较强的次生胚发生能力的株系,为进一步的遗传转化奠定了基础.

Establishment of High Frequency Regeneration System Via Somatic Embryogenesis and Secondary Embryogenesis for Alfalfa

Systematic investigations were performed of impact factors influencing the plant regeneration of Medicago sativa, in order to establish a regeneration system with high efficiency for genetic improvement. Results show that the efficiency of regeneration by bothprotocols is dependent stringently on the genotype of the explants. Vast differences in the regeneration rate were found among not only different cultivars but also individuals within a cultivar. MSO medium can be used as a medium for plantlet formation of the somatic embryo. However, secondary embryos on the MSO medium developed into plantlets with a very low rate, but formed new embryoids. The modified phytohormone-free SH medium was selected to terminate the formation of secondary embryoids and induce plantlet formation. From the 6 cultivars investigated 3 were found to possess high potential to regenerate via somatic embryogenesis, and 6 and 2 lines with high plant regeneration ability were selected, respectively, for somatic embryogenesis and secondary embryogenesis, which lays the foundation for genetic transformation.