N6培养基添加钙和烯效唑对玉米幼胚培养的作用

通过浓度筛选和比较试验，将以N6培养基为基础的诱导培养基和继代培养基的钙浓度，从1.13 mmol/L提高到5 mmol/L，并分别添加1.00 mg/L和0.50 mg/L 烯效唑（S-3307），对玉米幼胚胚性愈伤组织的诱导和继代具有促进作用，而不影响胚性愈伤组织的分化再生。在分化培养基中添加低浓度（0.25 mg/L）S-3307，能显著提高分化再生率

Effect of Ca2+ and Uniconazole Appended in N6 Medium on Immature Embryos Culture in Maize

The establishment of transgenic acceptor sy stem with stable genetic characters, effective transgenic ratio and easy plant regeneration is one of the key techniques in transgenic operation. Up to now, the most effective measure to establish transgenic acceptor system in maize is t he inducement and culture of embryonic callus from immature embryos. Inducement , subculture, differentiation and regeneration of embryonic callus in maize ar e much more difficult than in other graminaceous crops such as rice, and heavily depend on several model inbred lines of tissue culture such as A188, B73 and th eir derivatives. The comprehensive agronomic characters of these lines do not m eet production requirement and transgenic plants from these lines can be applied to commercial hybrid combination only through a long time of complex backcross breeding program. Elite parent inbred lines of disseminated hybrids, however, are much more difficult to induce embryonic callus and provide enough acceptor for transgenic operation. Ca 2 was found to promote callus growth, but this promotion effect was reduced chlorpromazine (CPZ), that combined with calcium regulation proteins (C aM) and blocked information transmission of Ca 2 /CaM system. Uniconazole with low concentration was reported to have significant improvement on callus in ducement and plant regeneration. Multi-effect trizole was found to have inhibi tory effect on callus inducement from immature embryo. Through concentration screening and comparative experiment, Ca 2 concen tration of inducement and subculture media based on N6 medium was increased from 1.13 to 5 mmol/L. Uniconazole (S-3307) of 1.00 and 0.50 mg/L was separatel y added to inducement and subculture media. The two improvements of medium comp onents showed a promotion effect on inducement and subculture growth of embryoni c callus from immature embryos in maize, without harmful influence to different iation and regeneration of embryonic calli. Addition of S-3307 with low concen tration (0.25 mg/L) to differentiation medium was showed to have significant pr omotion effect on differentiation and growth of regenerated plants. However, t he inducement of embryonic calli from the inbred lines with low callus inducemen t rate, such as R15, was not improved by the addition of Ca 2 and S-330 7. The promotion effect of calcium increased could be inhibited by chlorpromazi ne (CPZ), CaM inhibitor, that was added to the medium with 5 mmol/L Ca 2 . This result indicted that the promotion effect of calcium increased on induce ment and subculture growth of embryonic calli was related with information regul ation of Ca 2 /CaM system. These improvements to N6 medium were suggested to be used to increase inducement rate and subculture growth of embryonic calli from elite maize inbred lines and provide acceptor system with elite genetic fou ndation for transgenic research.