Establishment and Characterization of Embryogenic Suspension in Sweetpotato
- 生命科学－已发表论文 
徐薯 18叶片接种在附加 2mg/L 2 ,4 D的MS固体培养基上 ,形成了质地松散的胚性愈伤组织 ,胚性愈伤组织在附加 1mg/L 2 ,4 D的MS液体培养基中进行悬浮培养 ,建立了增殖迅速、分散度良好的具有较高体胚分化能力的细胞悬浮系 .小型细胞团 (直径小于 35 0 μm)以 2 %～ 4%的接种量转移到无激素MS液体培养基中 ,可分化出大量体胚 .在继代初期 ,悬浮系 pH值呈下降趋势 ,细胞处于旺盛分裂时期 ,导致悬浮系鲜质量、干质量、细胞紧实体积(PVC)的显著升值 ;4d以后 ,pH值逐渐回升 ,细胞分裂缓慢而体积增长迅速 ,导致鲜质量、PVC增加而干质量少有变化 ;6d以后 pH值继续回升而细胞分裂和生长受到明显抑制Embryogenic friable callus were obtained from young leaves of Xushu-18 on MS medium supplemented with 2 mg/L 2,4-D. Rapidly-growing and well-dispersed regenerative suspension cell line was established by subculturing this kind of callus in liquid MS medium contained 1 mg/L 2, 4-D. After suspension cells and clusters (about 350 μm in diameter) were transformed into MS medium without hormone at the inoculation of 2%～ 4%, a large number of somatic embryos which could developed into complete plantlets on solid basic MS medium were produced. Direct relationship between the growth of suspension cells and pH changes in medium was also discovered: While culture medium pH decreased from 5.80 to 4.66 within the first 4 days culture, exponential increase in dry weight, fresh weight and PVC occurred. Although fresh weight and PVC kept increasing when pH went up to 5.20 between 4 and 6 day following subculture, the dry weight changed little. After 6 day culture, suspension cells grew much slowly while pH increased continually.