抗生素对高粱愈伤组织诱导和生长的影响

用羧苄青霉素等抗生素进行抑菌试验,以羧苄青霉素和头孢霉素的抑菌效果较好.头孢霉素对高梁愈伤组织的毒性表现出比羧苄青霉素大.浓度低于500 mg/L羧苄青霉素对高梁愈伤组织的生长起促进作用;而分化率随着羧苄青霉素浓度的提高而下降.在农杆菌介导高梁遗传转化时,选用羧苄青霉素是合适的,浓度以250 mg/L为宜.高梁愈伤组织对潮霉素的反应比卡那霉素更敏感,高梁不同基因型愈伤组织对卡那霉素和潮霉素的反应在褐化(死亡)率上表现不同.在以潮霉素作为抗性筛选标记时,选择压以50～75 mg/L为宜.

Effects of antibiotics on callus induction in sorghum and subsequent growth of callus

Growth inhibition of Agrobacterium by 3 different antibiotics was demonstrated. Carbenicillin and cefotaxime gave better results than ampicillin in inhibiting Agrobacterium growth. Cefotaxime was significantly more toxic than carbenicillin in induction of callus in sorghum. Carbenicillin of concentration below 500 mg/L in MS medium showed positive effects on sorghum callus growth. The regeneration rate of shoots from sorghum callus, however, was decreased with increase of carbenicillin level from 50 mg/L to 1000 mg/L in MS medium. The ideal concentration of carbenicillin was 250 mg/L when used in genetic transformation of sorghum mediated by Agrobacterium. Sorghum callus was more sensitive to hygromycin than to kanamycin. Considering the rate of browning (dying), the responses to kanamycin and hygromycin were different among different sorghum genotypes. With hygromycin as the selection marker, the optimal selecting pressure was 50-75 mg/L.