Peng KeQin

Establishment of the cell suspension culture system of Camptotheca acuminata.

The young leaves and stems of Camptotheca acuminata were used as the materials to study the effects of basic media and the phytohormone combination on callus induction and subculture of the callus and screen out the best cultural formula for cell suspension culture system of Camptotheca acuminata.The results showed that most suitable medium for callus induction was SH with 2.0 mg/L NAA and 0.5 mg/L 6-BA,and the callus inducing rate was 92%.MS medium with 2.0 mg/L 6-BA and 0.5 mg/L NAA was found to be the best subculture medium formula,and the callus induced under these conditions and it was suitable for cell suspension culture.

Observation of chloroplast ultrastructure of zebra leaf in rice mutant B411.

采用透射电镜技术,对水稻突变体B411＂斑马叶＂出现过程中叶片的叶绿体超微结构进行了研究。结果表明,在叶片包于叶鞘内的心叶期,叶片绿区叶绿体呈纺锤形,类囊体片层纵向整齐排列;黄区叶绿体呈不规则椭圆形,类囊体片层排列不规则。在叶片抽出叶鞘1d的嫩叶期,叶片绿区叶绿体类囊体片层增多并垛叠形成基粒结构,它们沿长轴整齐排列;黄区叶绿体类囊体膜断裂,片断化。在成熟期,叶片绿区叶绿体类囊体片层变得丰富和形成许多基粒结构;叶片黄区叶绿体内部结构严重解体,整个叶绿体呈高电子密度的囊泡状结构。在复绿期,叶片黄区逐渐变成绿色,叶绿体结构恢复正常,类囊体膜系统重建,且有序地沿叶绿体长轴方向排列,在基质中形成淀粉粒,表明其光合能力恢复。