玉米自交系愈伤组织的诱导、RAPD分析及扫描电镜观察

Observation with Scanning Electron Microscope and Analysis of RAPD on Tissue Culture and Embryogenesis of Inbreds of Zea mays L.

以玉米不同自交系的幼胚为材料 ,用诱导培养基进行培养 ,以获得愈伤组织。结果发现所有自交系幼胚均可诱导出白色或黄白色的愈伤组织 ,但其再生能力差异显著 ,这主要取决于基因型和培养基种类。自交系 792 2、 340幼胚的再生频率高达 85 .5 %和 78%。植株再生途径也有所不同 ,890 2、 Mo17、 4 112和 84 6以器官发生途径为主 ,340、 792 2、92 1、 85 3和 835以体胚发生途径为主。经长期继代的愈伤组织失去再生能力。通过 RAPD方法发现不同愈伤组织的基因组之间存在差异。通过扫描电镜观察发现玉米体胚发生有两种情况 :一是直接诱导产生胚性愈伤组织和胚状体 ;

Immature embryos of different maize inbreds were cultured in induced medium. All types formed pale yellow to yellow callus on the medium. Results indicated that plant regeneration was chiefly controlled by genotypes and kinds of medium. The rate of regeneration for inbreds 7922 and 340 was 85.5% and 78% respectively. There are different ways in the regeneration, and 8902, Mo17, 4112 and 846 tended to regenerate via organogensis, while 340, 7922, 921, 853 and 835 were likely to regeneration via somatic embryogenesis. Some calli lost their capacity of embryogenesis during long time subculture. The results of randomly amplified polymorphic DNA (RAPD) showed that the genomic DNA was modified in tissue culture. Two patterns of maize somatic embryogenesis were found by observation with scanning electron microscope. One was induced directly from immature embryo, and the other produced embryoids after subculturing several times.