【作者】 吴汉兵；

【导师】 韦家川； 张慧英；

【作者基本信息】 广西大学 ， 作物遗传育种， 2004， 硕士

【摘要】 以5010、502、S₂、S₄、农大五个玉米自交系为材料，进行幼胚培养，通过愈伤组织的诱导、继代、分化和植株再生试验，对影响玉米幼胚愈伤组织诱导率和胚性率的因素进行了分析；优化了一套诱导、继代和植株再生的方案；从细胞学、生化指标、分化植株的苗期以及成熟期性状的角度对继代各代胚性愈伤组织的遗传变异进行了研究，并拍摄到了一些变异类型的图片；分析了2，4-D的效用及其作用机制，研究结果表明，2，4-D为诱导和继代必需，但同时又是变异的主要诱发因素，在玉米幼胚诱导培养期使用2.0mg／L，胚性愈伤组织继代期使用1.0mg／L，后期继代适当地逐代降低使用浓度，对减少变异的累积，维持无性系的遗传稳定有利；高频继代可促进愈伤组织胚性生长、降低继代过程中愈伤组织分化，同时高频继代亦是造成遗传不稳定的因素之一，随继代次数增加，分化率下降，再生植株的变异率增加，以20天为继代周期比较有效；探讨了胚性愈伤组织长期继代的遗传稳定性规律，初步确立了利用本试验材料建立高效转基因受体的方法，认为在3～5代，为无性系稳定的世代，可用作转基因的稳定受体；6～10代，胚性细胞系呈少量的变异，是相对稳定的代系，可作一般的转基因受体；11～20代，为大量变异、分离的高代代系，遗传背景复杂不稳定，不宜作转基因受体。更多还原

【Abstract】 Callus were induced from immature embryos of inbred line of maize 5010, 502, S2 , S4 , and Nongda ,effects of different factors on the rate of inducement of embryogenic callus (EC.) were analyzed by inducing , culturing, differentiating and plant regenerating, the variation of EC. was studied by cytology biochemical traits of young plants and mature plants in fields . some variations were recorded by photos .The effect and mechanism of 2,4-D was fully analyzed . it shows that the 2,4-D is necessary for inducement and culturing ,but it is also the main factor which results in variation.using 2.0mg/L in inducement ,1.0mg/L in culturing and later reducing the concentration of 2,4-D gradually is benefit for genetic stability ,high frequency culturing can promote the growth of callus and reduce the differentiation in culturing. at the same time ,it is one of the factors which leads to the unstable of genetic .with the frequency of culturing increasing ,the rate of differentiating reduces ,and the variation of plants increases,20 days frequency is adaptive .Rules of EC.’s genetic stability are firstly discussed ,and the way of establishing efficient transgenic recipients is found .using the materials in the experiment .it is stable in 3-5th generations ,they can be used as transgenic recipients ,the 6~10th ones also can be used but is inferior ,and it can’t be used in 11~20th generations because of its high frequency variation.更多还原