【作者】 周丽艳；

【导师】 刘桂茹； 杨学举； 高书国；

【作者基本信息】 河北农业大学 ， 作物遗传育种， 2002， 硕士

【摘要】 甘薯是以块根进行无性繁殖的作物，研究甘薯人工种子较其它作物具有更重要的意义。目前，大多数甘薯品种的体细胞胚发生频率低，制约了甘薯人工种子的发展。本研究以冀东地区两个主要甘薯品种“138”、“一窝红”为试材，对体细胞胚诱导、发生及植株再生进行了探讨。用带腋芽茎段作繁殖体进行人工种子初步研究。 1．愈伤组织的诱导 将两个品种的茎段分别接种于附加不同浓度蔗糖、琼脂、肌醇、不同pH值的MS培养基上。结果表明，蔗糖浓度25g/L，琼脂0.8％，肌醇0.1％，pH值5～6有利于愈伤组织生长。 将两个品种的叶片、叶柄、茎段分别接种于附加不同种类和浓度的植物生长调节剂的MS培养基上，发现愈伤组织的产量和质量有很大差别。用1mg/L 2,4-D与KT（6-BA）搭配诱导的愈伤组织质地松脆，颜色淡黄，但是2,4-D浓度过高如4mg/L不利于愈伤组织生长。而NAA代替2,4-D使用，所诱导的愈伤组织质地坚硬，颜色淡绿。不同基因型之间也有差别，2,4-D浓度较低时，“一窝红”长势比“138”好。在三种外植体中，叶片形成的愈伤组织最多。 2．胚性与非胚性愈伤组织 诱导的愈伤组织有三种类型：第一种是NE型，颜色灰白，结构疏松，生长旺盛。其组成细胞为长条形等不规则形状，富含液泡。第二种为E型（胚性愈伤组织），颜色淡黄，质地松脆，表面有凸起，生长缓慢。第三种是G型，表面光滑，质地坚硬。E型和NE型愈伤组织可以转化。继代培养有利十提高胚性愈伤组织比率。 3．器官分化 将不同外植体的愈伤组织在不同培养基上进行器官分化。根的分化较容易，最高分化率达100％。芽的分化，最高分化率为33.3％。茎段和叶片比叶柄容易分化出芽。 4．液体培养 培养60天的“一窝红”胚性愈伤组织切碎在附加0，0.5，1，2，4mg/L 2,4-D的液体MS培养基中悬浮培养。不加2,4-D有利于体细胞胚发生。0.5-1.mg/L有利于悬浮系保持。 5．利用带芽茎段作繁殖体进行人工种子研究 将带不同长度腋芽的茎段用4％和6％的海藻酸钠包裹，用2％Cacl₂为固化剂，制成人工种子。在不同萌发基质上萌发。腋芽长度在一定范围内与萌发率呈正相关。海藻酸钠的最佳浓度是4％。萌发基质中加入MS和多菌灵有利于萌发。最高萌发率为62.5％。更多还原

【Abstract】 Sweet potato is the crop that reproduce generation through it’s root, so the study of artificial seeds of sweet potato is more important than the other crops’. Now the frequency of somatic embryogenesis of the most sweet potato species is low. Which restrict the development of sweet potato artificial seeds. The test has studied the somatic embryo induction and plant regeneration of "138" and "yiwohong".l.The induction and growth of callus Culture stems of the tow species on MS media added sucrose , agar, pH value in different consistency. The result show that media containing 25g/L sucrose, 0.8% agar, pH5~6 is good for callus to grow. Culture leaves, stems, petiols of "138" and "yiwohong" on MS media supplemented different plant growth regulator. Calli’ productions and qualities are very different. Calli induced from three types of explants on MS media added Img/L 2,4-D and KT are light yellow, crisp. But 2,4-d in high consistency is not good for callus growth. Added NAA instead of 2,4-D, the callus is hard and light green, "yiwohong" is better than "138" in growth vigor. Among the three sorts of explants, the leaf is the easiest to be induced.2. Embryogenic callus and nonembryogenic callus Calli induced from different explants are divided into three types(type NE,E and G). NE callus is pale, soft and lose. It grows quickly. The shape of it’s cells are irregular. Type E callus is slight yellow and crisp. It grows relatively slow. It’s cell is small and round, and containing reach cell matri. Type G callus is smooth and hard. Img/L 2,4-D is good for induction of type E callus. Continue culture can rise the rate of type callus.3.Organ differentiation Culture calli induced from different explants to differentiate organ. Root differentiation is easier than bud’s. It’s differentiation rate can arrive to 100%. Bud’s highest differentiation rate is 33.3%. Among the three sorts of explants, stem and leaf are easier than petiol in differentiation.4.Cell suspension culture Having cultured the embryogenic callus of "yiwohong" in liquid MS with 0,0.5,l,2,4mg/L 2,4-D, It show that the liquid media with no 2,4-D is good for somatic embryogenesis.5.Studies on artificial seeds of sweet potato Stems with auxiliary buds in different length are encapsulated with 4-6% sodium alginate and 2% calcium chloride to make artificial seeds. Artificial seeds are put into different germination matter to test it’s ability of germination. The germination rate is positive correlate with the length of auxiliary bud. The desirable consistency of sodium alginate is 4%. Addition of MS and 0.1% carbendazin can rise the germination rate of artificial seeds.更多还原