【作者】 王延秀；

【导师】 张福泉；

【作者基本信息】 甘肃农业大学 ， 果树学， 2002， 硕士

【摘要】 核桃（Juglans regia L．）别名胡桃、羌桃，属核桃科（Juglandacea）核桃属（Juglans）植物，是一种优良的干果树种，具有极高的经济价值。本试验以甘肃山核桃（Juglans regia L．）、美国黑核桃（duglans negro L．）、绵核桃、薄皮核桃、露仁核桃为试材，对外植体褐化的影响因子、初代培养、继代培养各个方面进行了研究，并对生根培养进行了初步的探讨。 核桃外植体的褐化受多种因子的影响：取材时间明显影响外植体的褐化率，在生长季中8月份褐化率最低，7月份褐化率最高；基因型也明显影响褐化率，黑核桃的褐化率在生长季极显著的高于山核桃，露仁核桃的褐化率也明显高于绵核桃；取材树的树龄越小，褐化率越低；随消毒时间的增长，褐化率升高，0.1％的HgCl₂溶液消毒8分钟时褐化率、污染率均较低，8分钟以上则加重褐化；褐化率与PPO活性的相关性不显著；褐化率与酚类物质含量呈极显著的正相关（R=0.791**）；Vc能明显的降低褐化率并减轻褐化发生的程度。无菌外植体建立时，山核桃在5月中旬新梢速长前期、黑核桃在8月中旬新梢二次速长期分别采集当年生新梢，用流水冲洗后先依次在70％酒精中浸泡10秒钟、0.1％HgCl₂中浸泡8分钟，两种核桃分别取得了51.62％和42.68％的成活率。绵核桃、薄皮核桃、露仁核桃实生苗使用0.1％HgCl₂分别消毒6分钟、4.5分钟、4.5分钟，取得了85％、67％、40％的成活率。 将无菌保存的材料接种在DKW+1.0mg／L BA+0.01mg／L IBA培养基上相比于相同激素配比的H培养基，芽萌动早，而且长的快，褐化率低。但不同品种之间的萌动开始期和生长势有明显的差异。绵核桃、山核桃萌动早、生长快，露仁核桃萌动最迟、长势差，黑核桃和薄皮核桃介于两者之间。 继代培养选用DKW培养基，增殖效果好于MS和H培养基；BA在嫩茎的增殖中不可缺少，其浓度在0.5-1.0mg／L时增殖效果较好；低浓度的IBA对BA的增殖有促进作用。在DKW培养基上附加BA1.0mg／L、IBA0.01mg／L取得了最高的增殖倍数。接种材料的大小明显影响褐化率和增殖倍数，以1.8cm左右最为适宜。增殖培养时，前期采用较低温度（22℃），中期（25-26℃）、后期（28 C）采用较高温度，能明显的促进生长，使增殖倍数上升到4．6。继代周期35 d，适当延长后期的高温阶段，可以显著的增加增殖倍数达到4．8。 用 D邯附加 BAO．25mg／L、IBAO．03。g／L进行壮苗培养，取得了生长整齐健 壮的试管苗。更多还原

【Abstract】 The micropropagation procedures of walnut (Juglans regia L.) and black walnut (Juglans negro L.) had been researched, including the factors affecting explants browning, the establishment of aseptic cultures, shoot proliferation, selection of suitable medium and hormone. A feasible and practical micropropagation system had been made.Factors affecting walnut browning are as follows: the time collect shoot affecting browning, in august, two species walnut both have the lowest browning rate; species also affecting browning, black walnut has a higher browning rate than walnut in the growth season; the older the age, the higher the browning rate; explants in 0.1%HgC12 less than 8 mins has a lower rate; PPO and browning rate’s correlation is not significant; but phenol concentration and browning rate has a very significant correlation, (R=0.791**); add Vc in the medium can greatly reduce the mortality due to browning. High survival rate of the explants can be achieved when the explants of walnut were collected in May and explants of black walnut were collected in August. Washing the explants under running water and in 0. !%HgC12 for 8 min, rinsed 3-4time with sterile water, the survival rate was 51.62% and 42.86%. Walnut of mianhetao seedling in 0.1%HgC12 for 6min, baopihetao and lourenhetao seedling in 0.1%HgC12 for 4.5min. The survival rate was 85%and 66.7%and 40% respectly.Culture the survival stem on DKW medium with l.Omg/LBA and O.Olmg/LIBA can quickly made the bud germinate and growth well.During the shoot proliferation, DKW medium was more suitable for growth and subculture of the shoots than on MS and H medium. The exogenous application of cytokinins-BA was very necessary for shoot proliferation, 0.5-l.Omg/LBA have a higher proliferation rate, combination of cytokinin and lower concentration auxin-IB A can stimulate the growth of shoots. Thus the optimal proliferation medium was DKW medium supplement with l.Omg/LBA, O.Olmg/LIBA. It was good to keep the cultures at 22癈,16hr. photoperiod in the first 7 days, then at 25-26癈 in the middle phase, at 28 癈 in the last 7days, the proliferation rate can reached 4.6.Enlonger the last period to 12d,subcultures every 35d, have a proliferation rate 4.8.DKW medium added BA0.25mg/L, IBA0.03mg/L made the shoot elongation and better growth.更多还原