【作者】 李俊红；

【导师】 李周岐；

【作者基本信息】 西北农林科技大学 ， 林木遗传育种， 2008， 硕士

【摘要】 杜仲(Eucommia ulmoides Oliv.)属于杜仲科杜仲属,是一种以药用为主并具有多种用途树种,具有很高的开发利用价值。和其它所有栽培植物一样,良种选育是杜仲资源开发中一项极其重要的基础性工作。鉴于多倍体植物具有器官巨大、抗逆性强和生化物质含量高等特点,及杜仲的利用途径和价值,多倍体育种应成为杜仲遗传改良的主要途径之一。秋水仙素是人工诱导多倍体的主要化学物质,用于处理的植物材料和处理方法很多,其中以成熟种子为材料进行染色体加倍是最为常用的方法。近年来,随着植物组织培养技术的发展和完善,利用离体组织染色体加倍法进行多倍体诱导已在许多植物中取得成果。而要利用组织培养对离体组织进行染色体加倍,首先要建立高效的组织培养再生体系。因此,本文在前人研究工作基础上,对杜仲组织培养再生体系进行了优化,并以成熟种子为材料进行多倍体诱导与鉴定技术的研究。其主要研究结果如下:1.杜仲离体快繁体系的优化:以幼嫩叶片为外植体,对杜仲再生体系的优化进行了研究。结果表明:叶片诱导愈伤组织的最适培养基为MS + NAA1.5 mg/L + 6-BA2.0 mg/L,诱导率为95%、愈伤组织增殖最适培养基为MS+NAA1.0 mg/L +6-BA2.0 mg/L,良好率为98.5%、诱导不定芽的最适培养基为MS+ NAA0.5 mg/L +6-BA2.0mg/L,分化率为40%、最适生根培养基1/2MS+IBA1.5 mg/L,生根率为92.5%。2.杜仲多倍体的诱导鉴定:0.2%的秋水仙素水溶液浸泡处理种子48h诱导的多倍体最多,诱导率高达13%。种子用秋水仙素处理后再进行试管萌发处理,其多倍体的诱导率高于培养基中添加秋水仙素直接进行试管萌发的处理。试验共获得杜仲多倍体植株43株。对杜仲二倍体和多倍体的气孔进行了观察比较发现二倍体杜仲的气孔长度小于多倍体的,气孔密度则相反。进一步与染色体计数法直接鉴定相比,其误差不超过25%,气孔大小及密度也可以作为鉴定多倍体的可靠间接指标。更多还原

【Abstract】 Eucommia ulmoides oliv. is a multipurpose tree species,which belongs to Eucommia,Eucommia oliv..It is worth exploring. The same as other cultivated tree species, the breeding of Eucommia ulmoides oliv. is an extremely important basic work in the exploitation of resource. Polyploid plants have many advantages such as gigantic organs and strong stress resistance,so polyploid breeding is one of important ways of breeding.Colchicine is one of chemical substances which are used to polyploid inducement. There are many treatment materials and methods ,but the method of chromosome doubling using mature seeds as material has been applied widely. In the recent years,with the developing of plant tissue culture techunique,artificial chromosome doubling in vitro is an efficient approach to produce polyploidy plants.If artificial chromosome doubling in vitro is used, a high-efficient tissue culture system must be established. In the study,based on previous research results, regeneration system was optimized, and using mature seeds as material the technologies of polyploid inducement and identification was studied . The main results are as follows:1. In vitro propagation system was optimized: Optimization of regeneration system was studied by using tender leaves as explant. The results showed that : MS+NAA1.5 mg/L +6-BA2.0 mg/L had the best effects on induced to callus,and the rate of callus formation was 95%; the best medium of callus growth is MS+NAA1.0 mg/L +6-BA2.0 mg/L ,and good result archived in 98.5% ; the suitable medium for bud formation is MS medium added NAA0.5 mg/L, 6-BA2.0mg/L,and buds differentiation rate was 40%;the optimum media for rooting is 1/2MS+IBA1.5mg/L with 92.5% rooting ratio.2. Polyploidys induction: the best method for polyploids induction is soaking seeds in 0.2% liquid colchicum for about 48h. The highest induction ratio is about 13%. Seeds soaked with colchicum and then cultured in medium would have a higher polyploids induction ratio than cultured directly in medium with colchicum. Total 43 polyploids individuals were obtained in this study.By observing plant stomata, it shows us the stomas are larger than diploid, but the tetraploid density is smaller. The pore size and density could be used as a reliable indirect index in Eucommia ulmoides Oliv. polyploids appraisal.更多还原