中文摘要：

以尾巨桉优良无性系无菌苗茎段为外植体,通过对多种不同浓度生长调节剂组合的优化,进行胚状体诱导研究;并对胚性与非胚性愈伤组织进行形态解剖学观察、相关生理指标检测以及相关基因荧光定量PCR分析,以揭示尾巨桉胚性愈伤组织非胚性化发生的机理,为建立尾巨桉体细胞胚胎再生体系提供参考.结果表明：（1）胚性愈伤组织在MS＋0.1 mg/L NAA＋0.01 mg/L TDZ培养基中诱导得到胚状体,外植体经过0.5 mol/L蔗糖处理12 h有助于胚性愈伤组织产生胚状体,胚状体最高发生率为16.7％.（2）尾巨桉胚性与非胚性愈伤组织石蜡切片观察发现,两者的细胞形态特征存在明显的差异,胚性愈伤组织细胞体积小,排列紧密,表现出典型的胚性细胞特征,而非胚性细胞比较大,排列疏松,细胞呈不规则形状.（3）生理生化指标检测结果表明,非胚性愈伤组织中蛋白质含量、SOD、PPO及CAT活性均显著低于胚性愈伤组织,非胚性愈伤组织中木质素、可溶性糖含量以及PAL和POD活性要高于胚性愈伤组织,二者的反肉桂酸4单加氧酶基因、淀粉磷酸化酶基因、谷胱甘肽硫转移酶基因、葡萄糖1磷酸腺苷酸转移酶基因、葡萄糖六磷酸异构酶基因、分支酸合酶基因以及苯丙氨酸解氨酶基因表达差异也达到显著水平.

英文摘要：

In this study,the somatic embryogenesis induction and shoot regeneration were studied systematically in elite clone of Eucalyptus urophylla × E.grandis by comparing the variety of combinations of different growth regulators.Embryogenic callus and non embryonic callus of E.urophylla× E.grandis were used as explants to study the changes of different kinds of callus,and the mechanism of embryogenic callus of E.urophylla× E.grandis was revealed through analyzing histocytological changes,detecting physiological,biochemical indices and fluorescence quantitative PCR.This work laid the foundations for plant regeneration of E.urophylla×E.grandis through somatic embryogenesis.（1）Somatic embryogenesis was observed in callus in the presence of MS＋0.1 mg/L NAA＋0.01 mg/L TDZ.The best somatic embryogenesis rate（16.7％） was obtained when explants treated with 0.5 mol/L sucrose for 12 h.The embryogenic cells were consisted of small,tight arrangement and has the phenotype of embryogenic cell.Non embryogenic cells were large loosely arranged and usually irregular.（2）Histological analysis of incubated explants revealed that embryogenic cells exhibited common features characteristic.（3）Proteins and activities of antioxidant enzymes were evaluated in embryogenic and non embryogenic calli in E.urophylla × E.grandis.For embryogenic calli,PPO,CAT,SOD activities and protein content showed the significantly higher level than those of non embryogenic calli.For non embryogenic calli,lignin and soluble sugar contents,POD and PAL activities showed the significantly higher level than those of embryogenic calli.There was a significant difference of the levels of gene mRNA expression among trans cinnamate 4 monooxygenase,starch phosphorylase,glutathione S transferase,glucose-1-phosphate adenylyltransferase,glucose-6-phosphate isomerase,chorismate synthase,PAL.The difference between embryogenic callus and non embryonic callus of E.urophylla × E.grandis was revealed.