【作者】 张婕；

【导师】 高亦珂；

【作者基本信息】 北京林业大学 ， 园林植物与观赏园艺， 2012， 硕士

【摘要】 地被菊是重要的园林地被植物。地被菊具高度杂合,遗传背景复杂,因而难以通过传统方法得到纯合自交系。通过花药或未授粉胚珠培养诱导单倍体则可在加倍后获得纯系,提高育种效率。已有研究通过地被菊花药培养获得单倍体植株,但地被菊未授粉胚珠培养未见相关研究报道。本研究希望通过地被菊未授粉胚珠培养获得单倍体植株,并探讨离体雌核发育机理。实验研究了影响地被菊胚珠培养的各种因素,并获得单倍体。对不同倍性再生植株气孔及形态特征进行统计分析,对离体雌核发育过程进行切片观察。主要研究成果如下：1.地被菊花序形态和胚囊发育时期具有相关性。胚囊发育成熟,舌状花完全展开,管状花即将开放时胚珠诱导效果最佳。2.不同基因型地被菊诱导培养基不同。基因型WS最适培养基为MS+6-BA2.0mg/L+NAA0.5mg/L+蔗糖30g/L或MS+6一BA2.0mg/L+NAAO.5mg/L+蔗糖60g/L。基因型PD为MS+6-BA1.0mg/L+NAA0.5mg/L+蔗糖30g/L。分化培养基为MS+6-BA2.0mg/L+NAA0.05mg/L+30g/L蔗糖。3.光照条件下胚珠愈伤组织诱导率显著高于黑暗条件。WS光照条件下诱导率为68.9%,黑暗条件下仅为4.4%。4.低温预处理对胚珠培养有一定促进作用。4℃预处理3天胚珠诱导率最高,为76.25%。5.实验共获再生植株75株,对20株WS再生植株检测获得单倍体(n=3x=27)、四倍体(2n=4x=36)、非整倍体(2n=5x-3=42)、五倍体(2n=5x=45)各一株,并进行染色体核型分析。6.地被菊胚珠培养3天时极核和反足细胞开始启动分裂。胚囊合点端和珠孔端均能形成胚状体,合点端胚状体推测为反足细胞起源,珠孔端胚状体可能由卵细胞或助细胞发育而来。更多还原

【Abstract】 Ground-cover chrysanthemum is an important landscape ground cover plant. Because of self-incompatibility, it is difficult to obtain homozygous inbred lines. Pure lines can be quickly obtained by anther or unpollinated ovule culture. It has been reported that haploids can be obtained by anther culture of ground-cover chrysanthemum, in which ovule culture has not been reported. The aim of this study is to develop an ovule culture system to produce haploid of ground-cover chrysanthemum, and understand the mechanist of gynogenesis. The effect of various treatment for ovule culture was investigated. Stomata character and plant morphology of different ploidy have been compared. The embryology and the procedure of the induction of gynogenesis were studied. The main results were as follows:1. Chrysanthemum inflorescence morphology had correlation with embryo sac development period. When the ray florets fully unfolded and vertical to receptacle, the embryo sac is mature. Ovules collected when ray florets was fully opened and disk flower was about to open induced the highest frequency of callus induction.2. Different genotypes of ground-cover chrysanthemum induced in different mediums. WS was benefit to cultured in the medium:MS+6-BA2.0mg/L+NAA0.5mg/L+sucrose30g/L or MS+6-BA2.0mg/L+NAA0.5mg/L+sucrose60g/L. PD was benefit to cultured in the medium: MS+6-BA1.Omg/L+NAA0.5mg/L+sucrose30g/L. Differentiation medium was MS+6-BA2.0mg/L+NAA0.05mg/L+30g/L sucrose.3. Ovule callus induction rate under light condition was significantly higher than under the dark conditions.4. The low temperature pretreatment can improve callus induction to some extent. Cullus induction rate as high as76.25%was achieved after3days cold pretreatment at4℃.5.75regenerated plants were obtained in the study. The ploidy of20plants regenerated from WS were checked and obtained one haploid (n=3x=27), one tetraploid(2n=4x=36), one pentaploid (2n=5x=45) and an aneuploid(2n=5x-3=42).6. It was observed that antipodal cells were able to start division after3days culture, and then developed as the form of callus. The embryoid was also observed at micropylar end..更多还原