【摘要】 以15 a生银杏(Ginkgo bilobaL.)品种‘佛指’(G.bilobacv.‘Fozhi’)为材料,观察了授粉后胚珠结构、雌配子体发育和种皮分化形成的过程。结果表明:(1)授粉后2 d胚珠已分化出珠心、珠被和珠托组织,珠被顶端形成直径为162.16μm的珠孔与540.54μm长的珠孔道,珠心组织顶端形成长约520.83μm、最大直径约125.06μm的瓶状贮粉室,花粉粒经珠孔道已到达贮粉室并在其中停留;(2)雌配子体的发育先后经历了游离核阶段(授粉后5~30 d)和细胞化阶段(授粉后30~45 d),之后在近珠孔端形成颈卵器,其余部分发育为胚乳薄壁细胞,其营养物质的积累高峰期为授粉后60~80 d;(3)种皮分化与形成分别经历珠被分化期(授粉期至授粉后30 d)、种皮分化期(授粉后30~50 d)、种皮形成初期(授粉后50~80 d)、种皮形成期(授粉后80~90 d)。更多还原

【Abstract】 The 15 years-old trees from Ginkgo biloba L.cultivar ’Fozhi’ were selected to perform the observation on structure of ovule,process of development of female gametophyte and differentiation of episperm.The results showed that:(1) Ovule differentiated into nucellar,integument and ovule bracket 2 days after pollination.Both micropyle 162.16 μm in diameter and micropylar canal 540.54 μm in length formed at the integument peak.Meanwhile,ampuliform pollen chamber nearly 520.83 μm in length,125.06 μm in max-diameter formed at the nucellar peak.Pollen grain stayed in pollen chamber after acrossing micropylar canal.(2)The development of female gametophyte experienced free nucleus stages(5～30 days after pollination) and cellular stages(30～45 days after pollination),and then archegonia was formed near the micropyle.The other part of gametophyte developed as endosperm cell parenchyma,which nutritive material accumulate reached peak within 60～80 days after pollination.(3) The differentiation and formation of episperm experienced stages of integument differentiation(within 30 days after pollination),stages of episperm differentiation(30～50 days after pollination),initial stages of episperm formation(50～80 days after pollination) and stages of episperm formation(80～90 days after pollination).更多还原