‘Fresno Seedless’葡萄幼胚和胚乳发育及败育的组织学观察

Observation of Development and Abortion Process of Embryo and Endosperm in ‘Fresno Seedless' Grape

以种子败育型无核葡萄品种‘Fresno Seedless’为试材,采用石蜡切片技术和铁矾媒苏木精染色法,对‘Fresno Seedless’葡萄的幼胚和胚乳的发育及败育过程进行了系统的细胞学观察,以期确定其幼胚和胚乳开始败育的时期。结果表明:‘Fresno Seedless’葡萄合子于花后16d开始分裂,经过二细胞原胚、多细胞原胚,发育至球形胚时期,开始退化败育,时间为花后38d;‘Fresno Seedless’葡萄初生胚乳核于花后6d开始分裂,待胚乳细胞基本充满胚囊后开始退化败育,时间为花后32d。胚囊内胚乳首先从胚囊珠孔端开始败育,随后合点端胚乳开始败育。因此,‘Fresno Seedless’葡萄的胚挽救最佳取样时期是花后32～36d。该研究结果为利用‘Fresno Seedless’葡萄做母本进行胚挽救育种的大田取样时期提供了较为科学的参考依据。

Cytological observation of development and abortion of embryo and endosperm in 'Fresno Seedless' grape was conducted by paraffin section technique and dyeing to research for the start time of abortion of embryo and endosperm via paraffin section and Iron-vitriol hematoxylin staining.The observation results indicated that the embryo abortion of 'Fresno Seedless' grape occurred at the globular embryo stage on 38 days AFB(days after full blooming)after the initial division of zygote on16 days AFB and following development at the two-celled proembryo stage and the multicellular proembryo stage.The endosperm nucleus began to divide on 6days AFB and stopped on 30 days AFB when the embryo sac was full of cellular endosperm.The endosperm started to degenerate on 32 days AFB and the abortion generated from the micropylar end to chalazal end in embryo sac.It could be concluded that the optimal time of embryo rescue choosing 'Fresno Seedless' as female parent was32-36 days AFB.This study provided a scientific reference to the sampling time of embryo rescue to breed in field.