银杏中种皮形态建成及结构特征

由于银杏中种皮的发育及结构与早期种仁形成、后期种核贮藏特性密切相关,本文利用半薄切片和扫描电镜观察了银杏中种皮的分化、发育过程及结构特征。结果表明,银杏授粉后不久珠被分化并形成细胞大小、形态明显差异的3个区,其中中区的5～6层细胞体积小,细胞核大,细胞排列紧密,这几层细胞即将发育形成中种皮;中种皮发育早期,细胞数目增殖速度较快,细胞质染色深,细胞核大并位于细胞的中央;授粉后70d细胞数目不再增加,此时细胞发生径向扩张,随着次生壁的形成,中种皮细胞壁开始加厚;授粉后100d中种皮细胞壁迅速增厚,细胞径向扩张加剧,细胞中央形成完整大液泡,细胞核被挤向靠近细胞壁的部位;之后细胞中液泡破裂,细胞质降解,细胞核解体消失,形成次生壁强烈增厚的多层结构;中种皮发育成熟后由大量管胞组成,根据管胞分布位置的不同可分为螺纹管胞和孔纹管胞2种,管胞侧壁均分布有大量纹孔。

Morphogenesis and structural characteristics of mesotesta in Ginkgo biloba L.

Ginkgo biloba seeds have important nutrition and medical value.Although the structure and development of mesotesta in G.biloba seeds are closely correlated to the seed kernel formation and storage qualities,the related knowledge is not too much so far.Here we used resin sections and scanning electron microscope to observe the cellular structural changes in mesotesta differentiation and developmental process.Results show that after pollination,the integument cells differentiated into 3 zones and the middle z...