灵武长枣果实发育结构特征研究

Structure characteristic of developmental fruit of Ziziphus jujuba cv. Lingwuchangzao

关键词:  灵武长枣  果实发育  结构特征

Key words:  Ziziphus jujuba cv. Lingwuchangzao  fruit development  structure characteristic

摘要:

采用石蜡切片法,研究不同发育时期灵武长枣果实的结构特征。结果表明:(1)缓慢生长期细胞增长缓慢,外果皮细胞5～6层,表皮细胞由1层薄壁细胞构成,呈长矩形或长椭圆形,表皮细胞以内的薄壁细胞不断增生,形成内表皮细胞。果实体积增大伴随着空腔的出现,中果皮维管束数量多;(2)第一次快速生长期细胞增长迅速,表皮细胞排列疏松,中果皮中的空腔增大速度最快,维管束主要分布在靠近外果皮和内果皮的中果皮部位;(3)减缓生长期表皮细胞变成圆形或椭圆形等不规则形状,细胞排列松散,内表皮细胞形状、大小不一,细胞排列疏松。中果皮中的空腔继续增大,维管束数目逐渐减少,但变化幅度较小;(4)第二次快速生长期外果皮细胞层数减少到3～4层,表皮细胞和内表皮细胞难以区分,空腔随着果实体积的增大达到最大,许多细胞单列排成网状结构,形成更大的腔,果皮中的维管束分布最少。在灵武长枣果实发育过程中,不同发育时期的不同部位其果实的形态解剖特征不同。

Abstract:

The structure characteristics in different development stages fruit of Ziziphus jujuba cv. Lingwuchangzao were studied by paraffin section techniques. The results were as foollows:(1)In slow growth period,the cell grown slowly,the exocarp was made up of 5 ～ 6 layers of cells. The epidermises cells constituted of one layer parenchyma cells and they were rectangular or elliptical. The parenchyma cells gradually increased inside the epidermis and formed sub-epidermal cells. The size of cavity appeared when the volume of fruit had been enlarging. The mesocarp had many vascular bundles;(2)The cells grew quickly in the first rapid growth period. The epidermis cells arranged looser. The increasing speed of cavity in the mesocarp was the fastest. The vascular bundles mainly existed in the mesocarp which was near the exocarp and endocarp;(3)The epidermises in step-down growth period were some rounded or elliptical cells and they became looser. The shape and volume of sub-epidermal cells were different and they arranged chaos. The size of cavity continued to increase and the vascular bundle became less and less in the mesocarp;(4)The exocarp cells reduced to 3～4 layers,epidermis cells and the sub-epidermal cells were difficult to distinguish in the second rapid growth period. The size of cavity gradually increased with the volume of fruit increasing,many cells singly arranged and became a net and finally formed a larger cavity. The number of vascular bundles were the least in the peel. In the course of Lingwuchangzao fruit development,whatever in different development stages or different locations,the morphological anatomical characteristics of fruit were dissimilar.