阿蒂莫耶番荔枝心皮愈合的研究

Carpel fusion of Annona × atemoya(Annonaceae)

关键词:  番荔枝科, 阿蒂莫耶, 心皮愈合, 表皮细胞, 薄壁细胞

Key words:  Annonaceae, Annona Xatemoya, carpel fusion, epidermal cell, parenchymatous cell

摘要:

阿蒂莫耶番荔枝(Annona Xatemoya)是重要的热带经济水果,心皮愈合是其果实发育的重要阶段。为了研究阿蒂莫耶番荔枝心皮愈合的器官发生特征,该文以授粉后不同发育时期的幼果为材料,利用石蜡切片技术和光学显微镜进行了观察,结果表明:(1)幼果心皮愈合的时间为授粉后1个月左右,花托顶端的心皮愈合先于底端心皮,相邻心皮愈合时,先在心皮底端靠近花托的位置发生愈合,再逐渐向花柱方向延伸,最终在柱头处发生愈合。(2)心皮愈合过程中,心皮表皮细胞的分化有两种:一是在花柱端的心皮表皮细胞分化形成薄壁细胞,心皮两两融合,无明显的边界痕迹; 二是在子房端,相邻心皮的表皮细胞去分化后分裂成4层排列紧密的类薄壁细胞,在原有的表皮部位形成一段边界痕迹。这是一种新的不完全的后发性心皮愈合类型。该研究丰富了心皮愈合的类型,增加了阿蒂莫耶番荔枝果实发育早期特征的认识,也为揭示番荔枝属心皮愈合的过程和特征提供了参考。

Abstract:

Annona Xatemoya(Annonaceae)is an important tropical economic fruit. Carpel fusion is an important stage in its fruit development process. In order to study the ontogeny of the carpel fusion of Annona Xatemoya, the present study observed its young fruits by paraffin sections and light microscopy. The results were as follows:(1)The carpel fusion of young fruit happened about one month after pollination. Carpels at the top of the receptacle fused earlier than carpels at the bottom. The adjacent carpels firstly fused near the base of carpels, gradually extended towards the style, and end at the stigma.(2)During the carpel fusion process, the fusion was caused by the dedifferentiation of carpel epidermal cells into parenchymatous cells or four layers of closely arranged special parenchymatous cells. The former happened at the style end and result in a total fusion while the latter happened at the ovary end and left a boundary marks at the original epidermal site, which is a new type and incomplete postgenital carpel fusion. These findings enrich the types of carpel fusion as well as our understanding of the early developmental characteristics of Annona × atemoya, and provide a reference for revealing the process and characteristics of carpel fusion in genus Annona.