Mourão K S, Beltrati C M
Departamento de Biologia, Universidade Estadual de Maringá, Maringá, Paraná, Brazil.
Braz J Biol. 2000 Nov;60(4):701-11. doi: 10.1590/s0034-71082000000400023.
Morphological, structural and developmental features of fruits and seeds of Mammea americana L. are here studied, with the purpose to give a proper classification of their fruit and embryo type and to contribute to future taxonomical and ecological studies. The fruit is a berry and the "rind" consists of the exocarp, represented by a periderm with lenticels, and by the parenchymatic mesocarp, with branched secretory ducts and vascular bundles. The edible pulpy is formed by the endocarp, destituted of secretory ducts, and derived from the activity of a ventral meristem, which emerges early in the fruit development. The inner endocarp cell layers undergo a radial elongation and become firmly attached to the testal outer layers. At maturation the endocarp may be released from the rest of the pericarp. The ovules are unitegmic and they turn into unitegmic and exalbuminous seeds. The multiseriate testa consists of thick-walled cells and sclerenchymatous fibers. This last features have carried out to a wrong interpretation that the fruit of this species is a drupe. The embryo is pseudo-conferruminate, with two massive foodstoring cotyledons, rich in starch, firmly attached.
本文研究了美国山竹子（Mammea americana L.）果实和种子的形态、结构及发育特征，旨在对其果实和胚的类型进行恰当分类，并为未来的分类学和生态学研究提供帮助。果实为浆果，“果皮”由外果皮组成，外果皮由具皮孔的周皮以及薄壁的中果皮构成，中果皮有分支的分泌道和维管束。可食用的果肉由内果皮形成，内果皮没有分泌道，源自腹侧分生组织的活动，该分生组织在果实发育早期出现。内果皮的内层细胞径向伸长，并与种皮外层紧密相连。成熟时，内果皮可能会从果皮的其余部分分离。胚珠为单珠被，发育成单珠被且无胚乳的种子。多列种皮由厚壁细胞和厚壁纤维组成。最后这一特征导致了对该物种果实为核果的错误解读。胚为假合点型，有两个富含淀粉、紧密相连的大型贮藏养分子叶。
