THE DEVELOPMENT OF THE ACHENE OF POLYGONUM PENSYLVANICUM: EMBRYO, ENDOSPERM, AND PERICARP
THE DEVELOPMENT OF THE ACHENE OF POLYGONUM PENSYLVANICUM: EMBRYO, ENDOSPERM, AND PERICARP
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宾夕法尼亚蓼的瘦果发育：胚、胚乳和果皮
DOI：
10.1002/j.1537-2197.1971.tb10016.x
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发表时间：
1971
影响因子：
3
通讯作者：
Benedict F. Neubauer
中科院分区：
文献类型：
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作者：
Benedict F. Neubauer
本文研究了盆蓼瘦果的个体发育。从受精到成熟原胚被分类为蓼属变异，星形类型。子叶在开花后三天开始形成，到第五天，原形成层出现在胚轴中。开花后约7天，胚开始弯曲并占据子房的边缘位置。到第十天，第一个叶原基在胚的茎尖发生。成熟时，胚由两片子叶、一个由茎尖和一个叶原基组成的胚芽和一个具有发育良好的胚根的下胚轴组成。胚乳核在合子第一次分裂前开始分裂。细胞壁的形成始于胚囊珠孔端的胚乳，并向合点区发展。到第五天，胚乳除了基部突起外，完全是细胞状的，并且外围分生组织已经建立。大约10天时，外围分生组织停止平周细胞分裂，变成糊粉层。在受精时，子房壁的细胞层已全部完成。最外面的细胞壁拉长并卷曲。随后这些细胞壁的加厚和木质化产生成熟瘦果的硬外果皮。自从植物栽培开始以来，杂草造成的经济损失就一直很重要。杂草在受干扰的土地上生存和竞争能力的特征包括快速生长、产生大量种子、延长种子休眠和零星萌发。红蓼（Pennsylvania sartweed）具有这些特征。这一年生杂草生长沿着沟，在潮湿的草地，废弃的地方，和耕地。这种植物的生殖或传播单位是瘦果，通常被错误地称为种子。尽管有大量关于蓼科成员胚胎发育早期阶段（Soubges，1919 a，B，1920 a，B，1924; Lonay，1922; Mahony，1936）以及后期阶段（Stevens，1912; Woodcock，1914; Lonay，1922）的研究报道，但尚未发现关于P. pennicum胚胎发育的解释。在成熟瘦果的食物储备我收到出版1971年1月27日。博士学位论文部分达到博士学位要求的论文的一部分在艾姆斯的爱荷华州州立大学获得学位。作者对约翰·E·史密斯博士表示衷心的感谢。萨斯在整个调查过程中提供了宝贵的指导和批评。感谢大卫W博士。他为这次调查提供了植物材料。这项研究得到了爱荷华州州立大学农业和家政学实验站1589项目的部分支持。Staniforth，项目负责人;并由国家科学基金会暑期助教奖学金，1964年。期刊论文编号J-6819，爱荷华州农业和家政学实验站，艾姆斯。据报道，该科植物为外胚乳（Harz，1885; Coulter和Chamberlain，1903; Eames，1961）或胚乳（拉伯克，1892; Dammer，1893; Kraemer，1910; Winton和Winton，1932; Esau，1965）。Stevens（1912）、Woodcock（1914）和Lonay（1922）描述了该科几个成员的胚乳发育。Harz（1885）和Kraemer（1910）描述了几个属成熟果壁的结构。1895年，Sasserine描述了P. pennicum和其他几种Polygonaceae的果实壁的细胞排列。Winton和Winton（1932）描述并举例说明了旋花的成熟果皮。说明了P. pennicum的果壁是相似的。关于该属果皮发育的唯一报道是Lonay（1922）在扁桃腺（P. aviculare L.）LaCroix（1961）利用胚培养、层积和电子显微镜技术研究了P. pennicum新鲜收获和贮藏的瘦果的休眠。胚的生理条件和包被结构的特点可能有助于延迟发芽。在新鲜收获的瘦果中，休眠似乎与果壁的渗透性有关。本研究跟踪研究了狼尾草瘦果从受精到成熟的个体发育过程。特别强调的是快速发育的胚，胚乳和成熟的果壁。对瘦果发育和成熟结构的了解有助于今后对渗透性的研究。
A study was made of the ontogeny of the achene of Polygonum pensylvanicum L. from fertilization to maturity. The proembryo is classified as the Polygonum Variation, Asterad Type. Cotyledons are initiated three days after anthesis, and by the fifth day procambium is present in the embryo axis. At approximately seven days after anthesis, the embryo begins to curve and occupy a marginal position in the ovary. By ten days the first foliage leaf primordium is initiated at the stem apex of the embryo. At maturity the embryo consists of two cotyledons, a plumule composed of the stem apex and one leaf primordium, and a hypocotyl with a well-developed radicle. Endosperm nuclei begin to divide before the first division of the zygote. Cell wall formation begins in the endosperm at the micropylar end of the embryo sac and proceeds toward the chalazal region. By the fifth day the endosperm is completely cellular, except for a basal projection; and a peripheral meristem has been established. At approximately ten days the peripheral meristem ceases periclinal cell division and becomes the aleurone. At the time of fertilization the ovary wall has its full complement of cell layers. The walls of the outermost cells elongate and become convoluted. Subsequent thickening and lignification of these cell walls produce the hard epicarp of the mature achene. ECONOMIC LOSSES caused by weeds have beein of importance since the beginning of plant cultivation. Among the features that account for the survival and competitive ability of weeds to thrive oni disturbed land are rapid growth, production of large numbers of seeds, prolonged seed dormancy, and sporadic germination. Polygonum pensylvanicum L. (Pennsylvania smartweed) possesses these characteristics. This annual weed grows along ditches, in damp grasslands, waste places, and cultivated ground. The reproductive or disseminating unit of this plant is an achene, often incorrectly referred to as a seed. Although numerous studies on the early stages of embryo development have been reported for members of the Polygonaceae (Soubges, 1919a, b, 1920a, b, 1924; Lonay, 1922; Mahony, 1936) as well as later stages (Stevens, 1912; Woodcock, 1914; Lonay, 1922), no developmental account has been found for the embryo of P. pensylvanicum. The food reserve within the mature achene of I Received for publication 27 January 1971. A portion of a thesis submitted in partial fulfillment of the requirement for the Ph.D. degree at Iowa State University, Ames. The author expresses his sincere gratitude to Dr. John E. Sass for invaluable guidance and criticism throughout this investigation. Thanks are extended to Dr. David W. Staniforth who provided plant material for this investigation. The research was supported in part under Project 1589 of the Agriculture and Home Economics Experiment Station, Iowa State University, David W. Staniforth, project leader; and by a National Science Foundation Summer Fellowship for Teaching Assistants, 1964. Journal Paper No. J-6819 of the Iowa Agriculture and Home Economics Experiment Station, Ames. the Polygonaceae has been reported either as perisperm (Harz, 1885; Coulter and Chamberlain, 1903; Eames, 1961) or endosperm (Lubbock, 1892; Dammer, 1893; Kraemer, 1910; Winton and Winton, 1932; Esau, 1965). Endosperm development in several members of this family has been described by Stevens (1912), Woodcock (1914), and Lonay (1922). The structure of the mature fruit wall in several genera has been described by Harz (1885) and Kraemer (1910). Sirrine (1895) described the cellular arrangement of the fruit wall in P. pensylvanicum and several other species of the Polygonaceae. Winton and Winton (1932) described and illustrated the mature pericarp of P. convolvulus L. and indicated that the fruit wall of P. pensylvanicum is similar. The only report on pericarp development in this genus is by Lonay (1922) in P. aviculare L. LaCroix (1961) used embryo culture, stratification, and electron microscopy techniques to study dormancy in both freshly harvested and stored achenes of P. pensylvanicum. The physiological condition of the embryo and features of enveloping structures can contribute to delayed germination. In freshly harvested achenes, dormancy seemed to be associated with the permeability of the fruit wall. The present study follows the ontogeny of the achene of P. pensylvanicum from fertilization to maturity. Special emphasis is placed on the rapidly developing embryo, endosperm, and maturing fruit wall. Knowledge of the development and the mature structure of the achene should aid future studies on the permeability of