Flower vascularization and fruit developmental anatomy of quinoa (Chenpodium quinoa Willd) Amaranthaceae

Abstract

The floral anatomical structural and developmental features of seeds and fruits of quinoa (Chenpodium quinoa Willd) cv. Hualhuas were studied using light microscope with the purpose to elucidate their structure and to contribute ecological studies of the species. The plants produce panicle inflorescences having hermaphrodite and pistillate flowers. The hermaphrodite flower possesses: 5 imbricate sepals; 5 antisepalous stamens; its filaments extend laterally forming a ring of nectariferous tissue surrounding the ovary having modified stomata. The gynoecium is bicarpellate with unilocular ovary having a single campylotropus ovule. The basal part of the ovary contains two dorsal carpellary bundles one is small towards the posterior side the other is large towards the anterior side. Whereas the ventral carpellary bundles of the two carpels occurring in the center of the ovary base and consist the vascular supply of the ovule. The dorsal posterior bundle terminates with the appearance of the locule. The ovule attach with the basal placenta on the anterior side of the ovary. The posterior carpel is sterile and reduced whereas the anterior one is fertile. The nutrients movement into the seed takes place through the high selectivity phloem elements embedded in the vascular strand of the funiculus. The collapsed outer layer of the pericarp in mature fruit could reshaped and regain turgor pressure after soaking in water, this may help for rapid germination. Although quinoa has thin seed coat layers however it have thick cell walls could maintain the moisture of embryo and perisperm and increase seed hardness as response to the arid habitats.