Morfoanatomia de sementes e morfometria de frutos, plântulas e do desenvolvimento pós-seminal, associados ao vigor em clones de Myrciaria dubia (Kunth) McVaugh

Abstract

Camu-camu occurs spontaneously throughout the Amazon Basin from fertile to poor soil. It has a wide adaptive plasticity. It is a fruitful in incipient process of domestication and adaptation to terra firma. It has a large economic potential. It assists in the economy of the rural inhabitants, its cultivation contributes to ameliorate the economic losses occurred due to the floods. It is known as the fruit richest in vitamin C. Fruits of native plants present disparities in vegetative and reproductive aspects. Morphometric variations are important indicators of genetic variability exploited in breeding programs. Biometrics is an important tool to detect genetic variation of populations of the same species and the relationships between this variability and environmental factors. The description of the morphological aspects of seeds and seedlings is essential, since they can help in the management, conservation and development of efficient techniques for the production of seedlings. For Myrtaceae, anatomical and histochemical studies have been performed with some emphasis on economically important cultures. The aim of this study was to describe fruits, the structures present in the stages of post-seminal development and seedlings, to describe the anatomy and to identify the main seed storage compound, as well as to evaluate the physical and physiological quality of the seeds in clones of Banco Ativo of Germplasm of Camucamuzeiro of Embrapa Amazônia Oriental. Five clones of camucamuzeiro were evaluated for morphological, biometric, anatomical and histochemical characteristics. The fruit is a globose, simple, fleshy berry. The seeds are exalbuminous, have fleshy cotyledons, crassos, soldiers, reniformes, the embryo is eugenoid, with polyembryony. Micropyle, raphe and lens are imperceptible. Germination cryptocoledonar hypogea. The seedling has a pivoting radicular system, undifferentiated hypocotyl, cylindrical and elongated epicotyl. The eofilos are simple, opposite or less frequently verticillate. The outer tegument presents epidermis composed of a layer of cells of tabular format, rich in phenolic content, pectins, alkaloids and terpenes. The cotyledons have uniseriate epidermis and parenchyma formed by polyhedral cells with a high concentration of starch grains and dispersed vascular bundles, presents alkaloids, idioblasts with phenolic content, lipids and proteins. The embryonic axis has a protoderm with cuboid cells, juxtaposed, thin walls and conspicuous nuclei. There is ample biometric variability among the studied clones thus configuring a high genetic potential. The secondary methabilites present in the species are located principally in the integument. This information can aid in the isolation of these substances for further studies.