Semente, germinação e desenvolvimento inicial de plântulas de Bactris maraja Mart. (Arecaceae): aspectos morfoanatômicos, histoquímicos e tecnológicos

Abstract

Bactris maraja Mart ., commonly known as maraja, is a palm native to the Amazon use little known. However, the trunks are used by traditional construction of corrals fishing. The fruits are edible, being consumed by humans, and especially the wildlife. Studies with palm trees in the areas of technology and morphoanatomic have been conducted, however, the peculiarities inherent to the species of the family Arecaceae, difficult material handling. This research aimed to examine seeds of B. maraja regarding the structure and physiological quality, as well as describe the morphology development and germination plantular, beyond morphoanatomy seedling. The clusters containing mature fruits were collected from 25 individuals in floodplain environment in the municipality of Careiro Lowland, Amazonas. Pyrenes and the seeds had a water content of 23,1 % and 17,9 %, respectively. The pyrene is oval to elliptical, with core disk formed by sclerified cells thick-walled, however, absent in the region of the germ pore. The seed is eurispermica, being cordate, oblong and elliptical. Shows two to three pores. The integument is thin, consisting of sclerenchyma cells and thickened with phenolic content. The endosperm is homogeneous, white and rigid. The embryo is apical, small, tapered and milky-white, with-embryonic axis oblique and curved, with three leaf primordia. The endosperm storage protein and lipid reserves. The alternating temperature of 26-40 °C was suitable for seed germination, regardless of the level of processing. The progressive drying of pyrene facilitated the extraction of seeds. However, drying and removal of the endocarp reduced germination and vigor. Therefore, the processing is not recommended. The seed soaking for two days enhanced germination. The seed dormancy is not caused by the presence of the endocarp. Germination is adjacent ligulate, cryptocotylar and hypogeal. Started at 152 days after sowing, with protrusion of the cotyledon petiole, forming the germinal button to 160 days. The seedling completed the development to 273 with the depletion of the haustorium. The eophyll is bifid, with tetracytical stomata, multicellular trichomes and collateral vascular bundles. The root shows thick epidermis, cortex sclerenchymatous and parenchymatous, endoderm conspicuous; polyarc is with hollow vascular cylinder with spinal sclerenchymatic.