Frutos, sementes e desenvolvimento plantular de três espécies de Parkia R. Br. (Fabaceae-Mimosoideae): uma abordagem morfoanatômica, histoquímica e tecnológica

Abstract

Parkia species are representative of the Amazonian floristic landscape and occupy an important role among leguminous trees. Despite the importance of species for reforestation projects, there are few reports on morpho anatomical technological in the gender, which require more detailed studies. This study aimed to characterize the morphology of fruit, morpho anatomy and histochemistry of the seeds and seedlings, as well as the technological characteristics of the seeds, in order to obtain standards for the proper management of species reproduction of Parkia multijuga, P. panurensis and P. velutina. The fruits were collected along the Urucu river at the Pedro de Moura Geologist Operations Base, Coari / AM, located at 623 km from Manaus. The physical tests indicated that seeds of P. multijuga had a weight of 1000 mature seeds equivalent of 3,432.6 g, whereas P. panurensis 712.10 g and P. velutina 521.31 g. The number of seeds per kilogram was 291 seeds for P. multijuga, 1404 for P. panurensis and 1918 for P. velutina. To determine the water content of seeds of P. multijuga three cut seeds by subsample can be used five for P. velutina. and 25 for P. panurensis. The three species have type of fruit nucóides vegetables, dry, estenocárpicos, uniseriate.The seed is oblong in P. multijuga, elliptical in P. panurensis and oboval in P. velutina. The integument presents palisade layer with clear line and printed on both sides pleurogram apical-basal, regular, 100 and 90% in P. multijuga and 90% in P. panurensis and P. velutina. Cotyledons, cloven with hidden rootlet in P. multijuga and P. panurensis and carved in radicle exposed to P. velutina. Radicle hypocotyl axle with well differentiated plumule in the three species, but only P. velutina presents axle with rachis of leaf prime with multicellular trichomes got from the tricellular base. In the mature seeds of three species, there is the presence of phenolics and alkaloids, which may be related to the mechanism of dormancy, while, carbohydrates, proteins and lipids, are the major reservations.The treatments of mechanical scarification with emery electric on the side of the seed were effective in overcoming physical dormancy of seeds of P. panurensis and P. multijuga, while the chemical scarification with sulfuric acid in a longer period of immersion was more effective for seeds of P. panurensis and P. velutina. The full seedling formation from 18 to 21 days in P. multijuga and 12 to 15 days in P. velutina and P. panurensis. The root of P. multijuga is polyarc and presents primary growth, since the P. panurensis and P. velutina present beginning of secondary growth with fascicular and interfascicular exchange both installed. Phenolic compounds were detected in the epidermis and pericycle of the root, the peripheral cortical parenchyma and epidermis of the hypocotyl, cotyledons of P. panurensis and in the pinnae of the three species.