Trema micrantha (L.) BLUME: fenologia reprodutiva, germinação e citogenética em área de restauração florestal no sudoeste do Paraná

Abstract

Currently, the native tree species have been much studied for the development of methodologies and the development of new technologies for recovery of degraded forest ecosystems. Trema micrantha (L.) BLUME, popularly known as grandiúva, has great importance for the recovery of degraded areas and recovery of riparian forests and is considered a pioneer of fast-growing species, which produces large amount of fruits for fauna, burlap and shading. In this sense, the present study assessed reproductive and cytogenetic aspects of species in planting area. Were accompanied by 12 selected trees planting 3 x 2 m systematic, distributed in four installments of the Experimental unit (UNEPE) "Ecological Restoration of riparian forests", located on the farm of the Federal University of Paraná, in the municipality of Dois Vizinhos. Phenological observations of individuals were collected fortnightly for analysis as for flowering and fruiting. Seeds were collected for germination test and flower buds for cytogenetic analyses. With that, the flowering and fruiting of T. micrantha was classified as extended and high annual sync, persisting from November to April, except in times of frost, where also low and high fall leaf budding. The peak of ripeness of fruit and seed dispersal is concentrated in the month of February, favored by photoperiod and temperature elevation. The resumption of vegetative growth of T. micrantha occurs from the month of September. It was observed that the species presents 288,989 seeds per kilogram and water content ranging from 7.1 to 8.9%. The germination of seeds proved to be slow and erratic, starting from the 12th day after sowing, reaching a maximum of 32%. The determination of the number of chromosomes was possible only for an array, being 10 chromosomes in bivalent Association (2n = 20). And pollen viability was high for all of the arrays of T. micrantha analyzed.