Conteúdo de DNA e caracterização anatômica de cultivares de oliveiras (Olea europea L.)

Abstract

Due to the expansion of olive cultivation in Brazil and the high number of varieties, characterization studies of cultivars are fundamental. This study aimed to characterize the internal morphology, quantify anatomically the foliage and estimate the DNA content of six olive cultivars in the Banco de Germoplasma da Epamig Sul de Minas. For the anatomical analysis, fully expanded leaves of olive trees were cut into cross sections and evaluated for epidermal thickness of adaxial and abaxial faces, thickness of palisade and spongy parenchyma and thickness of the mesophyll and midrib. Were recorded 128 photomicrographs, 64 of the leaf blade and 64 of the midrib, divided into four replication. For DNA content, approximately 70 mg of leaf tissue were grounded with Glycine max (internal reference standard) into a Petri dish containing 1 ml of buffer Marie. The nuclei suspension was filtered through 50 μm and stained in addition of 15 µL with propidium iodide for every sample. For each treatment, three samples of ten thousand nuclei were analyzed on Facscalibur cytometer (Becton Dickinson). The DNA content of olive cultivars ranged from 2.54 to 2.89 pg. The basic structure of olive cultivars is the same for different cultivars, however, there are differences concerning the thickness of leaf tissues, the midrib and in the mesophyll.