MÉTODOS DE PROPAGAÇÃO VEGETATIVA DE GUAVIRA (CAMPOMANESIA ADAMANTIUM (CAMBESS.) O. BERG)

Abstract

ABSTRACT The guavira (Campomanesia adamantium Cambess O. Berg) is a native species of the Myrtaceae family that occurs in cerrados. Its fruits are consumed in natura at harvest time but can be processed as jellies, ice creams and liqueurs. Because it is a species considered to have commercial potential and interest in cultivation and environmental restoration, we aimed to evaluate two forms of vegetative propagation through stool layering and root cuttings. Stool layering was performed in the four yearly seasons and with five doses of indol butyric acid (IBA): 0, 1500, 3000, 4500, and 6000 mg kg-¹, in randomized blocks, factorial arrangement 5 x 4 (IBA doses x seasons) with 5 replications, with two plants per plot and 4 layers per plant, totaling 400 in 100 matrices. Occurred formation of calluses and buds, with higher percentages in spring and summer. In the anatomical study, buds and calluses were examined under light microscopy. Some layers produced shoots with adventitious leaves and roots in stem mature tissue, the pericycle. Stem branches showed secretory cavities in the peripheral portions and early secondary growth with periderm, secondary vascular system, and abundant phenolic compounds. However, the percentage of layers with adventitious roots was low, regardless of season and IBA dose. We concluded that the vegetative propagation of C. adamantium by layering is not a viable practice. Therefore, we tested 5 cm long underground structure cuttings in a completely randomized design in a factorial arrangement 2 (positions) x 5 (IBA doses), with 4 replications of 5 cuttings per plot, totaling 200. We found that the positions (horizontal and vertical) of cuttings interfered significantly with the average shoot number, with (3.0 b) for the horizontal and (5.05 a) for the vertical, and root dry weight with (0.59 a) for the horizontal and (0.22 b) for the vertical. Duncan's test (5% probability) did not detect differences in the IBA application. We made slides from 200 evaluated cuttings with a sliding microtome, stained them with toluidine blue and observed their morphology under light microscopy, identifying 2 stems and 198 roots. For the first time, we found that C. adamantium can be propagated by cuttings of underground structures, being a favorable alternative for seedling production. Keywords: Cerrado, Cutting, Layering, Native fruit, Plant Anatomy