Micro-cutting propagation of Eucalyptus grandis x E. urophylla through clumps of axillary buds using different containers and substrates

Abstract

This study aims to evaluate the micro-cuttings production in the micropropagation system via clumps of axillary buds in a clone of Eucalyptus grandis x E. urophylla, subjected to different types of containers and substrates. Clumps with six to eight differentiated buds of Eucalyptus grandis x E. urophylla established in vitro were used to test containers (polypropylene pot - 500 ml, glass flask - 250 ml; acrylic flask with gas exchange (AFGE) - 250 ml; and test-tube - 55 ml capacity) in a semisolid medium specific for Eucalyptus in a period of 35 days. For the substrates test, acrylic flask with gas exchange (AFGE) were used with different substrates (agar, average particle size vermiculite, and vermiculite: cellulose fiber in a 2:1 ratio) in a period of 35 days. The tests were installed in a completely randomized design (CRD). We evaluated the number of shoots larger than 0.5 cm per clump of bud, the number of micro-cuttings produced larger than 2 cm, the length of the longest micro-cutting (cm) and shoot vigor. Based on the obtained results, it was possible to observe that the best container to produce micro-cuttings larger than 2 cm was the polypropylene pot (500 ml). Glass flask (250 ml) was more advantageous to achieve greater production of micro-cuttings per square meter due to its capacity of better densification. The best substrates to produce micro-cutting larger than 2 cm using acrylic flask with gas exchange (AFGE) containers were agar or vermiculite.