Fungos micorrízicos arbusculares e ácido giberélico no desenvolvimento inicial de genótipos de helicônia

Abstract

Studies on the heliconia species are still incipient, regarding the factors that interfere in its growth and development. In view of the above, the objective of this research was to evaluate the growth and vegetative development of heliconia genotypes, with the inoculation of arbuscular mycorrhizal fungi (AMF) in the rhizome and application of gibberellic acid (GA3). Two experiments were conducted concomitantly in the Unioeste nursery, from July 2021 to January 2022, under shaded conditions. The rhizomes of the mother plants were collected and kept together with part of the pseudostem, with an average size of 20 cm, and applied the treatments. For inoculation of the fungi, 2 kg of latosol was used, arranging the rhizomes in plastic boxes, which, after one week, were transplanted to plastic pots, containing a mixture of latosol and tanned bovine manure (1:1, v/v). The experimental design used was randomized blocks, in a 3 x 5 factorial scheme [3 genotypes: Alan Carle (Heliconia spathocircinata), Holiday (H. angusta Vellozo) and Golden Torch (H. psittacorum x H. spathocircunata) x 4 AMFs (Scutellospora heterogama, Rhizophagus clarus, Gigaspora rosea and Claroideoglomus etunicatum) + control (without inoculation)], with 3 repetitions and 3 plants per repetition. For the second experiment, two heliconia genotypes were selected, with application of GA3 concentrations in the propagating material. The experimental design used was randomized blocks, in a 4 x 2 factorial scheme [4 concentrations of GA3 (0, 400, 800 and 1200 mg L-1) x 2 genotypes of heliconia, Eden Pink (Heliconia ortotricha) and Alan Carle (H. psittacorum x H. spathocircinata)], with 6 repetitions and 1 plant per repetition, totaling 48 plants. After 60 days, phytotechnical evaluations were performed every 15 days, until 180 days, for both experiments. Independent of the AMF used, the genotype that stood out was Alan Carle. The fungi Rhizophagus clarus and Gigaspora rosea can help in the formation of the root system of the heliconia genotypes studied. Concentrations up to 400 mg L-1 of GA3 can be used in rhizomes, optimizing the initial development of the heliconia genotypes studied.