Métodos de propagação vegetativa de Anacardium othonianum utilizando solução antioxidante e câmara úmida

Abstract

The cashew tree culture has significant socioeconomic relevance for the Brazilian Northeast. Given this importance, the Active Bank of Cajueiro Germplasm was established, being most of the accesses of the species Anacardium occidentale L., but also other species, important for expansion of the genetic base of this culture, like the Anacardium othonianum Rizz. Currently the accesses are being replanted in a contiguous area, aiming at their rescue and rejuvenation. Cloning is done by grafting for the accessions of A. occidentale, however, there is no viable methodology for the accesses of the species A. othonianum. In this context, the objective was to evaluate the viability of grafting techniques, observing the compatibility between genotype-crown and root-graft genotype and cutting, aiming to identify and correlate differences between anatomical and metabolic profiles in the propagation of species A othonianum. For the cutting experiment, cuttings of two accessions of A. othonianum (B 144 and B 626) and one cultivar A. occidentale (CCP 76) were submitted to treatments with and without antioxidant solution incubated with and without a humid chambre. Stakes were evaluated for anatomical aspects (optical microscopy and scanning electron microscopy); and its extracts were submitted to the chemometric analysis. In the grafting experiment, the aforementioned accessions, treated with antioxidant solution and B 194 and B 626 (A. othonianum) and cultivar CCP 06 (A. occidentale) were used as grafts as grafts. The survival rate and growth rates of both cuttings and grafted seedlings were also evaluated. In general, the stakes treated with antioxidant solution showed more intact tissues, less oxidized, but without success in rooting. The cuttings darkened and dried gradually until mortality, making impossible the statistical analysis of the data. From microscopy images, the oxidation and disintegration of meristematic tissues were evidenced, even in areas of visible mitotic multiplication, and from the chemometric analysis, differences were observed in the metabolic composition between the treated and untreated stakes with antioxidant solution. For grafting, regardless of the rootstock used, the B 144 access seedlings did not survive and the B 626 survival rate was low in relation to the CCP 76. Within the experimental conditions, it was concluded that the cutting was not viable for ransom of accesses of the species A. othonianum. The use of antioxidant solution reduces the degradation of cuttings, but not enough to promote rooting. It is possible to obtain clones from some accessions of A. othonianum by lateral grafting, when the graft-supplying plant has stem characteristics and less lignified branches.