Compatibilidade e caracterização em acessos de goiabeira enxertados no brs guaraçá, porta-enxerto resistente ao nematoide

Abstract

Guava is an important fruit species due to its nutritional quality and favorable cultivation conditions throughout the Brazilian territory. One of its main problems is the disease caused by the root-knot nematode, which has caused severe damage to guava-growing areas in several regions of Brazil. The present study aimed to estimate graft compatibility and characterize guava accessions grafted on the nematode-resistant BRS Guaraçá rootstock in order to guide the choice of parents for breeding and to develop and obtain new cultivars. The experiment was conducted with accessions from the Active Germplasm Bank of Psidium,Petrolina, PE. Compatibility assessments were performed for plant height, the ratio of stem diameter at 15 cm and 40 cm from the ground, and canopy diameterlongitudinally and transversely to the planting row. Fruits were analyzed for their total number, mean weight, seed weight, pulp weight, fruit diameter, and fruit length. Bioactive and physicochemical compounds were characterized by analyzing peel and pulp color, fruit firmness, soluble solids, titratable acidity, vitamin C, β-carotene, and lycopene. The data were subjected to analysis of variance, with within-plot data, and histograms were constructed based on data dispersion. None of the accessions studied showed incompatibility symptoms such as cracks, exudations, and stem diameter differences in the graft region. The accessions resulted in vigorous plants in the second production cycle, with a mean canopy diameter of 2.3 m, a mean plant height of 2.2 m, and no incompatibilities. Accessions Gua64BA, Gua181ES, Gua06MA, Pedro Sato, and Gua99AM showed the highest pulp/fruit weight values, around 160 g, whereas accessions Gua96AM, Gua70RO, Gua192ES, Gua01MA, and Gua183ES showed the highest fruit production, around 20 kg/plant. These genotypes are recommended for grafting with the BRS Guaraçá rootstock. Results were significant for all physicochemical variables, demonstrating phenotypic variability. Accessions GUA33PE and GUA135RR showed high fruit firmness and are recommended for breeding and to develop new cultivars. Accessions GUA46PE, 1,335 mg/100g-1and GUA03MA, 1,232.15 mg/100g-1, showed high vitamin C values and are recommended for breeding and developing cultivars with high contents of bioactive compounds.