Resistance induction to Fusarium guttiforme in pineapple genotypes in the city of Tangará da Serra Mato Grosso
Disease, fusariosis, plant resistance, biotic and abiotic inducers
In Brazil, the cultivation of pineapple has grown considerably, but fusariosis, considered as the main disease of this culture, has been causing high losses in production. Thus, the present study aimed to evaluate the efficiency of resistance inducers applied in cultivars to control pineapple fusarium disease, as well as to verify their influence on the vegetative characteristics of the cultivars. The treatments were used: T0 - absolute control; T2- acibenzolar-S-methyl (ASM) 0.4gL-1; T3- Bacillus subtilis 1x109 UFC mL-1; T4-ecolife® 0.2 mL-1; T5- acibenzolar-S-methyl (ASM) 0.4gL-1 + Bacillus subtilis 1x109 UFC mL-1 + and T6- ecolife® 0.2 mL-1 + Bacillus subtilis 1x109 UFC mL-1. The experimental design used was randomized blocks in a 6x2 factorial arrangement (6 treatments and two cultivars (one resistant and the other susceptible), containing 3 replicates, each plot with 5 plants, in which the same plants were used for enzymatic analysis, as well as to analyze the severity of the disease, two plants of each replicate per cultivar were used to evaluate the dry matter. The collections for enzymatic analysis of peroxidase, polyphenoloxidase, phenylalanine ammonia lyase, β-1,3-glucanase and total proteins were performed at 24, 48, 72, 96 and 120 hours after inoculation of Fusarium guttiforme. All inductors evaluated provided increases in the activity of peroxidase, polyphenoloxidase, β-1,3 glucanase and phenylalanine ammonia lyase, but only ASM, PBC and Bacillus subtilis + PBC were efficient in controlling fusariosis, in addition, the plants of the resistant cultivate (BRS Imperial) showed less severity and less Area Under the Curve of Severity of Disease Progress (AUDPC) when compared to the plants of the susceptible cultivate (Pérola). All inductors provided an increase in the dry mass in the aerial part to cultivate Pérola. There was no influence of inductors on the other vegetative characteristics evaluated.