Resistência de genótipos de citros e afins à Diaphorina citri Kuwayama, 1908 (Hemiptera: Liviidae)

Abstract

Currently, Huanglongbing (HLB) is one of the main phytosanitary problems for the citrus production chain. It causes highly significant losses in production due to the unfeasibility of commercializing the fruits. Diaphorina citri is the vector of HLB. As there is still no cure for the disease, measures to manage HLB depend on efficient control of the vector. This work was carried out with the objective of identifying promising citrus rootstock genotypes and related plants in terms of resistance to Diaphorina citri. Two experiments were carried out, the first in September and October 2015 and the second in June 2016. The experimental design was completely randomized in a factorial scheme, with 24 genotypes and 6 replications. In the first experiment, 13 assessments were carried out for the number of adults and 2 for the number of nymphs. For number of eggs, an assessment was made seven days after infestation. In the second experiment, only the number of adults was evaluated (16 evaluations). For infestation, 720 adults (Experiment 1) and 3316 adults (Experiment 2) were homogeneously distributed. The data were subjected to analysis of variance and the means were compared using the Scott-Knott test (5%). In the first experiment, a lower number of adults was observed in the genotypes TRBK (Trifoliata 'Benecke'), LCRxTR-001, HTR-069, LRFx(LCRxTR)-005, HTR-051, TSKCx(TRxLCR)-040, TSKxTRBK-CO, TSKCxCTCM 008, considered repellents. The genotypes TSKCxCTCM-008, HTR-069, LCRxTR-001, TSKCx (TRxLCR)-040, Citrandarin ‘Riverside’, LRFx(LCRxTR)-005 and TRBK (Trifoliata ‘Benecke’) showed deterrence for oviposition and no nymphs. Regarding the second experiment, Tangerineira ‘Sunki Tropical’ was the most attractive genotype. Tangerine ‘Cleópatra’ and LCRSTC(Limoeiro ‘Cravo Santa Cruz’) also remained favorites, but together with HTR-208 and TSKCx(LCRxTR)-017. The genotypes LRFx(LCRxTR)-005, HTR-051, TSKCxCTSW-028, Citrandarin 'Riverside', TSKCxCTCM-008, Citrandarin 'San Diego', LCRxTR-001, TSKCx(LCRxTR)-059, TSKxTRBK (Trifoliata 'Benecke') CO and TRBK (Trifoliata 'Benecke') were considered unattractive to the insect. There is variability in the attractiveness of rootstock genotypes to D.citri, requiring additional studies to identify the resistance mechanisms involved.