Resistance of Arabica coffee cultivars to leaf wounds and Pseudomonas syringae under field conditions

Abstract

The aims of this study were: (a) to evaluate the resistance of coffee cultivars to Pseudomonas syringae (PS); (b) verify if there are coffee genotypes that present less wounds on the leaves; (c) to study the correlation between amount of wounds and PS severity. The field trial was installed in April 2014 at the IAPAR’s experimental station (Londrina, Paraná, Brazil). 18 Arabica coffee cultivars were evaluated. The cultivars Mundo Novo IAC 376-4 and Catuaí Vermelho IAC 81 were the susceptible controls and IPR 102 was the resistant control. After 32 months of planting the field trial, resistance to PS was evaluated in December 2016. The evaluation of the PS severity was carried out under conditions of natural infections of P. syringae pv. garcae and P. syringae pv. tabaci based on the symptoms, using a grading scale from 1 to 5. The number of wounds on the leaves of the eight cultivars were counted. The results showed that IPR 102 was resistant to Pseudomonas syringae, whereas IPR 99, Arara, IPR 107, Acauã, Sabiá, Catucaiam 24137, Japy and Catuaí Vermelho IAC 81 were susceptible. Mundo Novo and Catucaí Amarelo 2SL were more susceptible than Catuaí Vermelho. IPR 106, Japiam, Catiguá MG 2, Catiguá MG 1 and IBC Palma 2 showed moderate resistance, while IPR 103 and Catucaiam 2015479 were moderately susceptible. The cultivars IPR 102 and IPR 106 presented resistance to wounding because they had lower wounds than other cultivars. Increased leaf wounds was associated with increased P. syringae severity.

Resistance of genotypes and defence compounds against bacterial halo blight of coffee

“…The results of severity of cultivars IPR 102 and Mundo Novo 376/4, considered resistant and susceptible to BHB, respectively, in this study, confirmed this classification of resistance to BHB, as verified in other studies (Ito et al., 2008; Sera et al., 2017; Rodrigues et al., 2019; Fernandes et al., 2020). Among the evaluated genotypes from the germplasm bank to BHB resistance, eight genotypes showed disease severity similar to cultivar IPR 102, for example, UFV 7158 genotype and Catiguá MG2 cultivar.…”

“…Catiguá MG2 cultivar is resistant to rust (Carvalho et al., 2017; Del Grossi et al., 2013) and showed moderate resistance to cercosporiosis in coffee seedlings (Botelho et al., 2017). Fernandes et al (2020) evaluated the BHB severity under field conditions and this cultivar showed moderate resistance to disease, although inoculation methods may influence the response of coffee genotypes to BHB. Rodrigues et al (2016) compared sprinkling and multiple needles methods and the abrasion technique for resistance tests of BHB on coffee.…”

Management of bacterial halo blight and other coffee crop diseases

“…On the other hand, more than 35.5 hours of leaf wetness were necessary for BHB to occur in non-wounded plants. FERNANDES et al (2020) showed a positive correlation between injuries and BHB severity in coffee crops in Paraná State.…”

Combining Ability and Molecular Marker Approach Identified Genetic Resources to Improve Agronomic Performance in Coffea arabica Breeding

“…In addition, Catiguá MG2 has been used as a source to enhance cup quality and obtain specialty coffee (Alex et al, 2016;De Paiva Barbosa et al, 2019b). This cultivar has also been highlighted for its high resistance to CLR (Del Grossi et al, 2013) and moderate resistance to bacteriosis caused by Pseudomonas syringae (Fernandes et al, 2020).…”