Resistance to bacterial halo blight in Arabica coffee lines derivative from the genotype C1195-5-6-2 under natural infection conditions

Abstract

The aim of this study was to identify resistance to bacterial halo blight in Arabica coffee lines carrying Coffea racemosa genes. Eighteen Arabica coffee lines derivative from the genotype C1195-5-6-2, and the cultivars IAPAR 59 and IPR 99 were evaluated for resistance to bacterial halo blight in two trials carried out in field conditions, in Londrina, PR, Brazil. The cultivars Mundo Novo IAC 376-4 and Catuaí Vermelho IAC 81 were included as susceptible controls. Ten lines and the cultivar IAPAR 59 showed resistance to bacterial halo blight. The cultivar IPR 99 presented intermediate reaction, and the controls were very susceptible. This is the first study to show that lines derivative from the genotype C1195-5-6-2, which has C. racemosa genes, could be a source of resistance to bacterial halo blight in coffee breeding programs.

Chemical Composition, Production of Secondary Metabolites and Antioxidant Activity in Coffee Cultivars Susceptible and Partially Resistant to Bacterial Halo Blight

“…The Mundo Novo and Iapar-59 cultivars showed variation in disease severity, as reported by Andreazi et al [ 22 ], who evaluated the resistance to BHB in trials performed under field conditions. According to the authors, the disease severity in Mundo Novo was five to ten times more than in Iapar-59.…”

“…Among the coffee ( Coffea arabica L.) cultivars planted in Brazil, the Mundo Novo 376/4 cultivar corresponds to almost half of the planted area. This cultivar is susceptible to main coffee diseases, including BHB [ 21 , 22 ]. The Iapar-59 cultivar has an intermediate level of resistance to BHB [ 23 , 24 ] and is resistant to coffee leaf rust ( Hemileia vastatrix ) [ 23 , 25 ].…”

Management of bacterial halo blight and other coffee crop diseases

“…Other cultivars derived from the Timor Hybrid (natural cross between C. arabica x C. canephora) showed resistance to BHB, such as Ruiru II, Rume Sudan, and Bastian in Kenya, and some genotypes in Brazil (ITHIRU et al 2013, ITHIRU et al 2016, ANDREA-ZI et al 2018. Other species of the genus Coffea may also be sources of BHB resistance, such as C. eugenioides, which is a resistance source to leaf miner (Leucoptera coffeela) (MOHAN et al 1978, ANDREAZI et al 2018RODRIGUES et al 2019); as well as Coffea stenophila, C. liberica, C. canephora, C. congencis andC. salvatrix (MOHAN et al 1978, RODRIGUES et al 2019).…”