Genetic analysis of partial resistance to coffee leaf rust (Hemileia vastatrix Berk & Br.) introgressed into the cultivated Coffea arabica L. from the diploid C. canephora species

Abstract

The objective of this study was to identify polymorphic molecular markers associated with partial resistance to coffee leaf rust, Hemileia vastarix. A segregating F 2 population derived from a cross between the susceptible Coffea arabica cv. Caturra and a C. canephora-introgressed Arabica line exhibiting high partial resistance was analyzed. Rust resistance measured as rust incidence (RI) and defoliation (DEF) was evaluated in field conditions in three consecutive years (2003)(2004)(2005). During the 2003 season, which was characterized by favorable conditions for a rust epidemic, the F 2 plants exhibited different levels of resistance ranging from very susceptible (50.1% for DEF and 49.5% for RI) to highly partial resistance (9.1% for DEF and 3.7% for RI). Molecular analysis enabled identification of seven polymorphic markers (5 AFLP and 2 SSR) exhibiting significant association with partial resistance. Coexistence of resistance homozygous alleles (RR) at codominant SSR loci was correlated with high resistance. This study is the first attempt to develop PCR-based sequence specific markers linked to partial rust resistance in coffee.

Microsatellite markers in analysis of resistance to coffee leaf miner in Arabica coffee

“…However, no significant correlation among the molecular markers and the presence of lesions in coffee leaves infested by L. coffeella was detected. Herrera et al (2009) evaluated the Sat 225 and Sat 229 loci in a F 2 segregating population resulting from a cross between the susceptible C. arabica cultivar Caturra and the resistant female parental hybrid derived from the cross between C. arabica and C. canephora. These authors observed the occurrence of a variable amplification pattern during the evaluated years, which may be associated with the infestation pressure of the pathogen.…”

“…In addition, 28 EST-SSR primers (Pinto et al, 2007) and three more SSR loci, already characterized for coffee biotic stress (Herrera et al, 2009) (1) CA1, non embryogenic callus; LV5, pointer leaf -orthotropic branch without Bion -short; LV9, pointer leaf -plagiotropic branches without Bion -short; RT3, root without Bion; RT5, root with Bion; CL2, hypocotyl callus with and without Bion; FR1, flower bud no. 6, lead no.…”

“…The exception is C. arabica, an allotetraploid, with 44 chromosomes, of which 22 came from C. eugenioides S. Moore and the rest from C. canephora Pierre ex A. Froehner (Lashermes et al, 1999). C. arabica has a narrow genetic base due to the small quantity of seeds originally introduced in Brazil associated with the autogamous nature of this species.…”

Components of resistance of conilon coffee that reduce the rate of leaf rust development

“…The progênies originated from clone 83 and clone 02 showed a wide spectrum levels from resistance to susceptibility. Horizontal resistance is commonly observed in C. canephora although it also occurs in some genotypes of C. arabica progenies of Híbrido de Timor (Eskes 1983;Eskes 2005;Herrera et al 2009;Romero et al 2010). Breeding programs to rust resistance have been nowadays looking for the quantitative reaction of the plant genotypes due to the vulnerability of the qualitative resistant cultivars to the emerging races of H. vastatrix.…”

High-density genetic mapping for coffee leaf rust resistance

“…The number of known markers and molecular information on coffee leaf rust-resistance genes are limited (Herrera et al 2009). To date, genetic maps saturated for C. arabica containing genes or QTLs controlling this trait have not been made available.…”