Complementary approaches to dissect late leaf rust resistance in an interspecific raspberry population

Area of Science:

• Plant Pathology
• Genetics
• Agricultural Science

Background:

• Global raspberry production is increasing, primarily from Rubus idaeus.
• Rubus occidentalis (black raspberry) shows resistance to late leaf rust (Acculeastrum americanum).
• Genetic resistance is vital for sustainable disease control due to limited fungicide options.

Purpose of the Study:

• To elucidate the genetic architecture controlling late leaf rust resistance in raspberries.
• To identify genomic regions and candidate genes associated with resistance.

Main Methods:

• Utilized an interspecific multiparental population derived from Rubus idaeus and Rubus occidentalis.
• Employed genome-wide association studies (GWAS) and copula graphical models for genetic analysis.
• Applied high-throughput multispectral imaging and traditional disease scoring for phenotyping.

Main Results:

• Identified a major quantitative trait locus (QTL) at 13.3 Mb on chromosome 5 associated with late leaf rust resistance.
• Both GWAS and network analysis pinpointed this significant genomic region.
• Discovered candidate genes within the resistance locus, including potential receptors and defense executors.

Conclusions:

• A major genetic locus on chromosome 5 significantly contributes to late leaf rust resistance in raspberries.
• Integrated genomic and network approaches enhance understanding of complex disease resistance.
• Findings provide a foundation for breeding disease-resistant raspberry varieties.