Unravelling Pea-Ascochyta Blight Interaction and Its Implications for Pea Breeding

Area of Science:

• Plant Pathology
• Agronomy
• Genetics

Background:

• Ascochyta blight, caused by necrotrophic fungi, is a major global constraint on pea (Pisum sativum L.) production.
• Understanding the pea-Ascochyta blight pathosystem is crucial for maintaining crop yield and quality.

Purpose of the Study:

• To review current knowledge on the genetic, physiological, and molecular aspects of the pea-Ascochyta blight pathosystem.
• To emphasize the genetic architecture of resistance, host defense mechanisms, and omics contributions.
• To critically discuss the utility of molecular markers for breeding programs.

Main Methods:

• Literature review synthesizing genetic, physiological, and molecular data.
• Analysis of host-pathogen interactions and resistance mechanisms.
• Evaluation of omics contributions and marker-assisted selection (MAS) and genomic selection (GS) strategies.

Main Results:

• Genetic resistance to Ascochyta blight is incomplete, multicomponent, and influenced by loci with small to moderate effects.
• Resistance expression is modulated by plant organ, developmental stage, and environmental conditions.
• Field phenotypes result from complex interactions between physiological resistance, plant traits, and epidemic dynamics, impacting marker transferability.

Conclusions:

• Breeding for Ascochyta blight resistance requires integrating molecular insights with precise ideotype definition, robust phenotyping, and multi-environment validation.
• Current molecular markers have practical value but require careful application in marker-assisted selection (MAS) and genomic selection (GS).
• Future advancements in Ascochyta blight resistance breeding depend on a holistic approach combining genetics, phenotyping, and field validation.