Microsatellite variation in Avena sterilis oat germplasm

Area of Science:

• Plant genetics
• Crop science
• Molecular biology

Background:

• The Avena sterilis L. collection at PGRC is a vital genetic resource for oat improvement.
• Inadequate characterization, especially using molecular markers, limits its full potential.
• Understanding genetic diversity is crucial for identifying valuable traits like disease resistance.

Purpose of the Study:

• To molecularly characterize a structured sample of Avena sterilis L. accessions using microsatellite (SSR) markers.
• To assess and compare the genetic diversity within and among accessions from different countries.
• To investigate the genetic basis of resistance to oat crown (Pc) and stem (Pg) rusts.

Main Methods:

• Utilized 26 informative SSR primer pairs to screen 369 Avena sterilis L. accessions from 26 countries.
• Scored 125 alleles across all accessions to analyze genetic variation.
• Employed stratified sampling to capture country-wise SSR variation.

Main Results:

• SSR analysis revealed that over 90% of genetic variation resided within accessions of a single country.
• Accessions from Greece, Liberia, and Italy showed the highest genetic diversity.
• Distinct genetic clusters were identified, not strictly correlating with geographic origins.
• Accessions with Pc and Pg resistance genes exhibited similar variation levels and did not cluster separately.

Conclusions:

• Microsatellite markers effectively characterized Avena sterilis L. germplasm, revealing significant genetic diversity.
• Stratified sampling proved efficient for capturing SSR variation.
• Findings provide insights into oat progenitor species, germplasm management, and novel gene discovery for oat breeding.