HERITABILITY STUDIES AND DNA MARKERS FOR POWDERY MILDEW RESISTANCE IN STRAWBERRY (FRAGARIA × ANANASSA DUCHESNE)

Resistance to Powdery mildew (PM) disease causes major economic losses in strawberries. Yet, the genetic basis of PM resistance has not been well studied and, as a result, the introduction of new resistant cultivars has been limited. In this study, we aimed to reveal the genetic basis for PM resistance in the octaploid strawberry. Resistant and susceptible accessions were selected and hybridized to produce seven PM-segregating populations. In an effort to develop genetic markers associated with PM resistance, we screened 30 SSR markers, which co-segregate with PM resistance in different populations. In addition, we tested resistance gene analogs (RGAs) as candidate genes for PM disease resistance. The predicted protein alignments of 20 RGAs showed a wide range of sequence identity (35-99%) and were classified into five groups belonging to the Toll and interleukin-1 receptor (TIR) and non-TIR NBS-LRR classes.