ARS | Publication request: Preliminary Genetic Map of Hydrangea macrophylla Using SSR Markers and a Pseudo-Testcross Strategy

Submitted to: International Hydrangea Conference
Publication Type: Abstract Only
Publication Acceptance Date: August 10, 2007
Publication Date: August 19, 2007
Citation: Rinehart, T.A., Reed, S.M. 2007. Preliminary Genetic Map of Hydrangea macrophylla Using SSR Markers and a Pseudo-Testcross Strategy. International Hydrangea Conference.

Technical Abstract: We used a “two-way pseudo-testcross” mapping strategy in combination with simple sequence repeat (SSR) markers to construct a genetic map of Hydrangea macrophylla. Mapping populations were developed from reciprocal crosses between two divergent cultivars, “Bailmer” and “Veitchii”. “Bailmer”, which is sold as Endless Summer, is a remontant mophead. “Veitchii” is resistant to powdery mildew and has lacecap flowers. SSR markers have previously been used to estimate genetic diversity among hydrangea species and among Hydrangea macrophylla cultivars. Map construction was done using JoinMap 4.0 software, with a minimum LOD of 3.0 and a maximum recombination fraction of 0.4. Initial framework map was developed using more than 40 SSR loci as anchor markers. Backcross and sibmatings are available for future fine mapping with AFLP markers for greater marker saturation.