The 2012 ASHS Annual Conference

The domestication and selective breeding of peach has increased fruit size, fruit blush, firmness, palatability, and decreased acidity and bitterness compound levels relative to wild peaches.  However, there has not been a concomitant change in tree structure and there is little difference between a tree of a wild peach such as P. davidiana and a tree of ‘Redhaven’ peach.  Changes in labor regulations and improvements in wages have increased the interest in mechanized pruning and fruit thinning to reduce production costs.  However, the complicated architecture of current peach varieties does not lend itself for mechanized fruit production.  As part of our peach breeding effort, we are trying to get a better understanding of peach tree architecture.  For this purpose we have made interspecific hybrids between peach and closely related species, generated segregating populations, and performed QTL analysis for branching traits.  Candidate gene analysis of genes involved in meristem formation and extension growth from peach, almond and kansu wild peach was performed.  Gene specific haplotypes were generated for representatives of the three species and the data used to design markers for mapping and QTL analysis. Data will be presented on the mapping and QTL analysis of branching and node development in peach x (peach x almond) and peach x (peach x kansu peach) backcross populations.