ARS | Publication request: GENETIC INTERACTIONS OF PILLAR, COMPACT, AND DWARF PEACH TREE GENOTYPES

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 11, 2001
Publication Date: N/A

Interpretive Summary: Peach trees are large and spreading. They require intensive and expensive pruning to maintain their allotted space in the orchard or home garden. It is estimated that 30% of the cost of peach production can be attributed to pruning. Through breeding we have developed peach trees with a columnar shape. By cross breeding these columnar trees with dwarf, compact, and other naturally-occurring peach tree growth habits we have developed a wid range of peach tree growth habits that may be useful in commercial high- density production systems and/or for the home garden. In this report we describe the inheritance of growth habit in peach. Understanding the inheritance of these growth habits will allow us to more efficiently and more effectively breed new varieties of peaches with novel, useful tree forms and high quality fruit for commerical growers and home gardeners.

Technical Abstract: The pillar (PI) habit (brbr) examined in this study was inherited as a monogenic trait expressing incomplete dominance. The heterozygous Brbr derived from in crosses between standard ST and PI genotypes was recognized as an upright (UP) tree with narrower branch angles than ST trees but wider than PI trees. The combination of brbr and brachytic dwarf (DW) (dwdw) produced dwarf-pillar (DWPI) trees. The effects of the heterozygous Brbr i combination with dw and/or compact (CT)(Ct) could not be recognized by vis- ual observation. Compact pillar (CTPI) trees resulted from the expression of Ct_ brbr. These trees were distinguished from globe-shaped (GL) trees (Ct_Brbr) by the more upright growth habit of the CTPI trees. This genetic study highlights the genetic "plasticity" of tree growth habit in peach. The investigation of novel growth habits extends our concept of the peach tree. Some growth habits such as PI may have commercial potential for high density peach production systems. Others, such as PIDW and CTPI, may have potential as ornamentals.