ARS | Publication request: MODIFIED DIALLEL ANALYSIS OF FIRST YEAR HEIGHT OF CRAPE MYRTLE HYBRIDS

Submitted to: Southern Nursery Association Research Conference
Publication Type: Proceedings/Symposium
Publication Acceptance Date: August 10, 2004
Publication Date: December 10, 2004
Citation: Pounders Jr, C.T., Cheatham, C.L. 2004. Modified diallel analysis of first year height of crape myrtle hybrids. Southern Nursery Association Research Conference pg 572-574.

Interpretive Summary: Ornamental producers and consumers are interested in obtaining pest resistant crape myrtle clones that grow quickly to tree form in a range of flower colors, such as deep reds and purples. Techniques such as modified diallel mating designs assist in selection of parents for hybridization that produce progeny with the desired early height growth rates. Information on parental combining ability for growth rate can be combined with other studies on the inheritance of flower color and pest resistance to target parental combinations that have the highest potential to produce clones with a selected set of traits. 'Osage' and 'Arapaho' were the disease resistant parents that produced the greatest first year average height growth when crossed to the colorful parents of this study. 'Catawba' and 'Whit IV' were the colorful parents which produced seedlings with the greatest height growth when crossed to the disease resistant parents.

Technical Abstract: Controlled pollinations were made in 2002 between the powdery mildew resistant USDA releases 'Arapaho', 'Osage', 'Tonto', 'Tuscarora' and 'Tuskegee' and the colorful purple or red clones 'Catawba', 'Velma's Royal Delight', ' Whit II' and 'Whit IV'. First year height was determined to be a highly heritabile trait when calculated for either individuals (hI 2 = 0.78) or families (hF2 = 0.64). Fast progress is expected in selecting clones for rapid early height growth either on an individual or family basis when crossing disease resistant parents with more colorful crape myrtle germplasm such as the clones used in this study. 'Osage' and 'Arapaho' were the disease resistant parents that produced the greatest first year average height growth when crossed to the colorful parents of this study. 'Catawba' and 'Whit IV' were the colorful parents which produced seedlings with the greatest height growth when crossed to the disease resistant parents. The families with greatest average first year height growth were 'Osage' crossed to 'Catawba', 'Osage' crossed to 'Whit IV' and 'Osage' crossed to 'Whit II'.