Plant Genome II Conference
Town & Country Conference Center, San Diego, CA, January, 1994.
PG-II: MARKER-AIDED BACKCROSS BREEDING FOR EARLY HEIGHT GROWTH IN
LONGLEAF PINE
MARKER-AIDED BACKCROSS BREEDING FOR EARLY HEIGHT GROWTH IN
LONGLEAF PINE
Kubisiak, T.L. 1, Nelson, C.D. 2, W.L. Nance 2, and M. Stine 1.
1 Louisiana State University Agricultural Center, School of
Forestry, Wildlife, and Fisheries, Louisiana State University,
Baton Rouge, LA 70803, 2 U.S.D.A. Forest Service, Southem Forest
Experiment Station, Southern Institute of Forest Genetics,
Gulfport, MS 39505
Despite many desirable qualities, longleaf pine (Pinus
palustris Mill.) has found limited use in artificial regeneration
programs because of its often poor survival rate and extended
phase of reduced height growth referred to as the grass stage.
Most longleaf pine improvement programs have focused on brown-
spot needle blight resistance, and early height growth (EHG).
Compared to loblolly pine or slash pine, efforts to improve
longleaf pine have been limited. Interspecific hybrids show
promise for addressing the problem of delayed EHG in longleaf
pine. Intermediate height growth has been observed in different
longleaf pine x slash pine or longleaf pine x loblolly pine
families. It has been estimated that as few as 10 loci may be
influencing EHG. The fact that a source of genes regulating EHG
have been identified, and that a limited number of loci appear to
be influencing EHG, suggests that an interspecific backcross
breeding approach might be successfully employed to control the
grass stage in longleaf pine. Automation of the RAPD technique
has now made it possible to quickly identify large numbers of
markers. By employing molecular markers in two backcross
populations, one with longleaf pine as the recurrent parent and
one with slash pine as the recurrent parent, we hope to obtain a
more complete understanding of the genetic control and
inheritance of EHG. Our plan is to use backcross families
produced from the same hybrid parent. This will provide the
opportunity to study the segregation of EHG alleles (both
positive effect EHG alleles from slash pine, and negative effect
EHG alleles from longleaf pine) in populations with comparable
genetic backgrounds.
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