Development of Reference Karyotypes for Longleaf and Shortleaf Pines using Fluorescence in situ Hybridization

The Southern Institute of Forest Genetics is developing reference karyotypes for each of the major southern U. S. pine species— loblolly (Pinus taeda), slash (P. elliottii var. elliottii), shortleaf (P. echinata) and longleaf (P. palustris)— using 18S-28S rDNA, 5S rDNA, and Arabidopsis-type telomere repeat (ATR) sequence probes and AT-rich banding. Reference karyotypes for loblolly and slash pines have been completed. Preliminary results for the rDNA genes show that both shortleaf and longleaf pines contain seven major intercalary 18S-28S rDNA sites. Shortleaf pine showed as many as three major and six medium-to-minor centromeric 18S-28S rDNA sites, while longleaf pine showed one major and six medium-to-minor centromeric 18S-28S rDNA sites. Both species showed one major and one minor site for 5S rDNA. There are as many as five ATR sites with different degrees of signal intensities located near the centromeres of each chromosome in both longleaf and shortleaf pine. In addition, strong AT-rich bands were found to flank the centromeres of most chromosomes in both species. Complete karyotypes for shortleaf and longleaf pines are being developed for comparison to each other and to the existing loblolly and slash pine karyotypes.

Download this file:

Download this file

Details

Author(s): M. N. Islam-Faridi, M. Abdul Majid, H. Banda, C. Dana Nelson

Publication: Tree Improvement and Genetics - Southern Forest Tree Improvement Conference - 2007