Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2003
Publication Date: 7/10/2003
Citation: Wu, X., S. R. Larson, Z. Hu, A. Palazzo, T. A. Jones, R. R.-C. Wang, K. B. Jensen, and N. J. Chatterton. Molecular genetic linkage maps for allotetraploid Leymus wildryes (Gramineae: Triticeae). Genome 46:627-646. 2003. Interpretive Summary: Genetic maps were constructed for two hybrid populations derived from two North American perennial grasses, Leymus triticoides and L. cinereus. The genetic map for one population, comprised of 164-siblings, includes 1102 DNA markers 14 linkage groups. The genetic map for another population, comprised of 170 siblings, contains 1032 DNA markers in 14 linkage groups. Comparing populations, the genetic map order of 511 common DNA markers was virtually identical among the 14 linkage groups, which evidently correspond to the 14 chromosomes of allotetraploid Leymus wildryes. These plant populations and corresponding genetic maps will be used to identify chromosomal regions genetically assocated with sod-forming grass rhizomes, proliferation of rhizomatous perennial grass weeds, seed dormancy, and extreme salinity tolerance in long-lived grasses of the Great Basin region.
Technical Abstract: Molecular genetic maps were constructed for two full-sib populations, TTC1 and TTC2, derived from two Leymus triticoides x L. cinereus hybrids and one common L. triticoides tester. Populations were screened with 21 EcoRI/MseI and 17 PstI//MseI AFLP primer combinations plus 36 anchored simple-sequence repeat (SSR) or sequence-tagged site (STS) primer pairs. The 164-sib TTC1 map includes 1069 AFLP and 33 anchor markers in 14 linkage groups spanning 1940 cM. The 170-sib TTC2 map contains 1002 AFLP and 30 anchor markers in 14 linkage groups spanning 1966 cM. Some 488 AFLP bridge loci and 23 anchor markers were mapped in both populations, with virtually identical linear orders among the 14 groups. Thus, 1583 AFLP and 40 anchor loci were mapped into 14 linkage groups that evidently correspond to the 14 chromosomes of allotetraploid Leymus (2n=4x=28). Synteny of two or more anchor markers corresponding to each of the seven homoeologous Triticeae chromosomes was maintained among 12 of the 14 Leymus linkage groups. However, one linkage group contained several anchor markers from homoeologous groups 7 and one anchor marker from homoeologous group 6. One set of genome-specific DNA sequences located on Leymus homoeologous groups 4 and 5 were nearly identical to Psathyrostachys juncea. An orthologous DNA sequence located on the other Leymus homoeologous group 5 showed high similarity to Psathyrostachys fragilis.