Genetic linkage maps of Dendrobium moniliforme and D. officinale based on EST-SSR, SRAP, ISSR and RAPD markers

The genome organization of Dendrobium species remains largely unexplored. An F-1 family derived from the controlled interspecific hybridization between Dendrobium moniliforme and D. officinale were used to create genetic linkage maps of parental Dendrobiums using double pseudo-testcross strategy. A total of 422 markers, including 66 EST-SSR, 126 SRAP, 74 ISSR, and 156 RAPD markers, showed expected Mendelian segregation ratio and were used for genetic map construction. Genetic linkage groups with Kosambi genetic distances were constructed using a LOD score >= 4 and a recombination threshold of 0.4. The map of D. moniliforme was 1127.9 cM in total length with 165 marker loci distributed in 17 linkage groups: and the D. officinale map consisted of 19 genetic linkage groups with a total length of 1210.9 cM positioned by 169 marker loci. The genetic maps constructed in this study can serve as a reference linkage map of Dendrobium species for efficient studies of comparative genetics, genetic mapping of traits with economic interest, and marker-assisted selection in horticultural breeding. (C) 2012 Elsevier B.V. All rights reserved.