Genetic linkage map construction for kenaf using SRAP, ISSR and RAPD markers

Kenaf (Hibiscus cannabinus L.) is one of the most economically important crops for fibre production. Genetic maps have been developed in almost all the agricultural crops. However, genetic information for kenaf, especially, at the molecular level is limited. To better understand the genetic basis of kenaf for the improvement of production and to lay the foundation for molecular breeding efforts, a primary genetic linkage map was constructed using sequence-related amplified polymorphism (SRAP), inter-simple sequence repeat (ISSR) and randomly amplified polymorphic DNA (RAPD). Cultivar 'Alian kenaf' and 'Fuhong 992' were used as parents to construct an F-2 population consisting of 180 plants. We selected 494 SRAP, 60 ISSR, 120 RAPD and 300 two-primer RAPD mixture primers that amplified 396 polymorphic loci in total. At a logarithm of the odds (LOD) score threshold of 5.0 and at a maximum map distance of 25 cM, these 396 loci were used to construct the genetic linkage map with MAP-MAKER/EXP 3.0, a total of 307 loci were grouped into 26 linkage groups that spanned a total map length of around 4924.8 cM with a mean density of 16.04 cM per locus. These markers were distributed randomly in all linkage groups without any clustering. The construction of the kenaf genetic linkage map will be useful for further genetic studies including mapping both qualitative and quantitative traits, marker-assisted selection program, and comparative genomics analysis.