title: SSR and EST-SSR-based genetic linkage map of cassava (Manihot esculenta Crantz).
abstract: Simple sequence repeat (SSR) markers provide a powerful tool for genetic linkage map construction that can be applied for identification of quantitative trait loci (QTL). In this study, a total of 640 new SSR markers were developed from an enriched genomic DNA library of the cassava variety 'Huay Bong 60' and 1,500 novel expressed sequence tag-simple sequence repeat (EST-SSR) loci were developed from the Genbank database. To construct a genetic linkage map of cassava, a 100 F(1) line mapping population was developed from the cross Huay Bong 60 by 'Hanatee'. Polymorphism screening between the parental lines revealed that 199 SSRs and 168 EST-SSRs were identified as novel polymorphic markers. Combining with previously developed SSRs, we report a linkage map consisted of 510 markers encompassing 1,420.3 cM, distributed on 23 linkage groups with a mean distance between markers of 4.54 cM. Comparison analysis of the SSR order on the cassava linkage map and the cassava genome sequences allowed us to locate 284 scaffolds on the genetic map. Although the number of linkage groups reported here revealed that this F(1) genetic linkage map is not yet a saturated map, it encompassed around 88% of the cassava genome indicating that the map was almost complete. Therefore, sufficient markers now exist to encompass most of the genomes and efficiently map traits in cassava.
authors.affiliation: Institute of Molecular Biosciences, Mahidol University, Nakhonpathom, Thailand.
authors.forename: Supajit
authors.initials: S
authors.lastname: Sraphet
authors.forename: Athipong
authors.initials: A
authors.lastname: Boonchanawiwat
authors.forename: Thanwanit
authors.initials: T
authors.lastname: Thanyasiriwat
authors.forename: Opas
authors.initials: O
authors.lastname: Boonseng
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Shigemi
authors.initials: S
authors.lastname: Sasamoto
authors.forename: Kenta
authors.initials: K
authors.lastname: Shirasawa
authors.forename: Sachiko
authors.initials: S
authors.lastname: Isobe
authors.forename: David A
authors.initials: DA
authors.lastname: Lightfoot
authors.forename: Sithichoke
authors.initials: S
authors.lastname: Tangphatsornruang
authors.forename: Kanokporn
authors.initials: K
authors.lastname: Triwitayakorn
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping / Q000379:methods*; D032461:Chromosomes, Plant; D030541:Databases, Genetic; D020224:Expressed Sequence Tags; D008040:Genetic Linkage; D005819:Genetic Markers; D002365:Manihot / Q000235:genetics*; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D040641:Quantitative Trait Loci
chemical_list: D005819:Genetic Markers