Genome mapping of tetraploid cotton : towards a saturated and unified map

DNA-based genetic maps have been produced in nearly all major crop species, thus facilitating the analysis of genome structure and evolution, and improving efficiency and accuracy of breeding. We have developed at Cirad/France a combined and saturated RFLP-AFLP-SSR genetic map of tetraplaid cotton from the analysis of the 1st and 2nd backcross generations of an interspecific Gossypium hirsutum (cv 'Guazuncho 2') x G. barbadense (cv 'VH8') cross. The BC1 and BC2 maps were independently constructed from the analysis of 75 arid 200 individual plants respectively. As a recent development, a microsatelliteenriched library had been developed and 418 new microsatellite primers defined. One hundred and sixty one microsatellites showing at least one polymorphism between Guazuncho 2 and VH8 had been screened on the BC1 population, and 785 new loci were added on the BC 7 map. Having 360 loci in common between the BC1 (1107 loci in total) and tile BC2 (513 loci in total) map proved helpful to confirm loci orders along linkage groups, and allowed small linkage groups to be joined to larger ones. A total of 138 additional loci, mainly AFLP, of the BC2 map were added to the skeleton BC? map. Finally, after merging the BC1 and BC2 mapping data, the Guazuncho 2 x VH8 map now comprises 1260 loci divided mainly between AFLPs (40%), SSRs (34%) and RFLPs (15%). The 26 linkage groups span altogether over 5400 cM. Details of the Guazuncho 2 x VH8 map are commented. An important number of microsatellite and RFLP markers used in the present study are common with other published genetic maps also derived from interspecific G, hirsutum x G. barbadense populations. As a preliminary step towards an integration of the different maps, we used a "neighbor approach" applied to 4 of tth 26 chromosomes by aligning these maps using these bridge loci. An overall agreement in locus order and distances has been observed. Integration of genetic maps into a denser consensus unified map of tetraploid cotton and future feasibility of genetic arid physical maps integration are discussed.

Bibliographic Details

Main Authors:	Lacape, Jean-Marc, Nguyen, Trung-Bieu, Courtois, Brigitte, Bojinov, B., Hau, Bernard
Format:	conference_item biblioteca
Language:	eng
Published:	ARC-IIC
Subjects:	F30 - Génétique et amélioration des plantes, Gossypium hirsutum, Gossypium barbadense, tétraploïdie, carte génétique, http://aims.fao.org/aos/agrovoc/c_3339, http://aims.fao.org/aos/agrovoc/c_3337, http://aims.fao.org/aos/agrovoc/c_7690, http://aims.fao.org/aos/agrovoc/c_24002,
Online Access:	http://agritrop.cirad.fr/520541/ http://agritrop.cirad.fr/520541/1/ID520541.pdf
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