Construction of a genetic linkage map in Ilex paraguariensis (yerba mate)

STEIN J; LUNA C; ESPASANDIN F; SARTOR M; SAUCEDO ME; ESPINOZA F; ORTIZ JPA; SANBERRO P; PESSINO S

Rosario

Congreso; XV Congreso Latinoamericano de Genetica; 2012

Sociedad Agentina de Genetica

The use of molecular technologies applied to the breeding of Ilex paraguariensis might accelerate the generation of superior varieties. The objectives of this project were: 1) characterize the I. paraguariensis genome by the use of molecular markers and 2) generate a group of anchored markers with transference potential, covering the whole genome on a systematic approach. Crossing of a female genotype (SI-67) to a highly divergent male one (SI-49) generated an abundant seed set. Immature embryos were rescued and cultivated in vitro to produce a pseudo-tescross segregating progeny of 700 individuals. After assaying several techniques, a protocol based on a combination of CTAB and glucose was selected to extract genomic DNA from a 60-plants subpopulation. Currently, we are starting map construction. Up to date, 14 RAPD decamers and 4 AFLP primer combinations were used to produce 22 female markers, 23 male markers and 10 allelic bridges. Female, male and bridge data were loaded into binary matrixes and processed with the JoinMap 3 program. Linkage groups were constructed using LOD scores between 1.0-6.0 and rmax = 0.40. In the female map, 16 markers resulted linked in 5 different groups. In the male map, 24 markers assembled in 7 different groups. Once the groups were defined, markers were ordered using the Kosambi mapping function at LOD value ¡Ý 0.5. Four and five linkage groups were ordered from the female and male maps, respectively. Ten markers were selected to start the construction of a set of RFLP clones evenly distributed onto the yerba mate genome.