Plant & Animal Genome VI Conference

P94

SEX-LINKED AFLP MARKERS IN Asparagus officinalis L.

Institute of Crop Science and Plant Breeding, Christian-Albrechts-University of Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany

Asparagus officinalis L. is a dioecious plant. The female has the constitution XX while the male XY. However, other types exist such as supermales (YY) and the andromonoecious plants (XY), which can self occasionally. The gene that determines sex has been located on a pair of homomorphic pair of chromosome L5. For asparagus cultivation, male plants are desired due to higher yield. The supermales are important in producing all male asparagus varieties. On a F₂ population from a selfed andromonoecious plant (1XX:2XY:1YY), nine AFLP markers linked to the sex locus have been identified by AFLP technique and bulked segregant analysis. Further screening of two F₁ populations with the nine markers gave three very tightly linked markers. These markers did not give recombinants in the three different populations and mapped 0.5, 0.7 and 1 cM to the sex locus in the composite map on the L5 chromosome.Codominant scoring of the markers in the F₂ population could distinguish the XX, XY and YY asparagus plants. Southern hybridization of cloned AFLP markers showed low copy to middle repetitive signals. The marker E41M50, which did not give any recombinants in the screened populations, detected RFLPs between female and male plants.