Plant, Animal & Microbe Genomes X Conference

January 12-16, 2002
Town & Country Convention Center
San Diego, CA

Workshop: Apomixis
            

THE GENETICS OF AUTONOMOUS APOMIXIS IN DANDELIONS

¹ Netherlands Institute of Ecology (NIOO-CTO), PO Box 40, 6666 ZG Heteren, The Netherlands

Apomixis in the common dandelion (Taraxacum officinale ) comprises three elements: (i) First Division Restitution meiosis (diplospory), (ii) embryo parthenogenesis and (iii) autonomous endosperm development. Crosses between diploid sexuals (2n=16) and triploid apomicts (2n=24) indicate that these elements can recombine and thus must be regulated by different genes. Diplospory alone is inherited as a dominant monogenic trait, that is located on one of the NOR-chromosomes. Markers that are linked to diplospory can be transmitted via diploid but not via haploid pollen grains. This suggests that one or more recessive lethal factors are linked to diplospory. Moreover, non-transmission via haploid pollen forms an explanation for the absence of apomixis in diploids, as these are produced from haploid pollen grains. In order to investigate the structure of the diplospory chromosomal region, we recently started an AFLP fine mapping project. The first results of this will be presented.