Plant & Animal Genome IX Conference

Workshop: Apomixis
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EMBRYOLOGICAL AND MOLECULAR STUDIES OF APOMIXIS IN POA PRATENSIS

Institute of Plant Genetics and Crop Plant Research, Corrensstr. 3, D-06466 Gatersleben, Germany

Harnessing apomictic seed formation is considered to be one of the most favourable goals of plant breeding and production. The aposporous pseudogamous grass Poa pratensis has been used for genetic and molecular studies of apomictic processes. Based on cytoembryological studies five obligate sexual genotypes with various genetic background have been generated. Intraspecific crosses demonstrate the dominance of apomixis over sexuality and show the homozygous status of sexuals and the heteozygous status of apomicts at the corresponding loci. The flow cytometric seed screen (FCSS) provides the possibility to reconstruct the pathway of seed formation from mature seeds. The method allows the dissection of the apomictic process into the two components apomeisosis and parthenogenesis and led to the selection of genotypes exhibiting either apomeiosis or parthenogenesis separately. An initial molecular approach is based on five purely sexual and eight apomictic genotypes of Poa pratensis. SMART amplified cDNA from gynoecia at the developmental stage of aposporous initial cell formation has been used for subtractive hybridisation approaches and candidate sequences have been isolated.