Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 1.36

CLONING OF CANDIDATE GENES FOR APOMIXIS IN KENTUCKY BLUEGRASS (P. PRATENSIS L.)

E. ALBERTINI, G. MARCONI, M. FALCINELLI

Dipartimento di Biologia Vegetale e Biotecnologie Agroambientali, University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy

apomixis, cDNA-AFLP, differential display, Poa pratensis

Poa pratensis L., one of the most important forage and turf grasses in temperate climates, has a versatile and dynamic mode of reproduction that ranges naturally from nearly obligate apomixis to complete sexuality. In this species apomixis is functionally the result of two processes: apospory and parthenogenesis. Despite extensive efforts aimed at understanding the inheritance of apomixis, the identity of the gene/s controlling the reproductive process is still obscure as well as it is not known whether the combination of apomictic features (apospory with parthenogenesis) derives from the expression of one single gene or a few linked genes. Our research project deals with the elucidation of the genetic control of apomixis and with the cloning of candidate genes for both apomixis as a whole and its elements (i.e. apospory and parthenogenesis). A gene expression study was carried out by using the cDNA-AFLP technique in order to select and isolate differentially expressed mRNAs for apospory and parthenogenesis. Within an F1 population of P. pratensis segregating for the mode of reproduction an highly apomictic (aposporic and parthenogenetic), a completely sexual (non-aposporic and non-parthenogenetic), and also a recombinant (aposporic and non-parthenogenetic) genotypes were selected on the basis of auxin test and cytohistological investigations and used for mRNA profiling by AFLP markers. The approach enabled us to select 172 mRNAs either apomictic- or sexual-specific and to detect transcriptional changes potentially related to apospory and parthenogenesis. About 30% of clones showed no similarity with genes of interest whereas the other 70% showed similarity with genes involved with meiotic or embryo development pathways. Interestingly a group of genes differentially expressed between apomictic and sexual genotypes showed an high similarity with a group of genes tightly linked in Arabidopsis thaliana.