Synthesis of new plant material and development of molecular tools for improving species of the Plicatula group of Paspalum

NOVO P; AGUILERA P; SARTOR M; GALDEANO F; WEIHMÜLLER E; PESSINO SC; QUARIN CL; ORTIZ JPA; ESPINOZA F

Foz de Iguazú

Congreso; 11th International Congress Plant Molecular Biology 2015 (IPMB 2015); 2015

International Plant Molecular Biology

The Plicatula group of the genus Paspalum includes approximately 30 species. Most of them have forage potential for the tropical and subtropical regions of South America. Typically, species form multiploid complexes with diploid (2n=2x=20) sexual cytotypes and tetraploid (2n=4x=40) apomictic counterparts. The objective of this work was to develop novel sexual genotypes and molecular tools for breeding and fundamental analysis of apomixis in the group. After chromosome doubling of a diploid plant of P. plicatulum a 100 % sexual autotetraploid individual (4PT) was obtained. Clones of 4PT were crossed with different tetraploid apomictic genotypes to generate segregating populations. Among the F1 progenies, sexual hybrids were selected using the flow cytometric seed screen method. Then, phenotypic and genotypic characterization was used for developing a completely sexual synthetic population with a wide genetic base. On the other hand, one interspecific hybrid F1 progeny of 211 plants segregating for reproductive mode was generated by crossing P. plicatulum (4PT) x P. guenoarum (4xA). Marker segregation analysis of F1 showed that both species displayed tetrasomic inheritance. This population was used for the construction a core genetic linkage map of the apomictic parent base on AFLP markers. The genetic map contained 127 markers distributed on 23 linkage groups, which spanned on 1,393 cM. Two markers linked in coupling at both sides of apomixis locus (at 4 and 7 cM) were detected. Our results provided novel genotypes and molecular markers for breeding species of the group and tagging the apomixis determinants.