Aposory expressivity and parthenogenesis ability in diploid and autotetraploid genotypes of Paspalum rufum

DELGADO LUCIANA

Zavalla

Workshop; Advances in apomixis research; 2018

Facultad de Cs. Agrarias, UNR

Apomixis is a clonal reproduction pathway by seeds strongly linked to polyploidy. Its transference to commercial crops promises an opportunity to fix superior genotypes and hybrid combinations. Some diploid P. rufum genotypes contain aposporous embryo sacs and show apomixis ability. Moreover, hybridization and polyploidization induced higher apospory expressivity (%AES) in this species. The understandings of apomixis components (apospory and parthenogenesis) transmission in a diploid background and of the influence of polyploidy are key points for transferring the trait to diploid crops. Our objectives were to characterize the stability of %AES through time, analyze apospory inheritance in F2 populations, determine parthenogenesis ability of some individuals from the F1 population and to analyze the influence of polyploidy on reproductive behavior.F1 individuals with higher %AES (~35%) showed a decrease in the expression of the trait over time (~8%). On the other hand, F2 progenies showed similar %AES than their parental genotypes. Autopolyploid individuals produce similar %AES to their diploid counterpart, in contrast to previous results. Parthenogenesis was transmitted to some F1 diploids, but to all autotetraploids. Moreover, autotetraploids presented higher apomixis ability than their diploid counterpart.Results showed that %AES could be transmitted to advanced generations and is highly influenced by environmental conditions. Apomixis ability is increased by polyploidization, and seems not to be associated with the %AES or the apomixis ability of original diploid genotypes.