A rise of ploidy level induces the expression of apomixis in Paspalum notatum.

QUARIN, C. L.; FRANCISCO ESPINOZA; MARTÍNEZ, E. J.; PESSINO, S. C.; BOVO, O. A.

PLANT REPRODUCTION

SPRINGER

Año: 2001 vol. 13 p. 243 - 249

2194-7953

The common races of bahiagrass, Paspalum notatum, are tetraploid (2n=4x=40) and reproduce by aposporous apomixis. Paspalum notatum var. saurae is the corresponding diploid (2n=2x=20) sexual race that outbreeds due to self-incompatibility. Chromosome doubling was induced by colchicine treatments in three individual plants from a natural diploid population. Embryologicalstudies demonstrated that one of the induced autotetraploid plants reproduced sexually. The other two autotetraploids were facultative apomicts. These resultsindicate that an unexpressed gene(s) for apomixis exists at the diploid level. The expression of the trait is ploidydependent. The ploidy dependency may act either on the locus controlling apomixis through some transcription factors or via a secondary locus which requires a higher allele dosage to affect the expression of the main locus.