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

QUARIN, CAMILO L.; ESPINOZA, FRANCISCO; MARTÍNEZ, ERIC J.; PESSINO, SILVINA C.; BOVO, OSCAR A.

SEXUAL PLANT REPRODUCTION

Springer

Lugar: Heidelberg, Germany; Año: 2001 vol. 13 p. 243 - 249

0934-0882

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB;} @page Section1 {size:595.3pt 841.9pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> 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 outbreed due to self-incompatibility. Chromosome doubling was induced by colchicine treatments in three individual plants from a natural diploid population. Embryological studies demonstrated that one of the induced autotetraploid plant reproduced sexually. The other two autotetraploids reproduced by means of facultative apomixis. These results indicate that unexpressed gene/s for apomixis exist at the diploid level. The expression of the trait is ploidy-dependent. The ploidy dependency may either act directly on the locus controlling apomixis or via a secondary locus, which requires a higher allele dosage to affect the expression of the main locus.