Development of Protocols for Regeneration and Transformation of Apomitic and Sexual Forms of Dallisgrass (Paspalum dilatatum Poir.)

Paspalum dilatatum (common name dallisgrass), a productive C4 grass native to South America, is an important pasture grass found throughout the temperate warm regions of the world. It is characterized by its tolerance to frost and water stress and a higher forage quality than other C4 forage grasses. P. dilatatum includes tetraploid (2n = 40), sexual, and pentaploid (2n = 50) apomictic forms, but is predominantly cultivated in an apomictic monoculture, which implies a high risk that biotic and abiotic stresses could seriously affect the grass productivity. The obtention of reproducible and efficient protocols of regeneration and transformation are valuable tools to obtain genetic modified grasses with improved agronomics traits. In this review, we present the current regeneration and transformation methods of both apomictic and sexual cultivars of P. dilatatum, discuss their strengths and limitations, and focus on the perspectives of genetic modification for producing new generation of forages. The advances in this area of research lead us to consider Paspalum dilatatum as a model species for the molecular improvement of C4 perennial forage species.

Automated summary

Paspalum dilatatum, a productive C4 grass, is widely distributed in temperate warm regions and known for its tolerance to frost and water stress. It has a higher forage quality than other C4 grasses. This species includes different forms, including tetraploid, sexual, and pentaploid apomictic forms. However, it is predominantly cultivated in an apomictic monoculture, which increases the risk of biotic and abiotic stresses affecting grass productivity. Aimed at improving agronomic traits, the development of reproducible and efficient regeneration and transformation protocols is crucial. This review discusses the current methods and limitations of regeneration and transformation in both apomictic and sexual cultivars of P. dilatatum, and explores the potential of genetic modification for creating improved forage varieties. The progress in this area positions P. dilatatum as a model species for molecular improvement of C4 perennial forage species.