Potencial de la hibridación interespecífica para el mejoramiento de Paspalum grupo Dilatata

Grazing systems in Uruguay do not generally contemplate the inclusion of summer perennial grasses such as those of the Paspalum genus. The incorporation of this functional group of C4 species could contribute to greater biodiversity, as well as to the seasonal stability of production in order to take advantage of the resources available in the summer. Within this genus there are materials that have shown different advantages such as  long growing season, tolerance to early frost, and the occupation of niches that could be used by summer weeds of great importance such as Cynodon dactylon. However, they have some disadvantages such as low seed production and susceptibility to Claviceps paspali, which differ depending on the material to which we are referring. Based on the benefits that could mean including these species within the production systems, genetic improvement programs are justified, which have been approached with different strategies. In this matter, the objective of this study was to determine the potential of the interspecific hybridization method between two sexual materials of the Dilatata group, P. flavecesns and P. plurinerve, in order to find alternative ways to the use of apomictic materials, which entail the disadvantages specified above. The same crossing was previously carried out within the Faculty of Agronomy, where transgressive segregation was obtained for other characters of interest in earlier generations. High probabilities of obtaining transgressive segregating lines in more advanced generations were estimated, serving as a starting point for the present work. Biomass cuts were made beginning in the month of May, when all the plants in the population had reached reproductive status, with subsequent drying of the samples, ending with the separation of hardened sheets and sheaths to determine leaf weights and stem respectively. From a single cross, a great variability was obtained, within which the results showed transgressive segregating lines in the F6 generation at the level of the three characteristics studied. These lines may be agronomically evaluated with the aim of obtaining new cultivars in the long term. In addition, a wide range of promising lines was observed that, although they did not exceed the threshold of significance established by the test, could be of interest to take into account in future trials. This cross in particular is a sample of what the interspecific hybridization method is capable of generating, opening the possibility of continuing to study other crosses within the pool of sexual tetraploids that make up the Dilatata group.