Recurrent phenotypic selection and recurrent selection based on combining ability in tetraploid bahiagrass

MARCÓN, FLORENCIA; MARTÍNEZ, ERIC J.; ZILLI, ALEX L.; RODRÍGUEZ, GUSTAVO R.; BRUGNOLI, ELSA A.; ACUÑA, CARLOS A.

CROP SCIENCE

CROP SCIENCE SOC AMER

Año: 2020 vol. 60 p. 1386 - 1397

0011-183X

Paspalum notatum Flüggé is an apomictic grass used for forage and turf. The recent generation of a sexual synthetic tetraploid population of the species provides the unique advantage to exploit heterosis by accumulating favorable alleles through recurrent selection cycles. The objective was to evaluate recurrent phenotypic selection (RPS) and recurrent selection based on combining ability (RSCA) as breeding methods. The best sexual genotypes in terms of warm-season growth from a sexual synthetic tetraploid population were selected by RPS and RSCA. The selected genotypes were polycrossed and two new sexual populations were created, which were crossed with superior apomictic genotypes. Both methods allowed obtaining families that were evaluated for summer, fall, and spring growth. Breeding values and heterosis were also calculated. Summer growth for RPS families was greater than RSCA families (33.1 g plant-1 and 29.08 g plant-1, respectively), however, for fall, spring and accumulated growth were similar. The breeding value for RPS sexual parents was greater than RSCA sexual parents for summer growth, whereas for fall and spring growth were similar. A greater level of families with heterosis (80%) was observed for RPS than RSCA (30%) for summer growth, while for fall and spring growth were similar. These results are indicating that both breeding methods were successful in improving tetraploid P. notatum. They increased the mean value of the progenies and produced families superior for forage yield by accumulating favorable alleles.