Advances in the Breeding of Paspalum Notatum towards a New Forage Cultivar

ACUÑA CARLOS A.; ZILLI, ALEX L.; BRUGNOLI, ELSA A.; MARCÓN, FLORENCIA

Workshop; 7th Series of Seminars on Advances in Apomixis Research; 2020

There is a need for developing forage cultivars for subtropical areas, which combine warm summers with cold winters, and marked variation in photoperiod. Paspalum notatum is an apomictic grass adapted to these transitional climate zones. The objective was to describe the advances of the Paspalum notatum breeding program in Argentina. Crosses were made between a few sexual clones and several apomictic ecotypes collected throughout the New World. Segregation for mode of reproduction varied between 1:1 to 1:7.4 between apomictic and sexual within families, with a mean of 1:3.2. A high variation was observed for apomixis expressivity within the apomictic progeny, with most hybrids exhibiting very low (less than 10% of the ovules bearing aposporous embryo sacs) or high expressivity (more than 70%). Only the highly apomictic hybrids were evaluated in the field as spaced plants for two years and sward plots for three years, especially considering frost tolerance, and growth during the cool season. Currently, five selected hybrids are being evaluated in three locations in northeastern, and one in central Argentina. A grazing trial is also being conducted to determine the grazing tolerance of these 5 hybrids. The genetic stability across cropping cycles will also be determine using molecular markers. A superior highly apomictic genotype is expected to be selected in two years.