Resumen de Differentiation of apomictic and sexual genotypes of Brachiaria spp., using molecularmarkers

Jaime Poblete-Vargas, Ernestina Valadez Moctezuma, Gabino García de los Santos, Juan Carlos Martínez González, Armando Peralta-Martínez

• español

  RESUMEN. Algunas especies de Brachiaria se cultivan en los trópicos por su alta productividad y resistencia a sequía; sus híbridos apomicticos, son de interés por la casi nula segregación y fijación del vigor híbrido. En este trabajo se utilizaron marcadores Amplified Fragment Length Polymorphism (AFLPs) y Cleaved Amplified Polymorphic Sequences (CAPS) para diferenciar progenitores apomicticos tetraploides y sexuales diploides de Brachiaria y su progenie. El polimorfismo detectado con AFLPs fue del 91.3% y con CAPS del 79.7%. Los fenogramas diferenciaron a cada genotipo y agrupación de progenitores con la progenie por su grado de parentesco genético. Los AFLPs no separaron a los genotipos apomicticos de los sexuales, pero los CAPS si lo lograron mediante el marcador C15-8; algunos genotipos apomicticos de la progenie, lo heredaron de la madre sexual B. ruziziensis, lo que puede estar relacionado con algún carácter segregante de la línea progenitora.

• English

  ABSTRACT. Some species of Brachiaria are cultivated in the tropics because of their high productivity and drought resistance; their apomictic hybrids are of interest because of the almost nuil segregation and fixation of the hybrid vigor in seeds. In this research, Amplified Fragment Length Polymorphism (AFLP) and Cleaved Amplified Polymorphic Sequence (CAPS) markers were used to differentiate apomictic tetraploid and sexual diploid Brachiaria parents and their progeny. Polymorphism detected with AFLP was 91.3% and with CAPS 79.7%. Phenograms differentiated each genotype and the clustering of parents and their progeny was by their degree of genetic relatedness. AFLP did not separate the apomictic genotypes from the sexual ones, but CAPS markers did so through the C15-8 marker. Some apomictic genotypes of the progeny inherited it from their B. ruziziensis sexual mother, which may be related to some segregating character of the parental line.