Genetic transfer from several apomictic tetraploid paspalum species to an elite group of sexual plants
Fecha
2020Autor
Novo, Patricia Elda
Acuña, Carlos Alberto
Urbani, Mario Hugo
Galdeano, Florencia
Espinoza, Francisco
Quarin, Camilo Luis
Metadatos
Mostrar el registro completo del ítemResumen
Basic findings from classical genetic studies are available for exploiting apomixis
in the breeding of several forage grass genera. Most Paspalum species are multi-
ploid with a sexual diploid cytotype and conspecific apomictic polyploid (mainly
tetraploid) cytotypes. Experimental tetraploidized diploids reproduce sexually and,
when crossed with natural apomictic tetraploids, yield hybrid populations that
segregate for reproductive mode. Genetic studies indicated that apomixis is inherited
as a monogenic dominant factor. We recombined 50 selected sexual hybrids obtained
from crosses between a tetraploidized sexual genotype of P. plicatulum and 9 natural
apomictic tetraploid accessions of 6 species of the Plicatula group. A synthetic
sexual tetraploid population (SSTP) of 600 individuals from mixed seed of the 50
intercrossed hybrids was space-planted in the field. Based on evaluations of plant
vigor, seed set, ergot tolerance, regrowth after flowering, and cold tolerance, 31
plants were selected. Crosses between most selected plants and two testers, which
belonged to P. guenoarum, were performed, and the generated progeny was planted
into the field following a randomized block design with 3 replications. The progeny
test was evaluated for seed fertility, biomass yield, and cold tolerance. This procedure
allowed selection of 10 elite plants from the SSTP. These plants should contain
genes recombined from six apomictic species, without the genetic determinants for
apomixis. They may be polycrossed to generate an improved sexual population, or
crossed with other apomictic genotypes to obtain improved apomictic hybrids.
Colecciones
- Artículos de revista [476]