A Parthenogenesis Gene Candidate and Evidence for Segmental Allopolyploidy in Apomictic Brachiaria decumbens

• DOI: 10.1534/genetics.116.190314
• Publication Date: 2016-05-23T07:50:43Z
• Authors: Margaret Worthington; Christopher Heffe...; Diana Bernal; Constanza Quintero; Yeny Patricia Zapata; Juan Guillermo Perez; Jose De Vega; John Miles; Stephen Dellaporta; Joe Tohme
• Keywords: Apomixis; Brachiaria; Pennisetum; Triticeae

Apomixis, asexual reproduction through seed, enables breeders to identify and faithfully propagate superior heterozygous genotypes by seed without the disadvantages of vegetative propagation or expense complexity hybrid production. The availability new tools such as genotyping sequencing bioinformatics pipelines for species lacking reference genomes now makes construction dense maps possible in apomictic species, despite complications including polyploidy, multisomic inheritance, self-incompatibility, high levels heterozygosity. In this study, we developed saturated linkage maternal paternal an interspecific Brachiaria ruziziensis (R. Germ. C. M. Evrard) × B. decumbens Stapf. F1 mapping population order markers linked apomixis. High-resolution molecular karyotyping comparative genomics with Setaria italica (L.) P. Beauv provided conclusive evidence segmental allopolyploidy decumbens, strong preferential pairing homologs across genome segregation relatively more common chromosome 8. apospory-specific genomic region (ASGR) was mapped a reduced recombination on 5. Pennisetum squamulatum R.Br. PsASGR-BABY BOOM-like (psASGR-BBML)-specific primer pair p779/p780 perfect ASGR diagnostic reproductive mode diversity panel known sexual apomict (Trin.) Griseb. maximum Jacq. germplasm accessions cultivars. These findings indicate that ASGR-BBML gene sequences are highly conserved Paniceae add further support postulation candidate genes function parthenogenesis.