Comparison of Apospory-Specific Genomic Region (ASGR)-Carrier Chromosome Between Guineagrass (Panicum maximum) and Pennisetum species

Apomixis is a phenomenon that produces clonal progeny through seed reproduction. Apomixis can maintain heterosis in hybrid progeny and accelerate hybrid breeding; therefore, apomixis can be a tremendous tool for plant breeding. Apospory is a mode of apomixis that is considered to be controlled by a single specific chromosome, the Apospory-Specific Genomic Region (ASGR)-carrier chromosome. The ASGR-carrier chromosome was discovered in aposporous Pennisetum and Cenchrus species, but a portion of it (the ASGR) is absent from related sexual species. The ASGR-carrier chromosome showed varied morphology among the species; however, the ASGR maintains some common features among the species.

Guineagrass (Panicum maximum) has sexual and aposporous strains. The ASGR-carrier chromosome was discovered only in the aposporous strains. In this study, we aimed to compare the ASGR between P. maximum and Pennisetum species by molecular markers and fluorescence in situ hybridization (FISH). The results indicated that the ASGR was conserved between P. maximum and Pennisetum species.