A model for the genetic modification of wild plant species

Low dispersal and ploidy differences in a grass maintain photosynthetic diversity despite gene flow and habitat overlap

“…Independent of the mechanism, both pre‐ and post‐zygotic negative interactions would decrease the fitness of the photosynthetic type that is at low frequency in a mixed population and therefore has a high probability to reproduce with the alternative photosynthetic type (Lewis, 1961; Ray et al, 1979; Toll & Willis, 2018). In the absence of ecological differentiation, the photosynthetic type that first colonized and became abundant in a given area would therefore retain an advantage due to its higher frequency.…”

“…In the absence of ecological differentiation, the photosynthetic type that first colonized and became abundant in a given area would therefore retain an advantage due to its higher frequency. While some introgression might still occur, newly arrived individuals would gradually disappear from each locality (Nishida et al, 2020; Ray et al, 1979; Templeton, 1981; Whitton et al, 2017), leading to the spatial sorting of photosynthetic types (Nishida et al, 2020). In the case of A. semialata , the low connectivity between diploid populations from the Central Zambezian region (i.e., strong isolation by distance; Figure 6) probably makes complete homogenization of photosynthetic types very slow and potentially impossible.…”

Contrasted histories of organelle and nuclear genomes underlying physiological diversification in a grass species

“…Instead, the sister group relationship between nuclear clades III and IV, which are associated with divergent organelles, suggests the swamping of one nuclear genome lineage by the other ( figure 4 ). The directionality of this exchange is unknown, but repeated, unidirectional gene flow mediated by pollen must have occurred in a region where only monoparentally inherited organelles persisted [ 56 ], as previously reported for other taxa [ 57 ]. One of these organelle lineages originates from the Central Zambezian highlands (lineage FG), while the other originates from the lowlands of eastern Africa (lineage DE; figure 1 ).…”