Herbicide resistance is an evolutionary process that affects entire agricultural regions' yield and productivity. The high number of farms and the diversity of weed management can generate hot selection spots along regions. Resistant biotypes can present a diversity of mechanisms of resistance and resistance factors depending on selective conditions inside the farm; this situation is similar to predicts by the geographic mosaic theory of coevolution. In Mexico, the agricultural region of Bajio has been affected by herbicide resistance for 25 years. To date, Avena fatua L. is one of the most abundant and problematic weed species. The objective of this study was to determine the mechanism of resistance of biotypes with failures in the weed control in 70 wheat and barley crop fields in Bajio, Mexico. The results showed that 70% of farms have biotypes with TSR, the most common mutations where Trp – 1999 – Cys, Asp – 2078 – Gly, Ile – 2041 – Asn, such mutations confer cross-resistance to ACCase-inhibiting herbicides. Metabolomic fingerprinting showed four different metabolic expression patterns. The results confirmed that in the Bajio exist multiple selection sites for both resistance mechanisms, which proves that this area can be considered as a geographic mosaic of resistance.

To understand SARS-CoV-2 microevolution, this study explored the genome-wide frequency, gene-wise distribution, and molecular nature of all point-mutations detected across its 71,703 RNA-genomes deposited in the GISAID repository, till 21 August 2020. Globally, nsp1/nsp2/nsp3/ nsp11 and orf7a/orf3a/S were the most mutation-ridden non-structural and structural genes respectively. Phylogeny based on 4,618 spatiotemporally-representative genomes revealed that entities belonging to the early lineages are mostly spread over Asian countries (including India, the biggest hotspot of the pandemic) whereas the recently-derived lineages are more globally distributed. Of the total 16,602 polymorphism-bearing sites in the pan-genome, 11,037 and 4,965 involved transitions and transversions, which in turn were predominated by cytidine-to-uridine and guanosine-to-uridine conversions, respectively. Positive selection of nonsynonymous mutations (dN/dS >1) in most of the structural, but not non-structural, genes indicated that SARS-CoV-2 has already harmonized its replication/transcription machineries with the host’s metabolic system, while it is still redefining virulence/transmissibility strategies at the molecular level.