Weedy rice (Oryza spp) is an aggressive weed of cultivated rice, causing up to 30% annual reduction in crop productivity worldwide. Being unwanted plants in the agricultural environment, weedy rice varieties offer striking examples of rapid evolution and adaptation. Although independent evolutionary events have been reported, with weed sub-groups having diverse ancestries, many weedy rice varieties possess common weed adaptive traits considered as “agricultural weed syndrome”. The evolution of similar weed adaptive traits in different groups makes weedy rice a perfect system to study parallel or convergent evolution.

My PhD thesis research explains the multiple origins of South Asian weedy rice, including cultivated varieties and local wilds, using next-generation-sequencing tools and population genetics analysis. Genomic scans have also been conducted to detect candidate regions making weedy rice different from their ancestors.

By characterizing a list of known genes under weedy traits (eg. seed shattering, red pericarp), I have discovered multiple mechanisms of acquiring the same weedy traits in various weed sub-groups. Further greenhouse physiology experiments and RNA-seq approach have been applied to reveal more about the genomics underlying of weed competitiveness.