In recent years, weedy rice has appeared one after another in the paddy fields all over the world, which directly lead to the reduction of yield and quality of the paddy fields, and even the loss of harvest in the seriously damaged paddy fields. This kind of weedy rice is domesticated and adapted to the environment through genomic variation and has a strong growth advantage that normal rice does not have. 
Weedy rice is extremely difficult to distinguish from normal rice in appearance and cannot be easily removed.
 many people think that their existence will seriously affect the yield of normal rice.