The New Is Old: Novel Germination Strategy Evolved From Standing Genetic Variation in Weedy Rice

Area of Science:

• Plant biology
• Evolutionary genetics
• Agricultural science

Background:

• Feralization of crops leads to reduced yield and novel traits.
• Weedy rice (Oryza sativa f. spontanea) is a conspecific weed with independent origins.

Purpose of the Study:

• Investigate the genetic mechanisms of feralization and local adaptation in weedy rice.
• Understand the evolution of germination control in weedy rice populations.

Main Methods:

• Integrative analysis of phenotypic, genomic, and transcriptomic data.
• Identification of genes with allele frequency differences and expression correlations.
• Tracing the origin of adaptive alleles in wild and cultivated rice genomes.

Main Results:

• Weedy rice evolved temperature-sensing germination control, not seed dormancy.
• Divergence in minimum germination temperature between eastern and northeastern China populations.
• Identified genes with extreme allele frequency differences and linked to feral phenotypes.

Conclusions:

• Weedy rice utilizes pre-existing, conditionally neutral alleles for adaptation during feralization.
• Activation of formerly silent alleles facilitates the transition to a wild existence.
• This mechanism promotes the evolution and persistence of weedy rice forms.