Dear Editor,Brassica rapa is an important crop and a model plant for studying Brassica genome evolution and gene function.The silique of B.rapa derived from the gynoecium normally consists of two carpels that are separated by a false septum,and thus has two locules (bilocular).Multilocular (more than two carpels) lines of B.rapa have been discovered in nature and are considered advantageous because the multilocular type could potentially increase the seed yield by producing more seeds per silique than the bilocular type.However,the molecular basis of the important seed yield-related trait is poorly understood.