Abstract: Golden yellow bean pod‘A18’and green bean‘Genoa’were chosen as experimental materials to study the expressing mechanism of color in golden bean pods. The formation mechanism of the golden pod color of kidney bean was studied by determining the amount of related metabolin in the synthetic pathway of chlorophyll，carotenoid，and chlorophyll during pod development in its wall. The results indicated the golden color of tender pod was resulted from the lack of chlorophyll content，which was speculated by the inhibition of chlorophyllide a synthesis. The expression pattern of chlorophyll biosynthesis-related genes was analyzed by real-time PCR. Indeed，the analysis suggested the expression levels of CHLM and DVR decreased in‘A18’from the 12th day after flowering. While the expression levels of CHLP，CHLG and CAO were higher than those in‘Genoa’at multiple time points，indicating that although chlorophyllide a synthesis is blocked，chlorophyll synthesis is still active.

Key words: Phaseolus vulgaris, pod color, photosynthetic pigment, chlorophyll synthesis pathway, chlorophyll synthesis related gene