The correlative change of pigments with chromoplast morphogenesis in the pericarpof yellow and red pimentos during fruit ripening was examined by pigment spectrophotometryand electronmicrosopy. The metamorphosis of plastids, chloroplasts to chromoplasts, occurredwith the decrease of chlorophyll contents and the appearance of newly synthesized carotenoids,chloroxanthin in yellow pimentos and possibly capsanthin and/or capsorubin in red pimentos.As ripening proceeded, in plastids, plastoglobuli increased in both number and size, in contrastwith the degradation of grana-stack and the fragmentation of stromal thylakoids. The plastidsof yellow-ripe fruit pericarps contained exclusively plastoglobuli of various sizes at the center ofstroma, indicating G (globular)-type chromoplasts, while the plastids of red-ripe fruit pericarpsincluded a few enlarged plastoglobuli and electron-dense inclusions of various configurations,which possibly transformed from plastoglobuli to finally form needle-shaped carotenoidcrystalloids. They were determined as an intermediate-type between G-type and F (filament)-typechromoplasts, and it was reconfirmed that, during chromoplast maturation, needle-shapedcarotenoid crystalloids are formed by the elongation of enlarged plastoglobuli, concomitant withthe increase of cartotenoid contents
