Chloroplast Composition and Structural Differences in a Chlorophyll-reduced Mutant of Oilseed Rape Seedlings Study on the Spectra Properties of Cotyledon Thylakoid Membranes in Chlorophyll -reduced Rapeseed Mutant Cr3529 and its Wild Type Photosynthetic Characteristics and Chlorophyll Fluorescence Kinetic Parameters Analyses of Chlorophyll-Reduced Mutant in Brassica napus L. Photosynthetic Physiological Characteristics and Chloroplast Ultrastructure of Yellow Leaf Mutant YL-1 in Cabbage Photosynthetic Physiological Characteristics and Chloroplast Ultrastructure of Yellow Leaf Mutant YL-1 in Cabbage