A comparison of three isolines of cotton differing in fiber color for yield, quality, and photosynthesis
Naturally colored cotton (Gossypium hirsutum L.) fibers (CCFs) are eco-friendly for the textile industry because they omit the dyeing process and reduce harmful effluent liquor. However, the low yield and quality of CCFs have greatly affected their development. Limited information is available on the reasons for the low yield and quality of CCFs. The aim of this 2-yr investigation was to compare variations in chlorophyll concentration, net photosynthesis rate, monosaccharide concentration, and fiber yield and quality among white-fiber cotton (WFC), brown-fiber cotton (BFC), and green-fiber cotton (GFC). White-fiber cotton had the highest lint yield, which was on average 33.6 and 41.9% higher than that of BFC and GFC, respectively. Other yield components such as boll number and boll weight had similar trends in both years. The fiber length of GFC and BFC was reduced by 17.4 and 11.1%, respectively, compared with that of WFC. These results indicated that GFC had the lowest fiber yield and quality. Leaf chlorophyll concentration, net photosynthesis rate, and fructose and glucose concentrations of GFC were slightly higher than those of WFC, indicating its active photosynthesis. However, its vigorous vegetative growth had reduced its reproductive growth, partly resulting in low yield and quality. Brown-fiber cotton had the lowest leaf chlorophyll concentration and other photosynthetic indexes, leading to a lower amount of photosynthetic product and, hence, yield and quality.