Chitosan oligosaccharide (COS) is one of natural bio-stimulants obtained from the degradation of chitin or chitosan. COS has many advantages, such as easy accessibility, high water solubility, low viscosity, non-toxicity, biocompatibility, biodegradability, and high bioactivity . Because of this, COS has attracted much attention in the agricultural sector, particularly for organic agricultural practices that do not harm the environment. Numerous studies have demonstrated the crucial role of COS in controlling plant growth , seed germination , photosynthetic components , secondary metabolism , and tolerance to abiotic and biotic stress .
Previous research on tomatoes has focused on the impact of COS on plant growth, resistance, and yield . the current study focused on the impacts of COS on tomato color, firmness, nutritional content, and flavor. COS was administered to tomato plants (Solanum lycopersicum cv. Ruixinghongniu) by foliar spray and root irrigation in alternate cycles at concentrations of 0.5 g·L −1 and 0.16 g·L −1 , respectively. The experimental outcomes revealed that COS promoted fruit coloring and softening and increased the contents of health-promoting compounds (lycopene and vitamin C). It also enhanced the accumulation of soluble sugars (fructose and glucose) and flavor-associated volatiles that improve taste. The analysis of ethylene production and signaling pathways suggested that COS could improve fruit quality by augmenting ethylene biosynthesis, perception, and response. These findings help us to better understand the role of COS in fruit ripening and quality improvement and provide theoretical support for its practical application in sustainable tomato production.
Figure
1. Effect of COS on the coloring (a) and firmness (b) of tomato fruits. In (b), data represent the means ± SD of six fruits. The asterisk represents a significant difference compared with the con‐ trol based on Student’s t‐test (* p < 0.05). MG: mature green; B: breaker; P: pink; RR: red ripened. FW: fresh weight.
Reference:Quality Improvement of Tomato Fruits by Preharvest Application of Chitosan Oligosaccharide