Effects Of Light Intensity And Nitrogen Fertilizer On Capsaicin Metabolism,Quality And Yield Of Hot Pepper

Hot pepper (Capsicum annuum L.) fruits have abundant nutrition and specialties in flavor. Pepper fruits have the highest content of Vc among all kinds of vegetables as well as abundant capsaicin. The increase of planting and consumption continue in the whole world. Because of the health-care function of capsaicin in pepper fruits, people pay more and more attention to the production and consumption of hot pepper.Both laboratory and field experiment were carried out to research the effects of three different light intensity and three nitrogen fertilizer levels on capsaicin metabolism, quality and yield of hot pepper fruits during maturation, and the effects of two light condition on capsaicin metabolism during storage after picked, the varieties used in the study were in different hot levels named No.4 Xiangyan and No.3 Jingjianjiao. After systemic experiment and analyses, the study drew the conclusion as listed below:1. The shading treatment increased the synthesis and accumulation of capsaicin.The shading treatment increased the synthesis and accumulation of capsaicin. The influence of light intensity became more and more obviously companied with the maturation, both the placenta and the pericarp part of the pepper fruits showed increasing tendency of capsaicin content under increasing shading tendency.2. During the short storing stage after picked, light condition was more advantageous for capsaicin content increasing in pericarp and lightless condition was more advantageous for capsaicin content increasing in placenta of pepper fruits.3. Under the experiment condition, high nitrogen level was disadvantageous for the synthesis of capsaicin.The content of capsaicin showed decreasing tendency companied with increasing nitrogen fertilizer levels in the experiment especially in the mature stage.4. The shading treatment lowed the content of Vc and soluble sugar in pepper fruits.With increasingly shading, the data showed decreasing content of Vc and soluble sugar in pepper fruits. This result clarified that shading was disadvantageous for the synthesis of Vc and soluble sugar.5. More nitrogen fertilizer lowed the content of Vc and soluble sugar in pepper fruits.The data showed decreasing content of Vc and soluble sugar in pepper fruits when given more nitrogen fertilizer. This result showed that more nitrogen fertilizer decrease the synthesis of Vc and soluble sugar in pepper fruits under certain range. 6. The shading treatment could enhance the yield of pepper.For No.4 Xiangyan, the yield of 20% shading treatment was the highest, it was significant higher than 40% shading treatment, the former two treatment were very significant higher than 100% nature light treatment. For No.3 Jingjianjiao, the 40% shading treatment had the highest yield, it was very significant higher than 20% shading treatment, the yield of 20% shading treatment was significant higher than 100% nature light treatment.7. In this study, the treatment used 20kg N per 667㎡ had the highest yield, it was very significant higher than the treatment used 10kg N per 667㎡, the yield of treatment used 10kg N per 667㎡was very significant higher than the treatment used 30kg N per 667㎡.Postgraduate: Wang JinlingMayor: OlericultureSupervisor: Prof. Yu Guangjian...