**Acknowledgements**

The authors would like to acknowledge the National Natural Science Foundation of China [U1903105 and 31872943] and the Natural Science Foundation of Shandong Province [ZR2019MC067] for their support.

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**Author details**

Yanyan Yan1,2,3,4, Qinghua Shi1,2,3,4 and Biao Gong1,2,3,4\*

\*Address all correspondence to: gongbiao@sdau.edu.cn

provided the original work is properly cited.

2 Collaborative Innovation Center of Fruit and Vegetable Quality and Efficient

3 Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Huanghuai Region, Ministry of Agriculture and Rural Affairs, P.R. China

4 College of Horticulture Science and Engineering, Shandong Agricultural

1 State Key Laboratory of Crop Biology, P.R. China

Production in Shandong, P.R. China

University, Taian, P.R. China

*Review of Melatonin in Horticultural Crops DOI: http://dx.doi.org/10.5772/intechopen.90935* *Review of Melatonin in Horticultural Crops DOI: http://dx.doi.org/10.5772/intechopen.90935*

*Melatonin - The Hormone of Darkness and Its Therapeutic Potential and Perspectives*

promoting growth and anti-stress regulation mechanism and the successful cases of exogenous melatonin promoting crop growth and enhancing resistance are expected to make great contributions to the high yield and high-quality production of horticultural crops. Based on the current research status, we make a prediction on the application of melatonin in horticulture production, hoping to attract more and more attention. (1) For cucumbers and others prone to premature aging, horticultural crops can be applied by exogenous melatonin to alleviate the aging process. (2) Leek, asparagus and most fruit trees show aging trend with the extension of cultivation year. The application of exogenous melatonin also plays a role in the rejuvenation of this kind of aging horticultural crops. (3) Taking advantage of the anti-aging and drought resistance properties of melatonin, it can be used for fresh cut flowers, fruits and leafy vegetables. (4) Melatonin can promote root growth and withstand low temperature in plants, alleviating the reduction in root growth and absorption of fertilizer and water that are caused by the excessive low ground temperature, thereby reducing heating costs, improving the utilization rate of CO2, and promoting the efficacy of fertilizer. (5) At present, shade means are often used in the over-summer cultivation of ginger and other light-tolerant and shade-tolerant horticultural crops to reduce leaf senescence and root loss caused by the damage of strong light to leaf photosynthetic organs. Melatonin is introduced into the cultivation technology of this type of crops by utilizing the mechanism of accumulation of melatonin in chloroplast and protection of photosynthetic organs and inhibition of leaf senescence. (6) In cucumber and pumpkin grafting, the technology of double broken root grafting is often adopted. Melatonin can promote the occurrence of adventitious root and prevent the infection of wound. At the same time, melatonin also has the function of promoting graft wound healing, which has great application potential in some fruit trees and flowers with low graft survival rate. (7) Taking advantage of the characteristics of melatonin in delaying senescence, MT is used as a flower-/fruit-preserving agent for vegetable crops in winter and summer to improve pollen vitality, increase fruit setting rate and reduce malformation fruit rate. (8) As a plant growth regulator, melatonin can be used in plant growth promotion and disease prevention to reduce the use of pesticides. Moreover, as a new type of growth regulation substance, it has the characteristics of high efficiency and environmental protection. Its development and utilization can greatly promote the healthy growth of horticultural crops, improve the fertilizer utilization ratio and reduce the occurrence of plant diseases and insect pests and pesticide dosage. It can play an important role in the process of using fewer chemical fertilizers and pesticides in China, and has a great development potential in promoting the healthy

The authors would like to acknowledge the National Natural Science Foundation

of China [U1903105 and 31872943] and the Natural Science Foundation of

Shandong Province [ZR2019MC067] for their support.

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development of horticulture industry.

**Acknowledgements**
