*Review* **Heat Stress in Cotton: A Review on Predicted and Unpredicted Growth-Yield Anomalies and Mitigating Breeding Strategies**

**Sajid Majeed 1, Iqrar Ahmad Rana 2, Muhammad Salman Mubarik 2, Rana Muhammad Atif 1, Seung-Hwan Yang 3, Gyuhwa Chung 3,\*, Yinhua Jia 4, Xiongming Du 4, Lori Hinze <sup>5</sup> and Muhammad Tehseen Azhar 6,7,\***


**Citation:** Majeed, S.; Rana, I.A.; Mubarik, M.S.; Atif, R.M.; Yang, S.-H.; Chung, G.; Jia, Y.; Du, X.; Hinze, L.; Azhar, M.T. Heat Stress in Cotton: A Review on Predicted and Unpredicted Growth-Yield Anomalies and Mitigating Breeding Strategies. *Agronomy* **2021**, *11*, 1825. https://doi.org/10.3390/agronomy 11091825

Academic Editors: Channapatna S. Prakash, Ali Raza, Xiling Zou and Daojie Wang

Received: 4 August 2021 Accepted: 9 September 2021 Published: 12 September 2021

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**Abstract:** The demand for cotton fibres is increasing due to growing global population while its production is facing challenges from an unpredictable rise in temperature owing to rapidly changing climatic conditions. High temperature stress is a major stumbling block relative to agricultural production around the world. Therefore, the development of thermo-stable cotton cultivars is gaining popularity. Understanding the effects of heat stress on various stages of plant growth and development and its tolerance mechanism is a prerequisite for initiating cotton breeding programs to sustain lint yield without compromising its quality under high temperature stress conditions. Thus, cotton breeders should consider all possible options, such as developing superior cultivars through traditional breeding, utilizing molecular markers and transgenic technologies, or using genome editing techniques to obtain desired features. Therefore, this review article discusses the likely effects of heat stress on cotton plants, tolerance mechanisms, and possible breeding strategies.

**Keywords:** breeding; climate change; genetics; heat stress; upland cotton
