Abstract
Two accredited cotton (Gossypium hirsutum L.) cultivars (Aleppo 118 and Deir Al-Zour 22) have been investigated to assess physiological, morphological, and molecular responses under water shortage conditions. Both cultivars have shown early flowering. However, higher percentage of treated ‘Aleppo 118’ plants kept flowering towards the end of the growing season compared to treated ‘Deir Al-Zour 22’ plants. Both cultivars kept consistent micronaire and cohesion under normal and water shortage conditions. The cultivar Aleppo 118 displayed more consistent fiber quality between control and treated plants, while ‘Deir Al-Zour 22’ showed variation in fiber length and strength between control and treated plants. Results have demonstrated an increase in fold expression of DREB1A, TPS and HSPCB genes in the flowering stage of treated plants compared to the controls. Results also showed a continuous activation of DREB1A gene in the two critical growing stages of a cotton life cycle, flowering and boll development in treated plants of ‘Deir Al-Zour 22’. This work illustrates the different responses of two cotton cultivars under water shortage stress and its impact on flowering and fiber traits
