Drought stress in sorghum: Mitigation strategies, breeding methods and technologies—A review

Abstract

Agriculture accounts for 70% of the global use of available freshwater. Projections show that demand for water will increase significantly due to climate change, population growth and development of agricultural enterprises globally. There is a need to develop water-use efficient crop cultivars for sustainable agricultural production.Sorghum [Sorghum bicolor (L.) Moench.] is a powerhouse crop in drier regions supporting more than 500 million people. It is a relatively drought-tolerant crop adapted to grow and yield in marginal environments where other dominant crops such as maize and wheat fail to survive. However, the mean yield of sorghum in the semi-arid regions has stagnated around 1.0 ton/ha compared with the global average of 2.5 ton/ ha, mainly due to recurrent droughts and heat stress. Breeding for drought-tolerant cultivars is an economic and sustainable mitigation strategy against the current and projected drought stress. Therefore, the objectives of this review were to document the impact of drought stress and the key mitigation strategies under drought-prone semi-arid sorghum production systems. The first section of the review highlighted the impact of drought and its mitigation strategies emphasizing on the use of droughttolerant cultivars as the best strategy. This is followed by perspectives on aspects of drought-response mechanisms, breeding methods and complementary technologies for drought tolerance. Integration of the conventional and molecular breeding technologies with rapid generation advancement methods could reduce the breeding cycle and increase the efficiency of deploying new varieties. Information presented in this review will guide agronomists and breeders to develop and deploy droughttolerant sorghum cultivars that are adapted to the changing production environments in the semi-arid regions.

Plants’ Physio-Biochemical and Phyto-Hormonal Responses to Alleviate the Adverse Effects of Drought Stress: A Comprehensive Review

“…Changing climatic regimes are posing a threat to life on Earth because meeting the rising food demand and achieving sustainable agriculture for a growing population is becoming an uphill task in the present scenario of changing climatic conditions [1], which include droughts, heavy floods, earthquakes, and temperature variations [2,3]. Drought stress interrupts many physio-biochemical processes, hindering plant growth and development [4,5]. Plants can frequently withstand limited water conditions but at the cost of substantial loss in total biomass and productivity.…”

Probabilistic modeling of crop-yield loss risk under drought: a spatial showcase for sub-Saharan Africa

“…In the case of sorghum, the short maturity period of some of its varieties-as early as 65-70 d after sowing-is another reason for extending its area in less suitable regions where length of rainy season limits crop production [75]. The early maturing varieties of sorghum not only characterized by yield penalty, but with considerable yield loss, up to 87% of grain yield, under drought stress [76,77]. In addition, literature shows that sorghum show very different drought response to climatic patterns [78].…”

Improving Drought Stress Tolerance in Ramie (Boehmeria nivea L.) Using Molecular Techniques

“…Abiotic stresses are causing a huge decline in crop growth and production worldwide ( Fahad and Bano, 2012 ; Fahad et al, 2013 , 2017 , 2019a , Fahad et al, 2021c , Bamagoos et al, 2021 ). Drought stress (DS) is the worst environmental factor around the globe and severely affects crop yield ( Anjum et al, 2011 ; Alharby and Fahad, 2020 ; Seleiman et al, 2021 ; Yahaya and Shimelis, 2022 ). DS is an inevitable abiotic aspect in numerous ecological areas, severely declining crop yield and quality without warning before its onset ( Seleiman et al, 2021 ; Bandurska, 2022 ).…”