African Orphan Crops under Abiotic Stresses: Challenges and Opportunities

Table 3

Mechanisms of orphan crops tolerance to diverse abiotic stresses.

Abiotic stress	Trait	Response to stress	Crop	Reference
Drought	Seed yield	High yield for drought-tolerant genotypes	Pearl millet	[29]
	Flowering time	Adjust phenology to rainfall pattern	Pearl millet	[30]
	Shoot length	Decreased under drought	Little millet	[31]
	Root length	Increased under drought	Little millet	[31]
	Leaf tensile strength	Increased in drought-tolerant plants	Tef	[32]
	Water extraction	Less extraction before flowering; more extraction after flowering	Pearl millet	[29]
	Chlorophyll content	Decreased under drought	Little millet	[31]
Waterlogging	Cellular structure	Aerenchyma formation	Sunflower	[33]
		Formation of adventitious roots	Sorghum, finger millet	[34, 35]
	Metabolism	Generation of antioxidants	Pigeon pea	[36]
		Change to anaerobic metabolism	Finger millet	[37]
	Plant height	Fast growth	Mung bean	[38]
Heat	Growth	Growth and nutrient uptake	Chickpea, Pearl millet	[39, 40]
	Yield	Unknown	Cowpea	[41]
Cold and frost	Growth	Early flowering, protracted rosette	Faba bean	[42]
		Early flowering	Sorghum	[43]