Identifying plant traits to increase chickpea yield in water-limited environments

Average chickpea (Cicer arietinum L.) yield is low in major producer countries, which in nearly all cases is a consequence of water-deficit conditions. A first step in increasing crop yield under drought is to identify drought traits that are likely to be beneficial. In this study, we examined potential benefits of six modified drought traits in chickpea in two contrasting water-limited environments. Simulations were performed over 30 seasons for two soil depths (120 and 80 cm) at Tabriz and Gonbad, Iran, representing the environmental diversity among major chickpea producing areas. Delayed stomata closure with respect to soil drying resulted in decreased yield. A slower rate of leaf development did not lead to yield improvement. Four other traits increased crop yield. Increased depth of water extraction from the soil provided the greatest yield increase that varied from 14% in a deep soil at Gonbad (wetter environment) to 45% in a shallower soil at Tabriz (drier environment). Slower rate of growth (crop mass production) was the second important trait which resulted in 6–8% yield increase in 120-cm-soil and 21% yield increase in 80-cm-soil. The priority of other traits to increase crop yield depended on soil depth. In 120-cm-soil, reduced maximum transpiration rate improved crop yield (5–7%). Yield enhancement as a result of early stomata closure with respect to soil drying was ≤3% in this soil. In 80-cm-soil, however, early stomata closure with respect to soil drying was the third most beneficial drought traits in increasing yield (13–16%). Reduced maximum transpiration rate resulted in 3 and 6% yield increase at 80-cm-soil in Tabriz and Gonbad, respectively. It was concluded that deeper rooting, slower rate of growth, early stomata closure and reduced maximum transpiration rate are key target traits for genetic improvement in chickpea in water-limited environments with terminal droughts.

► We investigated key target plant traits to increase chickpea yield under terminal drought.
► Simulations performed in two contrasting water-limited environments.
► Increased rooting depth provides the greatest yield increase (14–45%).
► Slower rate of plant growth is the second important trait (6–21% yield increase).
► Early stomata closure and reduced maximum transpiration rate are also beneficial.