Shoot and root traits in drought tolerant maize (Zea mays L.) hybrids

Authors: ZHAO, JIN - Agrilife Research; XUE, QINGWUE - Texas Agrilife; JESSUP, KIRK - Agrilife Research; HOU, XIAOBO - Agrilife Research; HAO, BAOZHEN - Agrilife Research; MAREK, THOMAS - Agrilife Research; XU, WENWEI - Agrilife Research; Evett, Steven - Steve; O`Shaughnessy, Susan; Brauer, David

Submitted to: Journal of Integrative Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2017
Publication Date: 1/10/2018
Citation: Zhao, J., Xue, Q., Jessup, K.E., Hou, X., Hao, B., Marek, T., Xu, W., Evett, S.R., O'Shaughnessy, S.A., Brauer, D.K. 2018. Shoot and root traits in drought tolerant maize (Zea mays L.) hybrids. Journal of Integrative Agriculture. 17(0):60345-60347. https://doi.org/10.1016/S2095-3119(17)61869-0.
DOI: https://doi.org/10.1016/S2095-3119(17)61869-0

Interpretive Summary: Water availability for irrigation from the Ogallala Aquifer is decreasing and future corn production will necessitate the use of drought tolerant varieties. However the traits that confer drought tolerance in corn are poorly understand. Scientists from ARS (Bushland, TX) and Texas A&M AgriLife research investigated the differences in shoot and root traits, and water use and water use efficiency in drought tolerant (DT) maize hybrids under full and deficit irrigated conditions. Two of the DT hybrids are commercially available and the third is an experimental hybrid. The commercial and experimental DT hybrids demonstrated different drought tolerance mechanisms that may require different irrigation management strategies. More investigation and validation is needed under field conditions and in different soil types.

Technical Abstract: This study aimed to investigate the differences in shoot and root traits, and water use and water use efficiency in drought tolerant (DT) maize (Zea mays L.) hybrids under full and deficit irrigated conditions. A two-year greenhouse study was conducted with four hybrids (oneconventional hybrid, 33D53AM, and three DT hybrids, P1151AM, N75H, and ExpHB) grown under two water regimes (I100 and I50, referring to 100 and 50% of evapotranspiration requirements). All the shoot and root traits, and water use and water use efficiency (WUE) were affected by water regime and hybrid. Under water stress, the three DT hybrids showed more drought tolerance than the conventional hybrid, but they responded to water stress using different mechanisms. Compared with the conventional hybrid, the two commercial DT hybrids (P1151AM and N75H) had a smaller leaf area, shoot dryweight, and root system. As a result, these hybrids used less water and had a higher WUE compared with the conventional hybrid. In contrast, the experimental DT hybrid (ExpHB) had produced more shoot biomass by the silking stage in both irrigation levels as compared with all other hybrids, but it had relatively low WUE. The commercial and experimental DT hybrids demonstrate different drought tolerance mechanisms that may require different irrigation management strategies. More investigation and validation is needed under field conditions and in different soil types.