TY  - JOUR
AU  - Dathe, A.
AU  - Postma, Johannes Auke
AU  - Postma-Blaauw, M. B.
AU  - Lynch, J. P.
TI  - Impact of axial root growth angles on nitrogen acquisition in maize depends on environmental conditions
JO  - Annals of botany
VL  - 118
IS  - 3
SN  - 1095-8290
CY  - Oxford
PB  - Oxford University Press
M1  - FZJ-2016-04446
SP  - 401-414
PY  - 2016
AB  - Backgrounds and Aims Crops with reduced requirement for nitrogen (N) fertilizer would have substantial bene-fits in developed nations, while improving food security in developing nations. This study employs the functionalstructural plant model SimRoot to test the hypothesis that variation in the growth angles of axial roots of maize (Zeamays L.) is an important determinant of N capture. Methods Six phenotypes contrasting in axial root growth angles were modelled for 42 d at seven soil nitrate lev-els from 10 to 250 kg ha À1 in a sand and a silt loam, and five precipitation regimes ranging from 0Á5Â to 1Á5Â ofan ambient rainfall pattern. Model results were compared with soil N measurements of field sites with silt loam andloamy sand textures. Key Results For optimal nitrate uptake, root foraging must coincide with nitrate availability in the soil profile,which depends on soil type and precipitation regime. The benefit of specific root architectures for efficient N uptakeincreases with decreasing soil N content, while the effect of soil type increases with increasing soil N level.Extreme root architectures are beneficial under extreme environmental conditions. Extremely shallow root systemsperform well under reduced precipitation, but perform poorly with ambient and greater precipitation. Dimorphicphenotypes with normal or shallow seminal and very steep nodal roots performed well in all scenarios, and consis-tently outperformed the steep phenotypes. Nitrate uptake increased under reduced leaching conditions in the siltloam and with low precipitation. Conclusions Results support the hypothesis that root growth angles are primary determinants of N acquisition inmaize. With decreasing soil N status, optimal angles resulted in 15–50 % greater N acquisition over 42 d. Optimalroot phenotypes for N capture varied with soil and precipitation regimes, suggesting that genetic selection for rootphenotypes could be tailored to specific environments.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000383591200003
C6  - pmid:27474507
DO  - DOI:10.1093/aob/mcw112
UR  - https://juser.fz-juelich.de/record/817807
ER  -