Quantifying the response of wheat (Triticum aestivum L) root system architecture to phosphorus in an Oxisol
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Background and aims
Despite the recognised importance of root architecture to plant productivity, our ability to easily observe and quantify root responses to stresses in soil at appropriate mechanistic resolution, remains poor. In this study we examine the impact of P bands on root architecture in heterogeneous soil, trialling a rapid non-destructive analysis technique.
We examined fast (<5 min), high resolution (69 μm voxels) x-ray tomography (μCT) to non-destructively observe and quantify wheat (Triticum aestivum L.) roots in a repacked Oxisol, in 3D, with and without a band of P-enriched soil.
We found that wheat roots displayed localised responses (were plastic) and responded with additional root length within the banded P fertiliser. The seedling root systems also altered 3D root architecture in the band by increasing the number and length of branch roots. Branch root angle was not altered by the P band. The spatial precision of the branching response was striking and raises questions concerning the root sensing and/or response mechanisms.
KeywordsTriticum aestivum Soil structure Root architecture Tomography X-rays
We thank G. Falzon for statistical advice and Kernel smoothing algorithm. This research was in part funded by The University of New England, the CSIRO OCE Postgraduate Scholarship, and the Grains Research and Development Corporation - Grains Industry Research Scholarship.
- Breiman L, Friedman J, Olshen R, Stone C (1984) Classification and Regression Trees. Wadsworth.Google Scholar
- Hadfield J (2010) MCMC methods for multi-response generalised linear mixed models: the MCMCglmm R package. J Stat Softw 33:1–22Google Scholar
- Helliwell JR, Sturrock CJ, Grayling KM, Tracy SR, Flavel RJ, Young IM, Whalley WR, Mooney SJ (2103) Applications of X-ray computed tomography for examining biophysical interactions and structural development in soil systems: a review. Eur J Soil Sci 64:279–297Google Scholar
- Henry A, Chaves N, Kleinman P, Lynch J (2010) Will nutrient-efficient genotypes mine the soil? Effects of genetic differences in root architecture in common bean (Phaseolus vulgaris L.) on soil phosphorus depletion in a low-input agro-ecosystem in central America. Field Crop Res 115:67–78CrossRefGoogle Scholar
- Jackson R, Caldwell M (1989) The timing and degree of root proliferation in fertile-soil microsites for three cold-desert perennials. Oecologia 81:149–153Google Scholar
- R Development Core Team (2010) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, AustriaGoogle Scholar
- Robinson D (2005) Integrated root responses to variations in nutrient supply. In: Nutrient acquisition by plants- an ecological perspective (ed H. BrassiriRad). Springer-Verlag, Heidelberg Berlin, Germany.Google Scholar
- Tinker P, Nye P (2000) Solute movement in the rhizosphere. Oxford University Press, New YorkGoogle Scholar
- Watson G (1964) Smooth regression analysis. Sankhya Indian J Statistic 26:359–372Google Scholar