A novel Brassica–rhizotron system to unravel the dynamic changes in root system architecture of oilseed rape under phosphorus deficiency

Yuan, Pan; Ding, Guangda; Cai, Hongmei; Jin, Ke-Mo; Broadley, Martin R.; Xu, Fangsen; Shi, Lei

Abstract

Background and Aims: An important adaptation of plants to phosphorus (P) deficiency is to alter root system architecture (RSA) to increase P acquisition from the soil, but soil-based observations of RSA are technically challenging, especially in mature plants. The aim of this study was to investigate the root development and RSA of oilseed rape (Brassica napus L.) under low and high soil P conditions during an entire growth cycle.

Methods: A new large Brassica–rhizotron system (approx. 118-litre volume) was developed to study the RSA dynamics of B. napus ‘Zhongshuang11’ in soils, using top-soils supplemented with low P (LP) or high P (HP) for a full plant growth period. Total root length (TRL), root tip number (RTN), root length density (RLD), biomass and seed yield traits were measured.

Key Results: TRL and RTN increased more rapidly in HP than LP plants from seedling to flowering stages. Both traits declined from flowering to silique stages, and then increased slightly in HP plants; in contrast, root senescence was observed in LP plants. RSA parameters measured from the polycarbonate plates were empirically consistent with analyses of excavated roots. Seed yield and shoot dry weights were closely associated positively with root dry weights, TRL, RLD and RTN at both HP and LP.

Conclusions: The Brassica–rhizotron system is an effective method for soil-based root phenotyping across an entire growth cycle. Given that root senescence is likely to occur earlier under low P conditions, crop P deficiency is likely to affect late water and nitrogen uptake, which is critical for efficient resource use and optimal crop yields.

Citation

Yuan, P., Ding, G., Cai, H., Jin, K., Broadley, M. R., Xu, F., & Shi, L. (in press). A novel Brassica–rhizotron system to unravel the dynamic changes in root system architecture of oilseed rape under phosphorus deficiency. Annals of Botany, 118(2), https://doi.org/10.1093/aob/mcw083

• Journal Article Type: Article
• Acceptance Date: Mar 16, 2016
• Online Publication Date: Jun 8, 2016
• Deposit Date: Nov 18, 2016
• Publicly Available Date: Nov 18, 2016
• Journal: Annals of Botany
• Print ISSN: 0305-7364
• Electronic ISSN: 1095-8290
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 118
• Issue: 2
• DOI: https://doi.org/10.1093/aob/mcw083
• Keywords: oilseed rape (Brassica napus L.), phosphorus deficiency, root system architecture, dynamic changes, Brassica-rhizotron
• Public URL: https://nottingham-repository.worktribe.com/output/796167
• Publisher URL: http://aob.oxfordjournals.org/content/118/2/173
• Additional Information: This is a pre-copyedited, author-produced version of an article accepted for publication in Annals of Botany following peer review. The version of record A novel Brassica–rhizotron system to unravel the dynamic changes in root system architecture of oilseed rape under phosphorus deficiency /; Pan Yuan, Guang-Da Ding, Hong-Mei Cai, Ke-Mo Jin, Martin Roger Broadley, Fang-Sen Xu, and Lei Shi, volume 118, issue 2, pp. 173-184 is available online at: http://aob.oxfordjournals.org/content/118/2/173.abstract. doi: 10.1093/aob/mcw083