Abstract

Aims The objectives of this study were to assess how Arachis hypogaea L. (peanut or groundnut) responds to different P supplies in terms of growth and photosynthesis, and to determine the optimum P supply and differential P stress thresholds. Methods We investigated biomass production, leaf expansion, photosynthetic parameters, relative chlorophyll concentration, P700 parameters and chlorophyll fluorescence in a climate-controlled chamber at different P supplies (0.1, 0.5, 1, 1.5, 2 mM). Results Both deficient and excessive exogenous P supplies significantly reduced leaf growth, relative chlorophyll concentration and dry matter production in two high-yielding peanut cultivars. The optimum P range was 0.8-1.1 mM for peanut seedlings. Through principal component analysis (PCA) and data fitting, we found that the trade-off of the normalised actual quantum yield [Y(II)] and non-regulatory quantum yield [Y(NO)] in photosystem II (PSII) under light is one of the best proxies to determine the suboptimal, supraoptimal, deficient and toxic P supplies, because they are the two key factors with major positive and negative effects of PC1, accounting for 75.5% of the variability. The suboptimal P range was 0.41-0.8 mM and the supraoptimal P range was 1.1-1.72 mM. The suboptimal P supplies corresponded with a leaf P concentration range of 4.8-8.1 mg P g(-1) DW, while the supraoptimal P supplies corresponded with a leaf P concentration range of 9.9-12.2 mg P g(-1) DW. Conclusions Both deficient and toxic P levels severely inhibited leaf growth and photosynthesis of peanut, and these unfavourable conditions were associated with significant reduction of biomass and photosynthesis, and photodamage extending beyond PSII. The trade-off of the normalised Y(II) and Y(NO) is a useful benchmark to demarcate deficient, suboptimal, supraoptimal and toxic P-fertilisations levels in A. hypogaea.

Keywords

Peanut; Phosphorus; Suboptimal; Supraoptimal; Photosynthesis

Published in

Plant and Soil
2020, Volume: 447, number: 1-2, pages: 99-116

SLU Authors

• Yong, Jean W.H

  • Department of Biosystems and Technology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Plant Biotechnology
Food Science
Agricultural Science


Publication identifier

DOI: https://doi.org/10.1007/s11104-019-04041-w

Permanent link to this page (URI)

https://res.slu.se/id/publ/102037