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Plant function and evolutionary biology
RESEARCH ARTICLE

Multivariate associations of flavonoid and biomass accumulation in white clover (Trifolium repens) under drought

Wouter L. Ballizany A C , Rainer W. Hofmann A , M. Z. Zulfiqhar Jahufer B and Brent A. Barrett B
+ Author Affiliations
- Author Affiliations

A Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 84, Lincoln 7608, New Zealand.

B AgResearch Grasslands Research Centre, PO Box 11008, Palmerston North 4442, New Zealand.

C Corresponding author. Email: wouter.ballizany@gmail.com

Functional Plant Biology 39(2) 167-177 https://doi.org/10.1071/FP11193
Submitted: 29 August 2011  Accepted: 25 November 2011   Published: 18 January 2012

Abstract

White clover (Trifolium repens L.) is an important pasture legume in temperate regions, but growth is often strongly reduced under summer drought. Cloned individuals from a full-sib progeny of a pair cross between two phenotypically distinct white clover populations were exposed to water deficit in pots under outdoor conditions for 9 weeks, while control pots were maintained at field capacity. Water deficit decreased leaf water potential by more than 50% overall, but increased the levels of the flavonol glycosides of quercetin (Q) and the ratio of quercetin and kaempferol glycosides (QKR) by 111% and by 90%, respectively. Water deficit reduced dry matter (DM) by 21%, with the most productive genotypes in the controls showing the greatest proportional reduction. The full-sib progeny displayed a significant increase in the root : shoot ratio by 53% under water deficit. Drought-induced changes in plant morphology were associated with changes in Q, but not kaempferol (K) glycosides. The genotypes with high QKR levels reduced their DM production least under water deficit and increased their Q glycoside levels and QKR most. These data show, at the individual genotype level, that increased Q glycoside accumulation in response to water deficit stress can be positively associated with retaining higher levels of DM production.

Additional keywords: abiotic stress, kaempferol, quercetin, secondary metabolism.


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