Li Hai-Gang;Shen Jian-Bo;Zhang Fu-Suo;Lambers Hans
期刊论文
10.1093/aob/mcq012
SCI
Annals of Botany
9
105#4
2010//
英文
585-593
585-593
Background and Aims Phosphorus (P) is a major factor controlling cluster-root formation. Cluster-root proliferation tends to concentrate in organic matter (OM)-rich surface-soil layers, but the nature of this response of cluster-root formation to OM is not clear. Cluster-root proliferation in response to localized application of OM was characterized in Lupinus albus (white lupin) grown in stratified soil columns to test if the stimulating effect of OM on cluster-root formation was due to (a) P release from breakdown of OM; (b) a decrease in soil density; or (c) effects of micro-organisms other than releasing P from OM.
Methods Lupin plants were grown in three-layer stratified soil columns where P was applied at 0 or 330 mg P kg 21 to create a P-deficient or P-sufficient background, and OM, phytate mixed with OM, or perlite was applied to the top or middle layers with or without sterilization.
Key Results Non-sterile OM stimulated cluster-root proliferation and root length, and this effect became greater when phytate was supplied in the presence of OM. Both sterile OM and perlite significantly decreased cluster-root formation in the localized layers. The OM position did not change the proportion of total cluster roots to total roots in dry biomass among no-P treatments, but more cluster roots were concentrated in the OM layers with a decreased proportion in other places.
Conclusions Localized application of non-sterile OM or phytate plus OM stimulated cluster-root proliferation of L. albus in the localized layers. This effect is predominantly accounted for by P release from breakdown of OM or phytate, but not due to a change in soil density associated with OM. No evidence was found for effects of microorganisms in OM other than those responsible for P release.
Citrate exudation; cluster-root formation; root proliferation; Lupinus albus; phosphorus; soil patch; soil micro-organisms; soil organic matter
作物高效利用养分资源的根际调控机理