Metabolite profiling of Komatsuna (Brassica rapa L.) field-grown under different soil organic amendment and fertilization regimes.

摘要

Among agricultural soil fertility management options, the environmental benefits of organic amendments have recently drawn particular attention. However, little information exists about their effects on crop metabolites or quality. Field plots of Komatsuna (Brassica rapa L. var. perviridis) were planted in a fractional factorial design with the following treatments: soil amendments of cattle manure (0, 2 or 4 kg m-2), wheat straw (0, 0.05 or 0.1 kg m-2), fast release nitrogen (N) (0, 6 or 12 g N m-2 of ammonium sulfate), slow release N (0, 3 or 6 g N m-2 of coated ammonium nitrate), phosphorus (P) [0, 5 or 10 g phosphorus pentoxide (P₂O₅) m-2 of lime superphosphate] and potassium (K) [0, 6 and 12 g potassium oxide (K₂O) m-2 as potassium sulfate]. Metabolite profiling was carried out using a gas chromatograph/mass spectrometer (GC/MS), which yielded 62 and 67 metabolites in the leaves and the petioles, respectively. Metabolite peak areas were subjected to principal component analysis (PCA). The first component accounted for 44.1% of the total variance and bore a close relationship to N. The third component accounted for 8.8% of the total variance and was used to distinguish between different levels of manure application. An analysis of variance (ANOVA) of treatment factor effects on individual metabolites showed that the three most significant factors, from highest to lowest, were N absorption, manure amendments and slow release N. The effects of the manure amendments were not fully explained by its attendant N, P or K inputs. This result raises the question as to what mechanisms may bring about the metabolic changes caused by the manure amendment. The current findings will serve to direct further studies on the relationship between crop quality and cultivation procedures and will lead to more efficient quality control methods.