【摘要】 【目的】明确‘凤丹’牡丹不同发育阶段的化学计量特征和分配规律,探讨源-库关系,可为解析其产量构成机制奠定基础,也为油用牡丹的栽培管理提供指导。【方法】采取破坏性取样策略,研究‘凤丹’牡丹年周期中,4、6、8龄(4年生、6年生、8年生)植株的根、茎、叶、花、果等器官中C、N、P元素和可溶性糖含量的变化动态。【结果】1)各器官中C含量的季节性变化趋势相似,且C含量随株龄增大而增高;根和茎中N含量随季节变化的趋势相似,都随株龄增大而上升,不同株龄植株的叶片的N含量变化趋势一致,均在花期最高; P元素含量及其变化在各器官及不同株龄之间存在差异。2)年周期中各器官的C∶N均表现为先升后降,株龄效应明显; C∶P在各器官中变化趋势不一,根和茎的C∶P表现为6年生> 8年生> 4年生,不同株龄叶片的C∶P仅在花期不同(4年生<6年生<8年生),繁殖器官的C∶P表现为4年生<6年生<8年生;年周期中,‘凤丹’N∶P逐渐下降,各器官的N∶P均表现为6年生>4年生>8年生,N∶P变化范围为2. 71～7. 62。3)在休眠期和落叶期,各元素基本上都平均分配到根和茎中,在花期和果熟期,C元素均匀分配到各器官,而N、P元素则较多分配到叶和繁殖器官,株龄对各元素分配动态的影响不一致。4)各器官可溶性糖含量差异明显。以可溶性糖含量表征的源、库强度及源/库比的分析结果显示,初始(休眠期)源结构为根和茎,之后(花果期)的源结构是叶片,库结构则包括花或果实、以及根和茎; 6年生植株的源强度最大,8年生植株则库强度最大,花期源/库比最高的是6年生植株,果熟期则是4年生植株。【结论】‘凤丹’牡丹的化学计量特征和源-库结构关系随生长发育阶段而动态变化,且明显受株龄的影响; N元素是‘凤丹’牡丹生长的限制因子,适当增施N肥可提高产量。更多还原

【Abstract】 【Objective】 ‘Fengdan’(Paeonia ostii) is a new woody oil crop. It is not clear about the carbon,nitrogen,and phosphorus stoichiometry and source-sink structure in this plant species. This study compared the seasonal variations of C,N,P,and soluble sugar concentrations and allocations,as well as the ratios of C ∶N,C ∶P and N ∶P in different organs of ‘Fengdan’in an annual cycle at different stages of development,in order to lay a foundation for the analysis of its yield composition and provide a guidance for the cultivation and management of oil peony. 【Method】A destructive strategy was applied to sample roots,stems,leaves,flowers and fruits of 4-,6-,and 8-year-old plants from Tongling peony garden in Anhui Province at the stage of bud dormancy,flowering,fruit mature,and defoliation. The dynamic changes of C,N,P and soluble sugar concentrations in those samples were measured,and then the allocation and stoichiometry dynamics were analyzed.【Result】The results showed that: 1) all organs had a similar seasonal dynamics of C content,and it increased with tree age. N content in roots and stems had a similar seasonal variation,and it also increased with tree age. Whereas N contents in leaves of different plant ages had a similar changing trend,and it reached the highest values at flowering stage.There were differences in P concentrations in both different organs and different plant ages. 2) The C ∶ N ratio in all Fengdan organs increased first and then decreased in the annual cycle,which was significantly influenced by tree age. The change trend of C ∶P ratio over seasons in all organs was different. The C ∶P ratio in roots and stems was 6 a>8 a>4 a. The C ∶P ratio in leaves presented difference only at flowering stage,with 4 a<6 a<8 a. The C ∶P ratio of reproductive organs was 6 a>8 a > 4 a. In the annual cycle,the N ∶P ratio of ‘Fengdan’decreased gradually. The N ∶P ratio in all organs ranged from 2.71 to 7.62,and was 6 a>4 a>8 a. 3) At dormancy and defoliation stages,C,N,and P were all equally allocated to root and stem. At flowering and fruit mature stages,C was evenly portioned to each organ,whereas N and P were relatively more distributed in leaves and reproductive organs. The effects of plant age on the element allocations were different among C,N and P. 4) There was significantly difference in soluble sugar concentration among different organs.Soluble sugar concentration in source or sink structure was used to indirectly express the source or sink strength,and then to estimate the ratio of source: sink. At the beginning of annual cycle(at dormancy stage),the source structure was root and stem,and it was leaf at flowering and fruiting stages when reproductive organs(flower or fruits) were the main sink structure. At the same time the sink structure included root and stem,as well as flower and fruit. Six-year-old plants had the biggest source strength and eight-year-old plants had the biggest sink strength. Six-year-old plants had the highest source: sink ratio at flowering stage,whereas 4-year-old plants had the highest source: sink ratio at fruiting stage.【Conclusion】Stoichiometry and source-sink structure of‘Fengdan’varied with plant development and growth stages,and were influenced by tree age. N was a limiting factor for plant growth in‘Fengdan’,and appropriate addition of N was able to increase seed yield of oil peony.更多还原