中国农业科学 ›› 2017, Vol. 50 ›› Issue (14): 2706-2716.doi: 10.3864/j.issn.0578-1752.2017.14.007

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

氮钾配施对甘薯光合产物积累及分配的影响

汪顺义,刘庆,史衍玺,李欢   

  1. 青岛农业大学资源与环境学院,山东青岛 266109
  • 收稿日期:2016-11-04 出版日期:2017-07-16 发布日期:2017-07-16
  • 通讯作者: 李欢,E-mail:lihuancomcomcom@163.com
  • 作者简介:汪顺义,E-mail:644393504@qq.com
  • 基金资助:
    国家现代农业产业技术体系建设专项(CARS-11-B-14)、国家自然科学青年基金(41501271)

Interactive Effects of Nitrogen and Potassium on Photosynthesis Product Distribution and Accumulation of Sweet Potato

WANG ShunYi, LIU Qing, SHI YanXi, LI Huan   

  1. College of Resources and Environmental Science, Qingdao Agricultural University, Qingdao 266109, Shandong
  • Received:2016-11-04 Online:2017-07-16 Published:2017-07-16

摘要: 【目的】探讨氮钾配施对甘薯光合产物转移分配的影响及其生理机制。【方法】开展两年田间试验,设CK(不施肥)、单独施氮(75 kg N·hm-2)、单独施钾(150 kg K2O·hm-2)和氮钾配施(75 kg N·hm-2+ 150 kg K2O·hm-2)4个处理,在生长前期(40 d)和薯块膨大期(100 d)分别进行13C叶片标记。测定了功能叶13C积累量和分配率、蔗糖合成酶(SS)和磷酸蔗糖合成酶(SPS)活性、叶绿素荧光和光合特性、干物质积累和产量等指标,并进行逐步回归分析、通径分析和RDA分析。【结果】与单独施氮和单独施钾相比,氮钾配施处理2014和2015年分别增产7.9%—10.1%和9.3%—10.7%。双因素分析表明,氮钾配施对甘薯产量的增加呈显著的正交互效应,其中,2014年交互效应值为0.95 t·hm-2,2015年交互效应值为1.35 t·hm-2。在生长前期和薯块膨大期,与氮、钾处理相比,氮钾配施处理显著提高了甘薯功能叶光合及叶绿素荧光特性,从而促进了两关键生长期光合产物的积累。其中CO2同化速率对应的量子产额(ΦCO2)提高27.1%—39.7%,净光合速率(Pn)提高9.1%—20.2%,甘薯地上部和地下部13C总积累量提高26.3%—42.2%。氮钾配施条件下光合产物分配在两生长期内存在差异。生长前期,氮钾配施处理通过提高叶片SS和SPS酶活性,显著提高了地上部13C分配率(达60.7%)(P<0.05),促进光合产物在源器官分配;薯块膨大期,氮钾配施处理显著提高块根中SS和SPS酶活性,光合产物在库-源器官膨压差的作用下由地上部向地下部转运,显著提高13C向块根分配(13C分配率为71.6%,P<0.05)。逐步回归分析表明,SS和SPS酶活性、光合特性和叶绿素荧光特性是调控甘薯光合产物分配的关键指标(R1=0.954,R2=0.912);通径分析表明,生长前期氮钾配施对甘薯13C分配的影响直接作用系数较大的是PnFv/Fm和SS;薯块膨大期氮钾配施对甘薯13C分配的影响直接作用系数较大的是PnΦPSⅡ和SPS。【结论】生长前期,氮钾配施处理通过提高PnFv/Fm和SS促进光合产物在地上部积累,实现“建源”,而薯块膨大期主要提高Pn、ΦPSⅡ和SPS促进光合产物由地上部向地下部转运,兼顾“促流”和“扩库”,氮钾协同最终提高了甘薯产量。

关键词: 甘薯, 光合特性, 叶绿素荧光, 13C分配, 酶活性

Abstract: Objective】The objective of this paper is to explore the interactive effects of nitrogen and potassium on photosynthesis product transfer allocation and its physiological mechanism of sweet potato.【MethodThe two years field experiments include four treatments: CK, N, K and N+K, 13C blade tag on leaves was made on 40 d and 100 d after transplanting. The interactive effects of nitrogen and potassium on 13C distribution, photosynthetic characteristics, fluorescence characteristic, SS activities, SPS activities, and yield of sweet potato were studied. 【Result】Compared with N, K, interactions of N and K treatment, in 2014, yield increased by 10.1% and 7.9%, and the interactive effect value was 0.95 t·hm-2; in 2015, yield increased by 10.7% and 9.3%, and the interactive effect value was 1.35t·hm-2. Compared with N and K treatments, interactions of N and K treatment improved the functional leaf photosynthesis and chlorophyll fluorescence characteristics, and the accumulation of photosynthetic products increased at two key stages of sweet potato. For example, ΦCO2increased by 27.1%-39.7%, Pn increased by 9.1%-20.2%, and 13C total accumulation increased by 26.3%-42.2%. At the early stage of growth, nitrogen and potassium interactions treatment significantly increased leaf SS and SPS enzyme activities, their activities were significantly higher than that in root, and significantly improved the 13C distribution rate in leaves by 60.7%, promoted photosynthetic products distribution in the source organ. In root rapid expansion period, interactions of N+K treatment significantly increased the SS and SPS enzyme activities of root, which were significantly higher than that of leaf blade, photosynthetic product distributed from the ground to the underground part under the action of pressure in the sink - source organs, nitrogen and potassium interactions increased the 13C distribution rate in root by 71.6%. Stepwise regression analysis showed that the carbon metabolism enzyme photosynthetic characteristics and chlorophyll fluorescence characteristics are the key indicators of product distribution of sweet potato(R1=0.954, R2=0.912). Path analysis indicated that the largest coefficients affected 13C distribution under nitrogen and potassium interaction were Pn, Fv/Fm and SS at the early stage of growth while key coefficients affected 13C distribution were Pn, ΦPSⅡ and SPS in root rapid expansion period. 【Conclusion】It was concluded that nitrogen and potassium interaction promoted the accumulation of photosynthetic products in aerial part through increase of Pn, ΦPSⅡ and SS, thus realized the construction of source at the early stage of growth. In root rapid expansion period, N and K interaction mainly improved Pn, ΦPS and SPS and thus promoted the transfer of photosynthetic products from the ground to the underground part and promoted the yield of sweet potato.

Key words: sweet potato, photosynthetic characteristics;chlorophyll fluorescence, 13C distribution, enzyme activities