摘要： 为阐明氮、钾营养及其交互作用对甘薯分根结薯期根系分化及叶片酶活性的影响,采用砂培研究方法,设氮钾正常供给(正常)、多氮(N)、多钾(K)和氮钾配施(NK)4个处理。探讨了氮、钾及其交互作用对甘薯苗期养分吸收、农艺学性状、根系发育、硝酸还原酶(NR)、蔗糖合成酶(SS)、蔗糖磷酸合成酶(SPS)和腺苷二磷酸焦磷酸化酶(ADPGPPase)的影响。结果表明,与氮钾正常供给处理相比,N处理显著提高了甘薯地上和地下部氮吸收量、SPAD值、叶片数、叶面积;N处理总根长、根表面积、根体积、平均直径和NR活性、SS活性和SPS活性分别提高了5.9%,12.1%,1.9%,3.6%,14.1%,13.6%,19.5%,而ADPGPPase活性降低了7.1%;另外N处理块根比例减少7.9%,中等根(徒耗养分的根)分化比例升高7.7%。与氮钾正常供给处理相比,K处理显著提高了地上和地下部氮吸收量,且K处理根系活力、总根长、根表面积、根体积、根平均直径、SS活性、SPS活性、ADPGPPase活性分别提高了16.2%,28.2%,10.1%,39.3%,12.6%,14.9%,20.1%,14.5%;氮钾配施(NK)处理须根和块根分化比例升高0.2%和12.4%,中等根(徒耗养分的根)分化比例降低12.6%。与N和 K处理相比,氮钾配施(NK)处理能够调控甘薯苗期地上和地下部生物量比例(T/R值),同时提高须根和块根分化比例,显著促进了薯块的膨大。双因素分析表明,氮钾配施(NK)对地上和地下部氮钾含量、根系活力、根平均直径、NR活性、SPS活性、ADPGPPase活性均存在显著的正交互效应。从地下部根系形态和地上部酶学变化两方面揭示氮钾交互机制,为甘薯高产优质栽培提供理论依据。

关键词: 甘薯, 氮钾交互, 根系, 酶活性

Abstract: In order to clarify the mechanism of nitrogen,potassium and their interactions on sweet potato growth,we utilized sand culture methods and made four treatments:CK,N,K and NK and explored the effects of nitrogen,potassium and their interactions on nutrients uptake,agronomic traits,root development,NR,SS,SPS and ADPGPPase of sweet potato.The results showed that N treatment significantly increased the shoot and root nitrogen content;SPAD value,leaf number,leaf area of sweet potato; total root length,root surface area,root average diameter and root volume,NR activity,SS activity and SPS activity were 5.9%,12.1%,1.9%,3.6%,14.1%,13.6% and 19.5% higher in N treated plants than in CK plants;ADPGPPase activity in N treated plants was 7.1% lower than in CK plants.Compared with CK,N treatment's tubers rates were decreased by 7.9%,while the proportion of middle-root (root only waste nutrients) was increased by 7.7%.Compared with CK,K treatment significantly increased the shoot and root potassium content,root activity,total root length,root surface area,root volume and root mean diameter,SS activity,SPS activity,ADPGPPase activity were increased by 16.2%,28.2%,10.1%,39.3%,12.6%,14.9%,20.1% and 14.5%.Compared with CK,K treatment's fibrous roots and tubers were increased by 0.2% and 12.4%;while the proportion of middle-root was decreased by 12.6%.Compared with N and K treatments,respectively,NK had interactive effects on the growth of shoot and root of the sweet potato and increased the proportion of fibrous roots and tubers,significantly promoted the tuber formation.The table of two-factor analysis showed that NK treatment exist significant positive interaction effects on shoot and root nitrogen and potassium content,root activity,root diameter,NR activity,SPS activity,ADPGPPase activity.The results revealed the interaction mechanisms of nitrogen and potassium from the root morphology and shoots two enzyme changed and provided a theoretical basis for high yield and quality of sweet potato cultivation.

Key words: Sweet potato, Nitrogen and potassium interaction, Root morphology, Enzyme activities

中图分类号: 

• S531