施氮深度和水分胁迫对藜麦幼苗生理及产量的影响

Effects of nitrogen fertilization depth and water stress on quinoa seedling physiological characteristics and yield

关键词:  藜麦, 水分胁迫, 施肥深度, 控释尿素, 幼苗形态发育, 幼苗生理特性, 产量

Key words:  Chenopodium quinoa, water stress, fertilization depth, controlled-release urea(CRU), morphological development of seedling, physiological characteristics of seedling, yield

摘要:

为了探讨藜麦应对施肥深度和水分胁迫的响应,该文以藜麦(Chenopodium quinoa)为材料,在盆栽条件下,设置3种施氮处理[D1(控释尿素施在0～8 cm深度)、D2(控释尿素施在8～16 cm深度)、D3(控释尿素施在16～24 cm深度)]和3种水分处理[W1(正常供水)、W2(中度干旱)、W3(重度干旱)],分析施氮深度和水分胁迫对藜麦幼苗生理及产量的影响。结果表明:(1)相同水分条件下,随着施肥深度的增加,藜麦生长指标(株高、茎粗、叶面积、地上部生物量、主根长、根系表面积、根系体积)、生理指标 [超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、可溶性糖含量、可溶性蛋白含量、叶绿素总量]和产量指标呈先升高后降低趋势。D2处理(适当的深施氮肥)均高于D1处理(浅层施氮)和D3处理(底层施氮)。(2)相同施氮深度条件下,随着干旱胁迫程度的增加,藜麦生长指标和产量指标呈逐渐降低的趋势,生理指标均呈先升高后降低的趋势。说明藜麦幼苗对水分需求明显,可通过增加抗氧化酶活性和渗透调节物质适应一定程度的干旱,生产实践中应注意苗期水分的供应,以促进生育后期产量的形成。综上可知,适宜的水氮管理(D2W1)可以促进藜麦的生长及生理特性,增强藜麦的抗旱能力,提高藜麦的产量。该研究结果为进一步研究藜麦的水肥管理、高产栽培提供参考。

Abstract:

To explore the response mechanism of quinoa(Chenopodium quinoa)to fertilization depth and water stress. Quinoa in pots were used as materials to set three nitrogen fertilization treatments [D1, placement of controlled-release urea(CRU)at 0-8 cm depth; D2, placement of CRU at 8-16 cm depth; D3, placement of CRU at 16-24 cm depth] and three kinds of water treatments(W1, normal moisture; W2, moderate drought; W3, severe drought)to discuss the effects of quinoa seedling physiological characteristics and yield. The results were as follows:(1)Under the same water condition, with the increase of fertilization depth, the growth indexes(plant height, stem diameter, leaf area, aboveground biomass, length of main root, surface area of root, root volume), physiological indexes [superoxide(SOD)activity, peroxidase(POD)activity, catalase(CAT)activity, soluble sugar content, soluble protein content, and the total chlorophyll content] and yield index tended to increase initially and then decrease. D2 treatment(appropriate deep nitrogen fertilization)was higher than D1(shallow deep nitrogen fertilization)and D3 treatment(bottom deep nitrogen fertilization).(2)Under the same nitrogen fertilization depth, with the increase of drought stress, the growth indexes and yield index of quinoa decreased gradually, and the physiological indexes were rising firstly and then decreasing. It was suggested that the water demand of quinoa seedlings was obvious, which could adapt to drought to some extent by increasing antioxidant enzyme activities and osmotic regulating substances. In practice, attention should be paid to the supply of water in seedling stage to promote the formation of yield in the later stage of growth. In conclusion, suitable water and nitrogen management(D2W1)can promote the growth and physiological characteristics of quinoa, and enhance the drought resistance of quinoa and improve the yield of quinoa. The results of this study provide a reference for further study on water and fertilization management and high yield cultivation of quinoa.