IAA对木薯生长及氮素吸收的影响

Effect of IAA on Growthand Nitrogen Absorption of Cassava

【目的】探究IAA对木薯生长及氮(N)素吸收的影响,为木薯栽培的化学调控研究提供理论依据。【方法】通过盆栽试验,以华南205为材料,分析低N处理94 d条件下外施IAA对木薯形态、干物质量、N含量和N积累量的影响及木薯各部位内源IAA含量的差异。【结果】与对照(低N处理)相比,低N条件下喷施IAA可使木薯株高、各部位N含量及N积累量显著提高; 94 d内,喷施IAA处理使木薯叶面积、总根系表面积及总根长分别增加8. 26%、20. 48%及20. 67%;通过比较木薯各部位内源IAA含量,发现叶面喷施IAA后根尖内源IAA含量下降,茎尖及叶片内源IAA含量显著增加。【结论】低N条件下叶面喷施IAA可显著提高木薯茎尖内源IAA含量,维持顶端优势和叶片代谢强度,促进木薯对N素的吸收以及转运,进而促进干物质累积,加快木薯生长。

【Objective】In order to provide more theoretical support on application of chemical control technology in cassava cultivation,the effect of IAA on growth and nitrogen(N)absorption of cassava was investigated.【Method】The effects of IAA on morphology,dry matter quality,N content and N accumulation and the difference of endogenous IAA content in different parts of cassava(Southern China 205)under low N treatment for 94 days were analyzed by pot experiment.【Result】Compared with CK(Low N without IAA),the plant height,leaf area and the dry matters of cassava sprayed with IAA were increased.At the 94 days of planting,the leaf area,total root surface area and total root length of cassava sprayed with IAA increased by 8.26%,20.48%and 20.67%,respectively.The treatment of sprayed with IAA on leaves induced the increase of the IAA contents in stem tip and leaf and the decrease of the root tip.【Conclusion】Under the low nitrogen condition,spraying IAA on the leaves could significantly increase the endogenous IAA content of the stem tip of cassava,maintain the growth advantage of stem tip and the metabolic intensity of leaves,promote the absorption and transport of cassava to nitrogen,and then promote the accumulation of dry matter and accelerate the growth of cassava.