大量元素胁迫下南瓜化感作用研究

Cucurbita moschata Allelopathy under Macroelement Stress

研究采用水培实验、生物测试及室内分析相结合的方法,研究在不同大量元素N、P、K、Ca、S、Mg营养胁迫下幼苗期南瓜根系分泌物及其提取物对南瓜幼苗生长的化感作用.结果表明:南瓜具有自毒作用,不同大量营养元素胁迫对其胚根和胚芽生长均产生了抑制作用,不同的营养条件对其根系分泌物的影响不同,营养元素的合理搭配可以减轻自身的自毒作用.南瓜根系分泌物经乙酸乙酯提取的活性有机物对南瓜胚根生长亦表现出抑制作用,且抑制作用程度较大.南瓜幼苗期根系干物质水浸液中存在着抑制南瓜幼苗生长的化感物质.筛选出南瓜根系分泌物对自身幼苗生长产生抑制作用最弱的大量元素水平优化组合,为南瓜的营养胁迫机理提供依据.

The experiment adopted hydroponic culture, biological testing and lab determination to study alleopathic effects of root exudates and extracts of Cucurbita moschata M. seedlings under the stresses of different macro elements (N, P, K, Ca, S, Mg) on Cucurbita moschata M. seedlings. The results showed that Cucurbita moschata M. had autotoxicity and the stresses of different macroelements had inhibiting effects on the growths of its radicals and plumule, different nutritious conditions exerted different impacts on its root exudates and the proper combination of nutritious elements could alleviate its autotoxicity. Organic substances extracted with ethyl acetate from the exudates of Cucurbita moschata M. roots also showed inhibiting effects on the growth of Cucurbita moschata M. radicals but to a higher extent. There existed allelopathic substances in water extracted solutions of the roots taken at the seedling stage, which inhibited the growth of Cucurbita moschata M.seedlings. Screening the optimal macroelement combination at which the exudates of Cucurbita moschata M. roots showed the least inhabitable effect on the growth of its seedling would provide the basis for Cucurbita moschata M. mechanism in response to nutrition stresses.