甜菜对低氮胁迫的形态学响应机制

The Morphological Response Mechanism of Sugar Beet to Low Nitrogen Stress

为了分析甜菜对低氮胁迫在形态学上的应答机制,本研究以甜菜种质资源‘780016B/12优’为研究对象,对缺氮(N 0 mmol/L)和低氮(N 1.5 mmol/L)条件下甜菜植株的形态和根系构型变化进行了深入分析。结果表明,甜菜遭受氮胁迫时,地上部生物量积累减少,地下部生物量积累增加,根冠比增加,叶面积减少,甜菜生长发育受到抑制。低氮胁迫7~14天后的根系面积、体积和根系分叉数增加量均大于对照(N 10 mmol/L)。氮胁迫下,甜菜的根系构型呈二分体状,且随着胁迫时间和缺氮程度的增加,地下生物量越大,这种状况表现的越为明显。因此可以推断,甜菜植株根系生物量的高低与根系构型有着密切的联系,甜菜通过改变根系比例和根系构型来获得氮素平衡。

In order to analyze the morphological response mechanism of sugar beet to low-nitrogen stress,sugar beet germplasm resource‘780016B/12 superior’was used as the research material,the changes of morphology and root architecture of sugar beet were comprehensively analyzed under nitrogen deficiency(N 0 mmol/L)and low nitrogen(N 1.5 mmol/L).The results showed that under nitrogen stress,the above-ground biomass accumulation decreased,the underground biomass accumulation increased,the root to shoot ratio increased,the leaf area decreased,and the growth and development of sugar beet was inhibited.After 7 to 14 days of low nitrogen stress,the increase of root area,volume and root branch number were greater than those of the control(N 10 mmol/L).Under nitrogen stress,the root architecture of sugar beet was dichotomy,and with the increase of stress time and nitrogen deficiency,the greater the underground biomass,the more obvious this phenomenon is.Therefore,it can be inferred that the root biomass of sugar beet is closely related to the root architecture.Sugar beet obtains nitrogen balance by changing the root ratio and root architecture.