3个木薯主栽品种对氮浓度梯度的响应

Responses of Three Cassava Cultivated Varieties to Gradient Concentrations of Nitrogen

为研究木薯品种之间的耐低氮能力差异,笔者通过土培盆栽实验,对3个国内推广面积较大的主栽品种NZ199,KU50和SC8进行了由低到高的氮浓度梯度胁迫处理,结果显示,在设定的氮梯度下培养1个月后,同一品种的不同氮水平间及同一氮水平的不同品种间在叶片颜色上具有较好的区分度,氮水平显著影响木薯植株的株高,且以株高在低氮和正常氮之间的比值为氮效率系数,可区分这3个品种的耐低氮能力。进一步通过氮水平和株高拟合了氮肥效应函数,二元方程的系数显示这3个品种的耐低氮能力由高到低的顺序是NZ199>KU50>SC8。

To elucidate the nitrogen use efficiency of different cassava varieties, soil pot culture was conducted to differentiate three main cultivars： NZ199, KUS0 and SC8 in China. The three cassava varieties subjected to nitrogen treatments at 4 gradient concentrations from low to normal. The results showed that one month after cultivation the cassava leaf colors are obviously different among the same variety under different nitrogen levels or different varieties under the same nitrogen level. Nitrogen levels have significant impact on cassava plant height, and the ratio of plant height under low nitrogen to that under normal nitrogen can be used as the nitrogen use effi- ciency coefficient to differentiate nitrogen utilization ability of cassava varieties. Further fertilizer response function was obtained by using nitrogen levels and plant height, and the coefficient of this function shows that these cassava varieties are tolerant to low nitrogen in the order of NZ199 〉 KU50 〉 SC8.