不同氮水平下小麦植株的碳氮代谢及碳代谢与赤霉病的关系

Effect of nitrogen application on carbon and nitrogen metabolisms and relationship between carbon metabolism and wheat scab

为明确不同施氮量下小麦植株的碳氮代谢特性及碳代谢与小麦赤霉病的关系，本文采用田间小区试验，以小麦多穗型品种‘豫麦49．198’和大穗型品种‘周麦16’为供试材料，在0kg（N）·hm^-2、120kg（N）·hm^-2、180kg（N）·hm^-2、240kg（N）·hm^-2、360kg（N）．hm125个氮肥水平下，探讨了不同施氮水平对小麦植株可溶性糖含量、C／N以及小麦赤霉病发病率和病情指数的影响。结果表明：两个品种小麦植株内的可溶性糖含量和C／N由越冬到开花期呈“V”形变化，拔节期最低，分别为80～200mg．g^-1和3～10。开花期各处理间差异达到最大，且施氮处理植株的可溶性糖含量和C／N比不施氮处理分别低15．4％～47．7％和24．5％～63．1％。植株全氮含量随施氮量的增加而增加，各处理在小麦拔节期和开花期差异最大。两个品种小麦植株的可溶性糖和氮素的累积吸收量在小麦生育期内均呈增加趋势。相关分析表明，植株全氮含量与小麦的可溶性糖含量在小麦拔节期和开花期显著负相关；小麦拔节期和开花期的可溶性糖含量、C／N与小麦赤霉病的发病率和病情指数呈线性关系。说明小麦拔节期到开花期的碳氮代谢对赤霉病的发生影响较大。

To clarify the characteristics of carbon and nitrogen metabolism in wheat plants under different nitrogen applica- tion and the relationship between carbon metabolism and wheat scab, a field experiment was conducted in Yuzhou County of Henan Province using 5 nitrogen rates of 0 kg（N）·hm^-2, 120 kg（N）·hm^-2, 180 kg（N）·hm^-2, 240 kg（N）·hm^-2, 360 kg（N）·hm^-2 and two winter wheat genotypes of multi-spike cultivar ＇Yumai49-198＇ （YM49-198） and big spike variety ＇Zhoumail6＇ （ZM16）. The results indicated that the soluble sugar content and C/N from wintering to flowering stages showed a ＂V＂ type, and was lowest at jointing stage, with the lowest values of 80-200 mg.g^-1 and 3-10, respectively, for two cultivars. The maximum differences among different treatments appeared at flowering stage, when the soluble sugar content and C/N of nitrogen treat- ments were 15.4%-47.7%, 24.5%-63.1%, respectively, lower than those of the non nitrogen treatment. The total nitrogen content increased with the increase of nitrogen application rate, and difference among treatments reached the maximum at jointing and flowering stages. The accumulation of soluble sugar and nitrogen showed an increasing trend. Correlation analysis showed that the total nitrogen content at jointing and flowering stages were significantly negatively correlated with soluble sugar content. The soluble sugar content, C/N at jointing and flowering stages showed a linear relationship with wheat scab incidence and disease index. This indicated that the carbon and nitrogen metabolism from jointing to flowering stages had a greater impact on the scab of wheat.