作 者 ：王贺正 徐国伟 吴金芝 张均 陈明灿 付国占 李友军
期 刊 ：植物营养与肥料学报 2013年 19卷 2期 页码：288-296
Keywords:wheat, nitrogen level, dry matter translocation, grain filling, enzyme activity,
摘 要 ：为了明确不同氮素水平下小麦干物质运转、 籽粒灌浆及有关淀粉酶活性的变化规律，以豫麦49198为材料，在河南科技大学试验农场，通过设置120 kg/hm2（N1）、 180 kg/hm2（N2）、 240 kg/hm2（N3）和300 kg/hm2（N4）4个氮素水平，研究了小麦茎鞘物质运转、 籽粒灌浆和淀粉合成有关酶活性。结果表明，在一定范围内增施氮肥有利于提高茎鞘干物重以及抽穗后茎鞘物质输出量、 输出率、 转化率，各指标均以N3处理最高，N1处理最低。适量增施氮肥能提高籽粒生长潜势、 最大灌浆速率和平均灌浆速率，缩短籽粒生长活跃期，使品种达最大灌浆速率的时间提前，其中N3处理最佳，其最大灌浆速率和平均灌浆速率分别为0.557×10-2 和0.373×10-2 g/(grains·d)，N4处理最差，其最大灌浆速率和平均灌浆速率分别为0.406×10-2 和0.272 ×10-2 g/(grains·d)。适量增施氮肥能增强籽粒灌浆过程中可溶性淀粉合成酶（SSS）、 Q酶和ADPG焦磷酸化酶3种酶活性，各处理中，酶活性均以N3处理最高，N4处理最低，N3和N4处理相比SSS、 Q和ADPG焦磷酸化酶最大酶活性分别提高了22.0%、 23.2%和9.5%。但过量施氮，降低了茎鞘干物重的积累、 运输和转化能力以及籽粒灌浆速率和3种淀粉合成有关酶活性。抽穗期茎鞘干物重、 抽穗后茎鞘干物质输出量和输出率均与籽粒产量呈显著正相关。试验表明，在适宜氮肥水平下小麦具有较高的茎鞘物质输出率和转化率、 籽粒灌浆速率及淀粉合成有关酶活性，是产量较高的生理基础。
Abstract:In order to clarify the effects of different levels of nitrogen on dry matter translocation,grain filling and activities of enzymes involved in starch synthesis of wheat, to improve nitrogen use efficiency, to reduce the effect of excessive application of fertilizer on environment pollution and to increase crop yield, a field experiment was carried out in the experimental farm of Henan University of Science and Technology under different nitrogen treatments,120 kg/ha, 180 kg/ha, 240 kg/ha and 300 kg/ha. The wheat cultivar, Yumai 49-198 was selected for the study. The results indicate that the increase of nitrogen input within a certain extent could increase dry matter weights of stem and sheath at the heading and harvest stages, exporting amount of stems and sheath and export and transform percentages of the matter after the heading. These indexes are highest under the N3 treatment and are lowest under the N1 treatment. Increasing proper nitrogen could improve grain growth potential, the maximum rate of grain filling and mean rate of grain filling, and shorten the active grain-filling period and the time of reaching the maximum grain-filling rate. The N3 treatment is the best, it’s maximum grain filling rate and the average grain filling rate are 0.557×10-2 and 0.373 ×10-2 g/(grains·d), respectively. The N4 treatment is the worst, it’s maximum grain filling rate and the average grain filling rate are 0.406×10-2 and 0.272 ×10-2 g/(grains·d), respectively.Increasing proper nitrogen could increase activities of key enzymes of wheat grain including soluble starch synthase (SSS), ADP glucose pyrophosphorylase (ADPGPPase) and soluble starch branch enzymes during the grain filling. Compared to the N4 treatment, the enzyme activities are the highest under the N3 treatment and are the lowest under the N4 treatment. Maximum enzyme activities of SSS, Q and ADPGPPase under the N3 treatment are increased by 22%, 23.2% and 9.5%. Dry matter weights of stem and sheath at the heading,exporting amounts of stems and sheath, export and transform percentages of the matter after the heading are positively significant or very significant correlation with the grain yield. This experiment shows that higher export and transform percentages of stem and sheath, rate of grain filling and activities of key enzymes of wheat grain are the physiological basis for higher yield under a appropriate nitrogen level.
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