不同氮肥运筹对超高产小麦NR活性和产量影响的研究

Effects of Different Nitrogen Operations on Nitrate Reductase Activity and Yield of High-Yielding Wheat

通过三种氮肥处理试验,研究了氮肥运筹对各生育期NR活性及产量、产量性状的影响,阐述了NR活性与产量和产量性状的关系。结果表明:从分蘖期始,小麦叶片NR活性表现出逐渐上升的趋势,至开花期达到最高,其后又逐渐下降。不同氮肥处理的NR活性在分蘖至孕穗差异不大,在孕穗之后,氮肥一次底施的处理一的NR活性明显低于药隔期追施的处理二和处理三。药隔期追施氮肥可明显促进成穗数、穗长、结实小穗数、穗粒数、千粒重、穗粒重等产量性状的增加,对提高产量具有重要作用。对两种类型品种,普通型的豫麦41号宜采用药隔期重施追肥,而大粒型的兰考86(79)则以药隔期补施氮较好。NR活性与产量、产量性状的相关关系,在分蘖至拔节期间表现不密切,但孕穗至成熟期间与产量的相关系数均达高度正相关,与穗粒数、穗粒重的相关关系也较为密切,反映出通过药隔期追施氮肥,增加小麦中后期NR活性对提高产量是非常重要的。

The effects of nitrogen operation on nitrate reductase (NR) activity during growth development period and yield, yield components of wheat and relationship between NR activity and yield, yield components were investigated in the experiments of three nitrogen treat ments. The results are shown as follows: during wheat growth development period, there was a tendency that NR activity in leaf increased gradually from tillering stage, reached maximum at blossom, decreasing by degrees afterwards. The difference of NR activity among nitrogen treat ments was small from tillering to booting, but after booting NR activity of treatment 1 (100% nitrogen applied before sowing) wss obviously lower than that of treatment 2 (20% nitrogen ap plied at anther connective stage) and treatment 3 (40% nitrogen applied at anther connective stage). Nitrogen dressing at anther connective stage increased spike number, spike length, spikelet bearing number, grain number per spike, 1000 grain weight, grain weight per spike and had an important role in increasing yield. Heavy nitrogen dressing at anther connective stage was suitable for Yumai No. 41 which belongs to comman type, and additional nitrogen dressing at an ther connective stage was suitable for Lankao 86(79) which belongs big grain type. NR acitivity from tillering to jointing wasn't closely related to yield and yiled components. The correlation-co efficients betweent NR activity after booting and yield, grain number per spike, grain weight per spike were all positive. This showed that improving NR activity by nitrogen dressing at anther connective stage was important to increase the yield.