摘要
利用冬小麦品种‘鲁麦 2 2’(Triticumaestivumcv .‘Lumai 2 2’)在大田条件下研究了钾素对小麦旗叶蔗糖和籽粒淀粉积累及其有关酶活性的影响。结果表明 ,钾素有利于提高旗叶光合速率 ,增强开花后旗叶磷酸蔗糖合成酶活性 ,提高旗叶中蔗糖的含量 ;从而提高了灌浆期间籽粒中蔗糖的供应 ,增强了籽粒中蔗糖合成酶和腺苷二磷酸葡萄糖焦磷酸化酶的活性 ,加速了淀粉积累速率 。
There has been a phenomenon in wheat production of attaching importanc e to nitrogen fertilizer but ignoring potassium fertilizer. Employing nitrogen f ertilizer solely results in excessively growing, soft stemmed, wheat, leading to a reduction in kernel yield. Also, the soil hardens and the environment is dest royed. As one of the indispensable elements, potassium has become an important l imiting factor in wheat kernel yield increasing. This article studied the effect of potassium on photosynthetic rate, sucrose content, activity of sucrose_phosp hate synthase (SPS)-the key enzyme in sucrose synthesis-in flag leaves, and on the sucrose content, activity of sucrose synthase (SS) (the key enzyme in suc rose decomposition), activity of adenosine diphosphorate glucose pyrophrylase (A DPGPPase) (the key enzyme in starch formation), and starch accumulation rate of kernels of wheat. The study was carried out in 1999 on an experimental farm of S handong Agricultural University, Taian, China, using the variety `Lumai 22' whic h has high yield potential. The experiment set three potassium treatments (K 0, K 1 and K 2); the potassium amounts supplied were 0 kg K 2O, 168.75 kg K 2O, 225.00 kg K 2O per hm 2 respectively, using KCl as the potassium fertilizer. E ach treatment had three replicates. The plot area was 2 m×6 m=12 m 2, with sowing on October 11 i n 1999. The basic seedling number was 120 per m 2. Single stems flowering on t he same day were selected and marked using hanging cards during the anthesis perio d. These marked stems were used as the sample. The results suggest that potassiu m can prolong the peak period of photosynthetic rate, increase the supply of pho tosynthetic products in flag leaves, improve the activity of SPS after anthesis, accelerate sucrose synthesis during the early and middle periods of kernel fill ing in flag leaves, and increase sucrose content in flag leaves. Potassium also enhanced the supply of sucrose in the kernel during kernel filling, increased th e activity of SS which favors sucrose decomposition in the kernel, and produces sufficient precursor for starch synthesis; improved the activity of ADPGPPase wh ich favors starch formation; accelerated the rate of starch accumulation during the peak period of starch synthesis, and finally increased spike number, kernel weight and yield in wheat. Among the three treatments, each index had the greate st value in the K 1 treatment. So the K 1 treatment produced the highest kerne l yield. The physiological effects of potassium on yield in wheat were discussed from two points of view, namely, from the point of photosynthetic product supplying inte nsity in flag leaves and precursor supplying intensity in kernel sink, concentra ting on key enzymes. It was considered that potassium could increase kernel weig ht and yield by increasing the activity of SPS in the flag leaf and increasing t he activities of SS and ADPGPPase in the kernel, but the physiological and bioch emical mechanisms underlying this action should be investigated further. Further more, this article also discussed the reason why the K 1 treatment is superior to the K 2 treatment. It is possible that root absorption of K + and NO - 3 N are inter_related, and so an excessive K + concentration could affect the abso rption of NO - 3 N in the root. This would result in an effect on nitrogen absorption and transportation throughout the wheat plant, causing a reduction in wheat yield. The physiological mechanisms behind this effect require further study.
出处
《植物生态学报》
CAS
CSCD
北大核心
2003年第2期196-201,共6页
Chinese Journal of Plant Ecology
基金
国家自然科学基金资助项目( 39970 4 2 5)
科技部"无公害优质小麦生产关键技术集成与产业化示范"项目 ( 2 0 0BA516A12 )
关键词
小麦
旗叶
钾
蔗糖
籽料淀粉积累
酶活性
Potassium, Flag leaves, Starch accumulation of kernels, Enzyme activity
