钾素对玉米子粒淀粉形成及产量的影响

2018-2019年在宁夏银川平吉堡开展田间试验，设6个(0、60、120、180、240和300 kg/hm²)钾肥用量，研究钾素用量对玉米子粒中淀粉合成酶活性、淀粉含量及产量的调控机理。结果表明，施钾显著提高玉米子粒淀粉含量及淀粉合成酶活性，降低直链淀粉与支链淀粉的比值，各处理中以施钾量为180 kg/hm²时子粒淀粉含量、酶活性和产量最高。子粒中淀粉酶活性于开花后35 d达最大值，180 kg/hm²钾肥处理比不施钾肥，腺苷二磷酸葡萄糖焦磷酸化酶(AGP)、尿苷二磷酸葡萄糖焦磷酸化酶(UGP)、淀粉分支酶(SBE)、可溶性淀粉合成酶(SSS)和束缚态淀粉合成酶(GBSS)活性分别提高38.97%、22.63%、27.64%、36.19%和28.23%。成熟期180 kg/hm²处理比不施钾肥处理，总淀粉含量提高29.82%，直链淀粉与支链淀粉的比值降低11.36%，产量增加18.14%。综合考虑玉米淀粉合成酶活性、淀粉含量及淀粉组分和产量等因素，宁夏旱区滴灌条件下的适宜施钾量为180 kg/h...

Effect of Potassium on Starch Formation and Yield of Maize Kernel

To illustrate the control mechanism of potassium application rate to starch synthase activity, starch content and yield in maize kernel, which provided a theoretical basis for increasing yield, high efficiency and saving fertilizer technology of maize in the arid region of Ningxia. A field experiment was conducted in Pingjipu, Yinchuan, Ningxia from 2018 to 2019. Six potassium application rates were set, which were 0, 60, 120, 180, 240 and 300 kg/ha in turn. Potassium application significantly increased the maize kernel starch content and starch synthase activity, and decreased the ratio of amylose to amylopectin. Among all treatments, the kernel starch content, enzyme activity and yield were the highest when potassium application was 180 kg/ha. The amylase activity in kernel reached the maximum at 35 days after flowering. Compared with 0 kg/ha treatment, the activities of AGP, UGP, SBE, SSS and GBSS in 180 kg/ha treatment increased by 38.97%, 22.63%, 27.64%, 36.19% and 28.23% respectively. Compared with 0 kg/ha treatment, the total starch content of 180 kg/ha treatment in mature stage increased by 29.82%, the ratio of amylose to amylopectin decreased by 11.36%, and the yield increased by 18.14%. Considering the factors including starch synthase activity, starch content, starch composition and yield of maize, the suitable potassium application rate under drip irrigation in Ningxia is 180 kg/ha.