施锌对盐碱地玉米生理特性及籽粒锌含量的影响

为研究不同施锌水平对盐碱地玉米生理特性及籽粒锌含量的影响，以科河699为供试材料，采用随机区组设计进行田间试验，根据不同施锌肥方式设置6个处理：T0（0 kg·hm^-2）、T1（7.5 kg·hm^-2）、T2（15 kg·hm^-2）、T3（22.5 kg·hm^-2）、T4（30 kg·hm^-2）、T5（37.5 kg·hm^-2），测定不同处理下玉米生理特性、籽粒锌含量及产量。结果表明，施锌降低了盐碱地玉米叶片相对电导率、脯氨酸含量、丙二醛含量，灌浆期T3处理的叶片相对电导率、脯氨酸含量、丙二醛含量分别较T0处理降低了22.3%、24.7%、15.9%；施锌提高了玉米叶片保护性酶活性，大喇叭口期T3处理的超化物歧化酶（superoxide dismutase，SOD）、过氧化物酶（peroxidase，POD）和过氧化氢酶（catalase，CAT）活性分别较T0处理提高了68.7%、152.1%和72.6%；同时，玉米籽粒锌含量和产量随施锌量的增加呈先增加后降低的趋势，均在T3处理下达到最大值；T3处理能提高玉米叶片及茎秆中锌素的转移率及贡献率，减少玉米秃尖，增加穗长、穗粒数和百粒重，从而提高玉米籽粒锌含量和产量。以上结果表明，适量施锌肥可以提高玉米叶片生理活性，增强玉米对盐碱环境的抵抗能力，且当施锌量为22.5 kg·hm^-2时玉米产量及籽粒锌含量均最高。

Effects of Zinc Fertilizer Application on Physiological Characteristics and Grain Zn Content of Maize in Saline-alkali Soil

In order to study the effects of different zinc application rates on the physiological characteristics and grain zinc content of maize in saline-alkali land， a field experiment was conducted with Kehe 699 as the test material by random block design. 6 treatments were set up： T0（0 kg·hm^-2）， T1（7.5 kg·hm^-2）， T2（15 kg·hm^-2）， T3（22.5 kg·hm^-2）， T4（30 kg·hm^-2）， T5（37.5 kg·hm^-2）， and the physiological characteristics， grain zinc content and yield of maize under different treatments were measured. The results showed that zinc application decreased the relative conductivity， proline and MDA content of maize leaves in saline-alkali soil. Compared with T0 treatment， the relative conductivity， proline content and malondialdehyde content under T3 treatment were decreased by 22.3%， 24.7% and 15.9%， respectively in the filling stage. Zinc application increased the protective enzyme activity of maize leaves， and the superoxide dismutase（SOD）， peroxidase（POD） and catalase（CAT） activities in T3 treatment at big trumpet stage were increased by 68.7%， 152.1 % and 72.6% respectively， compared with in T0 treatment. At the same time， the zinc content in maize grain first increased and then decreased with the increase of zinc application rate， and reached the maximum value under T3 treatment. T3 treatment could improve the transfer rate and contribution rate of zinc in leaves and stems， reduce the bare tip of maize， increase ear length， grain number and 100-grain weight， thus increasing the zinc content and yield of maize grains. The results of this study showed that appropriate application of zinc fertilizer could improve the physiological activity of maize leaves and enhance the resistance of maize in saline-alkali environment， and the maize yield and grain zinc content were the highest when the zinc application rate was 22.5 kg·hm^-2.