叶面喷施硅制剂对滨海盐碱地夏玉米叶片光合性能及籽粒产量的影响

Effects of foliar silicon sprays on leaf photosynthetic performance and grain yield of summer maize in coastal saline-alkali soil

硅是作物生长的有益元素,有助于缓解作物遭受的盐胁迫。本试验以大田试验种植的登海605为试验材料,分别于小喇叭口期(V9)、大喇叭口期(V12)和抽雄期(VT)进行喷施硅制剂(8 g L^(–1) Si O_(2))处理,并以同期喷施等量清水为对照,旨在探讨不同时期叶面喷施硅制剂对滨海盐碱地夏玉米叶片光合性能及籽粒产量的影响,为滨海盐碱地夏玉米抗逆增产提供理论依据。结果表明,与对照相比,不同时期喷施叶面硅制剂,均能够显著增加盐碱地夏玉米叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性,降低丙二醛(MDA)含量,缓解光合器官的损伤和光合色素的降解;V9、V12、VT期叶面喷施硅制剂处理R6期,叶面积指数2年平均分别提高6.28%、7.16%、6.66%,2023年R3期叶绿素含量分别提高6.62%、7.52%、7.47%。喷施硅制剂提高了叶片净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(G_(s))以及胞间CO_(2)浓度(C_(i));V9、V12、VT期叶面喷施硅制剂处理R3期P_n两年平均分别提高11.64%、11.73%、16.39%。光合速率提升促进了干物质积累及其向籽粒的转运,R6期干物质积累量分别提高8.46%、8.88%、9.67%,穗粒数和千粒重显著提高,最终籽粒产量在2022年和2023年分别提升了7.24%、10.47%、12.94%和6.23%、7.99%、11.25%;综上,本试验条件下,滨海轻中度盐碱地夏玉米生产过程中以VT期喷施叶面硅制剂的增产效果最佳,主要是缓解了氧化胁迫、提升了光合性能、促进了干物质积累与转运。

Silicon is a beneficial element for crop growth and can effectively alleviate salt stress in crops.This study aims to ex-plore the alleviating effect of foliar spraying of silicon on salt stress in coastal saline-alkali summer maize in China,providing a theoretical basis for enhancing stress resistance and increasing yield in coastal saline-alkali summer maize.Denghai 605,planted in the field test,was selected as the test material.A silicon preparation(8 g L^(-1) SiO_(2))was sprayed at the V9,V12,and VT stages,while the control group was sprayed with the same amount of water.The effects of foliar spraying with silicon preparation at different stages on leaf photosynthetic performance and grain yield of summer maize in coastal saline-alkali soil were investigated.The results demonstrated that foliar spraying of silicon preparations at different stages significantly increased the activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)in saline-alkali summer maize leaves compared to the control group.It also reduced the content of malondialdehyde(MDA),alleviating the damage to photosynthetic organs and the degrada-tion of photosynthetic pigments.The leaf area index at the R6 stage increased by 6.28%,7.16%,and 6.66%in the V9,V12,and VT stages,respectively,while the chlorophyll content at the R3 stage increased by 6.62%,7.52%,and 7.47%in 2023.Silicon spraying increased the net photosynthetic rate(Pn),transpiration rate(T_(r)),stomatal conductance(G_(s)),and intercellular CO_(2) con-centration(Ci)of leaves.Foliar spraying of silicon preparation at the V9,V12,and VT stages increased the Pn of the R3 stage by 11.64%,11.73%,and 16.39%,respectively.The biomass at the R6 stage increased by 8.46%,8.88%,and 9.67%,respectively,and there was a significant increase in the number of grains per spike and 1000-grain weight.Ultimately,the grain yield increased by 7.24%,10.47%,12.94%,6.23%,7.99%,and 11.25%in 2022 and 2023,respectively.In summary,under the conditions of this experiment,foliar spraying of silicon preparations at the VT stage had the most significant effect on increasing yield in summer maize production in coastal light to moderate saline-alkali soil.This effect was mainly attributed to the alleviation of oxidative stress,improvement of photosynthetic performance,and promotion of biomass accumulation and transportation.