夏玉米不同栽培模式花后叶片光合性能的差异

光合作用是作物生长发育及产量形成的重要生理过程,不同栽培模式会显著影响夏玉米花后叶片光合性能。本研究于2018—2019年设置大田试验,以登海605为试验材料,当地农户栽培管理模式(farmer management mode,FP)为对照,通过综合优化种植密度、肥料运筹和种植方式等措施设置超高产栽培模式(super high yield mode,SH)、高产高效栽培模式(high-yield and efficient mode, HH)。分析不同栽培模式叶面积指数、叶绿素含量、气体交换参数和快速叶绿素荧光诱导动力学曲线(OJIP)等的变化特点,探究栽培模式对夏玉米花后叶片光合性能的调控效应。结果表明,不同栽培模式可显著影响夏玉米成熟期群体生物量,SH、HH模式较FP两年分别平均提高27.77%和7.43%,且HH模式花后群体生物量显著增加。不同栽培模式夏玉米花后叶片光合速率均呈现下降趋势,吐丝后30d(R₁+30d)时下降幅度较大。与FP相比, SH、HH在R₁和R₁+30 d净光合速率(net photosynt...

Differences in photosynthetic performance of leaves at post-flowering stage in different cultivation modes of summer maize(Zea mays L.)

Photosynthesis plays an important role in crop growth and yield formation.Different cultivation patterns can significantly affect the photosynthetic performance of leaves at post-flowering stage in summer maize.In order to explore the effects of different cultivation modes on the photosynthetic performance of summer maize leaves at post-flowering stage,field experiments were carried out with Denghai 605 maize hybrid variety as experimental material from 2018 to 2019 in Tai’an,Shandong,China.With the local farmer management mode(FP)as the control,the super-high-yield cultivation mode(SH)and high-yield and high-efficiency cultivation mode(HH)by comprehensively optimizing the planting density,fertilizer planting and management mode were set in this study.Leaf area index,chlorophyll content,gas exchange parameters,rapid chlorophyll fluorescence induction kinetic curve(OJIP)were evaluated,which indicated significant differences in biomass of different cultivation modes at maturity stage.Compared with FP,the biomass of SH and HH increased by 27.77%and 7.43%,respectively,and the population biomass at post-flowering stage of HH increased significantly as well.Besides,the photosynthetic rate all declined in different cultivation modes,reaching the highest degree of decline on the 30th day at post-flowering stage(R₁+30 d).In contrast with FP,the net photosynthetic rate(Pn)of SH and HH increased at post-flowering stage stage(R₁)by 21.63%and 12.96%,respectively,and on the 30th day(R₁+30 d)at post-flowering stage by 35.37%and 12.37%,respectively,which could maintain a higher level of photosynthetic capacity.In addition,these results revealed that the differences of net photosynthetic rate among the different cultivation modes were caused by non-stomatal factors.The stomatal conductance(G_s)of SH and HH was increased at the silking stage by 18.36%,16.66%,26.16%,and 10.74%,respectively,and while on the 30th day at post-flowering stage intercellular carbon dioxide(C_i)declined by 12.85%,7.34%,14.08%,and 9.75%,respectively.Compared with FP,W_kand V_jof SH and HH significantly decreased,indicating that SH and HH apparently improved the performances of both electron donor and acceptor sides of electron transport chain in PSII reaction center,the quantum yield of electron transfer(φ_E0),the electron transfer ability as well as the reaction center activities of PSII and the coordination between PSI and PSII.In conclusion,SH and HH effectively improved the photosystems performance,increased the net photosynthetic rate,and prolonged duration of high photosynthesis rate,resulting in the increase of the population biomass and high yield.