铁肥浸种对玉米发育前期生长及光合荧光特性的影响

Effects of Seed Soaking with Iron Fertilizer on Growth and Photosynthetic Characteristics of Maize(Zea mays L.)in Early Stage

以‘郑单958’为材料,研究铁肥(FeSO_4·7H_2O)浸种对玉米发育前期生长和光合荧光特性的影响。设置3个铁肥质量分数水平(0.05%、0.075%、0.125%),以清水为对照(CK)。结果表明:随着浸种质量分数的增加,玉米干物质积累、叶面积、株高和茎粗先升高后降低,0.075%处理的干物质积累和叶面积显著高于CK;铁肥浸种提高了叶绿素相对含量(SPAD值),其中0.075%处理显著高于CK,0.075%处理的玉米叶片净光合速率(P_n)在七叶期、拔节期较CK分别提高24.1%和20.7%,0.075%处理的PSⅡ最大光化学效率(F_v/F_m)、实际光化学效率(Yield)和相对电子传递速率(ETR)均高于CK,非光化学猝灭(q_N)相反。综合分析各生长指标与光合荧光参数,0.075%的FeSO_4·7H_2O为关中平原夏玉米铁肥浸种处理的适宜质量分数。

In this experiment,‘Zhengdan 958’ was used to investigate the effects of seed soaking with iron fertilizer on growth,fluorescence efficiency and photosynthetic characteristics of maize during early stage.The treatments were three levels of FeSO4 · 7H2O mass fraction （0.05%,0.075%,0.125 %）,and water application served as control （CK）.Plant height,stem diameter,dry matter accumulation and leaf area were measured at trifoliate stage,photosynthetic characteristics and chlorophyll fluorescence parameters measured at septfoliate stage and jointing stage,respectively.The results showed that,dry matter accumulation rate,leaf area,plant height and stem diameter increased first and then decreased with the increase of iron fertilizer mass fraction.Dry matter accumulation and leaf area were significantly higher at 0.075% mass fraction as compared to CK;seed soaking with iron fertilizer increased the relative chlorophyll content （SPAD value）,of which 0.075% significantly performed better than CK,net photosynthetic rate of 0.075 % were 24.1% and 20.7% higher than that of CK at septfoliate stage and jointing stage.Maximum photochemical efficiency of PS Ⅱ after dark adaptation （Fv/Fm）,actual photochemical efficiency of PS Ⅱ in the light （Yield）,and relative electron transport rate （ETR） of 0.075 % were higher than that of CK,where as non-photochemical quenching （qN） was opposite.By comprehensive analysis of maize growth indexes and photosynthetic parameters,0.075% of iron fertilization with seed soaking is recommended as a proper mass fraction for enhancing maize quality in Shaanxi Guanzhong plain.