不同供氮水平对玉米光合特性的影响

EFFECTS OF NITROGEN SUPPLY ON PHOTOSYNTHETIC TRAITS OF MAIZE

不同供氮水平对玉米幼苗叶片的叶绿素含量、光合速率及叶绿素荧光特性等有着显著影响。随着供氮水平的降低,叶绿素含量、净光合速率(Pn)、光饱和点、光补偿点、PSⅡ最大光化学量子产量(Fv/Fm)、PSⅡ实际光化学量子产量(ΦPSⅡ)、光化学淬灭系数(qP)逐渐降低,非光化学淬灭(NPQ)逐渐增加。而与适中氮比较,在较低氮下各品种的降低或增加幅度不同,其中雅玉2号的叶绿素含量、Pn、ΦPSⅡ、Fv/Fm、qN的降低幅度和NPQ的增加幅度均较小,成单14号的各项指标的变幅都最大,西单2号、农大108和登海1号居中。

Nitrogen significantly affects chlorophyll content, photosynthetic rate and chlorophyll fluorescence of the leaves of maize seedlings. With a decline in the rate of N supply, chlorophyll content, net photosynthetic rate (Pn), light saturation point, light compensation point maximal photochemical quantum yield of PS II (Fv/Fm), actual quantum yield of PS II (ФPS II) and photochemical quenching co-efficient (qP) decreased and non-photochemical quenching (NPQ) increased. As compared with adequate N supply, lower N rate induced a decrease in chlorophyll content, Pn, ФPS II, Fv/Fm and qP and an increase in NPQ to different extents in different maize varieties. The fluctuation was the smallest in Yayu 2, followed by Xidan 2, Nongda 108 and Denghai 1 and was the greatest in Changdan 14.