光周期对青饲玉米耐高氮的调控效应

Regulatory Effects of Photoperiod on High Nitrogen Tolerance in Ensilage Corn

以光周期敏感型‘华农1号’青饲玉米为材料,在大田条件下,设置N1(75kg/hm2)、N2(225kg/hm2)、N3(375kg/hm2)3个氮素水平和3个光周期处理(16h、13h和10h),分析了其在不同光照长度条件下耐高氮胁迫的能力,探讨光周期对玉米氮高效相关的农艺性状和光合特性指标的影响。结果表明,(1)16h光照处理下,玉米植株的根长、根表面积、根体积分别比10h处理增加了113.19%、45.73%和97.71%,叶片叶绿素含量与净光合速率比10h处理分别提高97.90%和60.24%,且根长、根体积、叶绿素含量和净光合速率在16h和10h处理下差异极显著;16h处理与10h处理叶片数的平均相差值(12)显著,根系直径随光周期延长逐渐减小,但光周期对植株分蘖数无显著影响。(2)‘华农1号’青饲玉米地下部和地上部部分农艺性状指标,在16h长光照处理下随氮素水平的提高而增加,表现出耐高氮胁迫的生物学特征;在10h短光照处理下氮素水平过高相关性状指标反而下降。(3)随着光照时间逐渐延长,地上部生物量逐渐显著增加。研究发现,光周期敏感型‘华农1号’青饲玉米具有较强的耐高氮能力,长光周期促进了其植株营养生长阶段的生长发育,增强了其对高氮的适应能力。

Under the conditions of 16hlight/8hdark,13hlight/11 hdark and 10hlight/14 hdark,the authors studied the effects of photoperiod on agronomic traits and photosynthetic characteristics of ensilage corn‘Huanong 1’,at different nitrogen levels of N1（75kg/hm2）,N2（225kg/hm2）,N3（375kg/hm2）.The capacity of tolerating high nitrogen stress was analyzed.The results showed that：（1）the root length,root surface area and root volume were increased by 113.19%,45.73% and 97.71%,respectively,under 16 h light,compared with 10 hlight.The contents of chlorophyll and net photosynthesis rate of leaves were higher by 97.90% and 60.24% under 16 hlight.The leaf number under 16 hlight was twelve more than that under 10 hlight,with extremely significant difference.While photoperiod did not influence plant tiller number significantly.（2）Root diameter was decreased gradually with the extension of photoperiod.‘Huanong 1’ensilage corn displayed the biological characteristics of resisting high nitrogen stress under 16 h light,and the indexes of root morphology and some agronomic traits were improved with increasing of nitrogen level,but the traits indexes declined gradually with the increasing of nitrogen level under 10 hlight.（3）As the photoperiod extended gradually,aboveground biomass also increased significantly.Therefore,the authors believed that long photoperiod promoted the growth and development of photoperiod sensitive corn‘Huanong 1’,and also enhanced the adaptation ability of it to high nitrogen.