不同种植密度下兰考矮早八茎蘖叶片内源激素差异及其与分蘖成穗的关系

Difference of Endogenous Hormones in Leaves between Main Stem and Tillers and Its Effect on Spike Formation in Large Spike Winter Wheat Cultivar Lankao Aizao 8 under Different Plant Densities

在不同种植密度下,于拔节期前后测定兰考矮早八主茎和一级分蘖的第一分蘖(分蘖I)和第二分蘖(分蘖II)各时期上部第一片完全展开叶内吲哚乙酸(IAA)、玉米素核苷(ZR)和脱落酸(ABA)含量。结果表明,叶片内IAA和ZR含量表现为主茎>分蘖I>分蘖II,其分蘖与主茎的差距在拔节前期开始加大;叶片内ABA含量表现为分蘖>主茎,其差距开始加大的时期比其他激素晚6～12d。各激素含量在主茎与分蘖间的差距随密度的增大而增加,且差距达到一定程度时导致分蘖衰亡。激素间平衡与分蘖成穗关系更为密切,分蘖叶片中IAA/ABA和ZR/ABA比值低不利于分蘖最终成穗。激素含量比值在分蘖和主茎叶片中出现差距的时间要早于单一激素含量在分蘖与主茎中出现差距。与单个激素含量相比,激素之间的平衡以及分蘖与主茎激素平衡的差距可能与分蘖成穗的关系更为密切。分蘖中IAA/ABA和ZR/ABA比值占主茎中相应比值的比例可使判断成穗蘖和衰亡蘖出现差距的时间提前至二棱末期,比单一激素含量判断提前6～22d。

Contents of indoleacetic acid （IAA）, zeatin riboside （ZR）, and abscisic acid （ABA） were determined in the first fully expanded leaves of the first and the second tillers, and the main stem of Lankao Aizao 8 under different planting densities. The contents of IAA and ZR were higher in the main stem than in tillers, and the content of ABA was higher in tillers than in the main stem. The time of initiated increasing for content differences between the main stem and tillers was since early jointing stage for IAA and ZR and 6 to 12 d later for ABA. These differences on hormone contents enhanced with the growing of planting density, leading to senescence of tillers ultimately. Compared with single hormone content, the balance of endogeneous hormones was more important for the formation of spike in tillers. The leaf ZR/ABA value and tiller/stem ratio for IAA/ABA and ZR/ABA made the judgment for the critical period of tiller senescence and development advanced to double-ridge telophase, and 6 to 22 d earlier than that based on single hormone content.