玉米不同自交系吐丝后锌吸收与分配特征

Characteristics of zinc absorption and distribution after silking in the different maize inbred lines

以籽粒中锌浓度较高的自交系‘CO109’、‘旅28’(简称高锌自交系)和较低的自交系‘陈322’、‘琼51’(简称低锌自交系)为供试材料,设置吐丝期去除穗上部叶、去除穗下部叶和保留所有叶片3个取样处理,比较不同基因型玉米在吐丝后锌吸收与分配上的差异,解析高锌与低锌自交系籽粒中锌的主要来源。结果表明:不同自交系吐丝期和成熟期同一部位叶片中锌浓度和积累量存在显著差异。吐丝期的同一叶位籽粒高锌自交系‘旅28’、‘CO109’的叶片锌浓度显著高于籽粒低锌‘陈322’、‘琼51’;不同玉米自交系各部位叶片成熟期锌积累量比吐丝期均表现出不同幅度的增加,籽粒低锌的两个自交系增加幅度要大于籽粒高锌的两个自交系。吐丝后锌在籽粒和叶片的分配存在显著基因型差异,籽粒高锌自交系‘CO109’和‘旅28’向籽粒分配锌的比例均超过75%,显著高于籽粒低锌自交系;而低锌自交系‘陈322’只有42.7%的锌分配给籽粒,大部分累积在叶片中。与保留所有叶片植株相比,去除功能叶并没有影响原籽粒锌浓度,籽粒高锌自交系仍显著高于籽粒低锌自交系;而去除功能叶对籽粒的积累量有显著影响,降低了成熟期籽粒锌的积累量,其降低的幅度因基因型不同而异,籽粒锌浓度高并不一定籽粒的锌累积量也高。

To distinguish the zinc uptake and distribution in inbred lines of maize with different genotypes and to analyze the characteristics of zinc source in both high zinc and low zinc inbred lines,the experiment was performed using high grain zinc concentration inbred lines of‘CO109’,‘lv28’and low grain zinc concentrations inbred lines of‘chen322’,‘qiong51’.Three treatments were set up for the inbred lines during the silking stage as follows:1.Remove the upper leaves of the panicle.2.Remove the lower leaves of the panicle.3.Reserve all leaves.The differences of zinc concentration and accumulation were analyzed statistically.There are significant genotypic difference of zinc concentration and accumulation at the same leaf position during silking and mature stages.At the same leaf position,the zinc concentration of line‘CO109’and‘lv28’were much higher than that of line‘chen322’and‘qiong51’at silking stage.The accumulation of zinc in the mature stage of inbred lines show a different amplitude increase compared with the silking stage.The two inbred lines with low zinc were increased higher than the two inbred lines with high zinc concentration.From silking to maturity,zinc distribution in grain and leaves was remarkable difference among genotypic lines,and the ratio of zinc distributed to grain was more than 75%in the inbred lines‘CO109’and‘lv28’,which was significantly higher than that of low zinc inbred lines,which the ratio of zinc distributed to grain was 42.7%in the inbred line‘chen322’.Compared with the intact plants,removal of functional leaves did not affect the zinc concentration of grain,and the zinc concentration of the high zinc concentration inbred lines were still significantly higher than that of the low zinc inbred lines.However,removal of functional leaves reduced the accumulation of zinc at the mature stage.The decrease range was different among genotypes,and high grain zinc concentration did not mean that the accumulation of grain zinc was necessarily high.Thus,this study provides useful information for the selective breeding of zinc-rich maize.