高产夏玉米镁的吸收与再分配研究

本文就高产条件下两种株型夏玉米在不同生育时期对镁的吸收、积累及镁在不同器官间的分配与再分配进行了分析。结果表明，玉米植株相对含镁量在一生中基本呈现前期高、后期低的变化趋势。植株吸收的镁在吐丝前主要分配到叶片、茎秆和叶鞘中，吐丝后镁的分配重点则转向籽粒。玉米对镁的吸收有２个高峰期，平展型品种分别在拔节至大喇叭口期和籽粒形成期；紧凑型品种分别在大喇叭口至吐丝期和灌浆始期。每形成百公斤籽粒吸收镁０．３８２～０．３９７ｋｇ。籽粒中的镁有３７．０６％～４４．０５％来自于其它器官镁的再分配。平展型品种向籽粒转移镁最多的器官是叶鞘和叶片，紧凑型品种向籽粒转移镁最多的器官是叶鞘、雄穗和叶片。

Accumulation and Distribution of Magnesium in Corn

In order to learn the absorption, accumulation and distributions of magnesium by and in different organs of corn during plant development,the study was conducted in high yield conditions with two corn hybrids of different plant-types,i. e. erect-leaf hybrid and wide-leaf hybrid. The result showed that percentage content of magnesium in corn plant decreased as the plant developing. Magnesium absorbed by the plant accumlated chiefly in leaves, stems and leaf-sheathes before silking and after then, the developing kernel became the most important sink for magnesium. Two peaks of magnesium accumulation were found in both hybrids. The first peak was from 8-leaf stage to 12-leaf stage for the wide-leaf hybrid, and from 12-leaf stage to silking stage for the erect-leaf hybrid. The second one appeared from silking to 15d after silking and from 15d, after silking to 30d respectively. It absorbs 382-397 grams of magnesium to yield one hundred kilograms of seeds. Of the total amount of kernel magnesium, about 37%～45% was translocated form other parts of the plant during grain filling period.