Optimizing root systems is one crucial point in drought tolerance breeding of plants. Introducing root‐related traits to breeding programmes is time‐consuming and laborious. Most of the commonly used methods are not suitable to be applied in a larger amount of plants. Here we present a study applying a DNA‐based root phenotyping method (root DNA density; RDD) for phenotyping the root system of maize. Twenty‐one maize inbred lines were investigated in a rain‐out shelter experiment and 19 maize inbred lines in a greenhouse experiment under well‐watered and drought conditions. Beside other commonly used root traits, agronomic traits of the plants were recorded and compared to RDD. Within root traits, RDD showed high significant genotypic variation and the highest repeatabilities of up to 72.4%. In contrast to most agronomic traits, repeatabilities increased under drought conditions. Values showed also good correlations between rain‐out shelter and greenhouse trial, indicating the potential of this method for obtaining comparable results across different environments.

中文翻译：

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在不同供水条件下评估玉米（Zea mays）根DNA密度的遗传变异

优化根系是植物抗旱育种的关键点之一。将根系相关性状引入育种程序既费时又费力。大多数常用方法都不适合在大量植物中使用。在这里，我们提出了一项基于DNA的根表型方法（根DNA密度； RDD）用于玉米根系统表型的研究。在雨水充足的干旱条件下，对二十一个玉米自交系进行了防雨棚试验，在温室实验中对19个玉米自交系进行了研究。除其他常用的根系性状外，还记录了植物的农艺性状并与RDD进行了比较。在根性状内，RDD显示出很高的基因型变异和最高的重复性，最高可达72.4％。与大多数农艺性状相反，在干旱条件下，重复性增加。值还表明，防雨棚和温室试验之间也具有良好的相关性，表明该方法在不同环境中获得可比结果的潜力。