Breeding efforts in West and Central Africa (WCA) have focused on the development of Low‐N‐tolerant (LNT) maize inbreds and their classification into heterotic groups. This study was conducted to classify LNT maize lines into heterotic groups using testcross performance, morphological and SNP markers and to compare the consistency of groupings by the three methods. Thirty‐six LNT inbreds were crossed to two contrasting inbred testers to generate 72 testcrosses that were evaluated under low‐N conditions in Nigeria in 2014. Also, the 36 inbreds and the two testers were evaluated for per se performance under similar conditions as the testcrosses in 2014 and genotyped in 2015 using 1,123,196 SNP markers. Based on testcross performance, 33 of the 36 LNT inbreds were grouped by the two testers. Morphological characterization from per se performance and genetic relationship by SNP markers classified the inbreds into four groups that were inconsistent with their pedigree. Correlation analysis showed non‐concurrence of the three grouping methods. However, information from these groupings would assist in reducing the number of crosses to be made and evaluated.

中文翻译：

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利用测试杂交性能，形态性状和SNP标记评估热带低氮耐性玉米（Zea mays L.）自交系的杂种模式

西非和中非（WCA）的育种工作集中在耐低氮（LNT）玉米自交系的发育及其分类上。进行这项研究的目的是使用testcross性能，形态学和SNP标记将LNT玉米品系划分为杂种组，并比较这三种方法的分组一致性。将36个LNT自交系与两个对比自交测试仪进行杂交，以生成72个测试杂交，并在2014年尼日利亚的低氮条件下进行了评估。此外，还对36个自交系和两个测试仪在与测试交集相似的条件下进行了性能评估在2014年进行基因分型，并在2015年使用1,123,196个SNP标记进行基因分型。根据测试交叉性能，由两个测试人员对36个LNT自交系中的33个进行了分组。根据本身的表现和SNP标记的遗传关系对形态进行表征，将近交者分为与其血统不一致的四类。相关分析表明，这三种分组方法不一致。但是，来自这些分组的信息将有助于减少要进行和评估的杂交次数。