Knowledge of the genetic diversity and relationships among maize inbred lines can facilitate germplasm management and plant breeding programmes. The study investigated the level of genetic diversity among S6 lines developed from a tropical-adapted shrunken-2 (sh-2) maize population and their relationship with normal endosperm tropical inbred lines of known heterotic groups. Ninety-one sh-2 maize inbred lines (UI1-UI91) developed in the University of Ibadan super-sweet Maize Breeding Programme were genotyped at 30 simple sequence repeat (SSR) loci, alongside five normal endosperm maize inbred lines viz. TZi3, TZi4, TZi10, TZi12 and TZi15, four of which belong to two heterotic groups. Twenty-three SSR markers were polymorphic and detected a total of 61 alleles, with a range of 2–7 and an average of 2.65 alleles per locus. The polymorphic information content ranged from 0.12 in bnlg1937 to 0.77 in phi126, with an average of 0.36. The gene diversity (He) averaged 0.43. Cluster analysis resulted in five groups consisting of 16, 36, 17, 23 and 3 inbred lines, with one sh-2 line ungrouped. TZi 12 and TZi 15, both of which are of the same heterotic group, clustered with TZi 3 of another heterotic group. Considerable genetic diversity exists among the 96 inbred lines. Only two of the five normal endosperm lines shared clusters with the sh-2 lines. The clustering of the normal endosperm inbred lines is not related to their established heterotic patterns. Inbred lines in two clusters offer the possibility of guiding the exploitation of heterosis among the sh-2 lines.

中文翻译：

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基于微卫星标记的热带shrunken-2玉米自交系遗传多样性及其与已知杂种优势分类的正常胚乳自交系的关系

了解玉米自交系之间的遗传多样性和关系可以促进种质管理和植物育种计划。该研究调查了人类的遗传多样性水平小号6从适应热带发展而来的线条缩小-2(sh-2) 玉米种群及其与已知杂种优势群的正常胚乳热带自交系的关系。九十一sh-2在伊巴丹大学的超甜玉米育种计划中开发的玉米自交系 (UI1-UI91) 在 30 个简单序列重复 (SSR) 位点以及 5 个正常胚乳玉米自交系即基因型上进行了基因分型。TZi3、TZi4、TZi10、TZi12 和 TZi15，其中四个属于两个杂种优势群。23 个 SSR 标记具有多态性，共检测到 61 个等位基因，范围为 2-7，每个基因座平均有 2.65 个等位基因。多态信息含量从 bnlg1937 的 0.12 到 phi126 的 0.77 不等，平均为 0.36。基因多样性 (He) 平均为 0.43。聚类分析得出五个组，包括 16、36、17、23 和 3 个自交系，其中 1 个sh-2线未分组。同属杂种优势群的TZi 12和TZi 15与另一个杂种优势群的TZi 3 聚在一起。96 个自交系之间存在相当大的遗传多样性。五个正常胚乳系中只有两个与sh-2线。正常胚乳自交系的聚类与其建立的杂种优势模式无关。两个集群中的自交系提供了指导利用杂种优势的可能性sh-2线。