Sweet corn is popular worldwide as vegetable. Though large numbers of sugary1 (su1)-based sweet corn germplasm are available, allelic diversity in su1 gene encoding SU1 isoamylase among diverse maize inbreds has not been analyzed. Here, we characterized the su1 gene in maize and compared with allied species. The entire su1 gene (11,720 bp) was sequenced among six mutant (su1) and five wild (Su1) maize inbreds. Fifteen InDels of 2–45 bp were selected to develop markers for studying allelic diversity in su1 gene among 19 mutant- (su1) and 29 wild-type (Su1) inbreds. PIC ranged from 0.15 (SU-InDel7) to 0.37 (SU-InDel13). Major allele frequency varied from 0.52 to 0.90, while gene diversity ranged from 0.16 to 0.49. Phylogenetic tree categorized 48 maize inbreds in two clusters each for wild- type (Su1) and mutant (su1) types. 44 haplotypes of su1 were observed, with three haplotypes (Hap6, Hap22 and Hap29) sharing more than one genotype. Further, comparisons were made with 23 orthologues of su1 from 16 grasses and Arabidopsis. Maize possessed 15–19 exons in su1, while it was 11–24 exons among orthologues. Introns among the orthologues were longer (77–2206 bp) than maize (859–1718 bp). SU1 protein of maize and orthologues had conserved α-amylase and CBM_48 domains. The study also provided physicochemical properties and secondary structure of SU1 protein in maize and its orthologues. Phylogenetic analysis showed closer relationship of maize SU1 protein with P. hallii, S. bicolor and E. tef than Triticum sp. and Oryza sp. The study showed that presence of high allelic diversity in su1 gene which can be utilized in the sweet corn breeding program. This is the first report of comprehensive characterization of su1 gene and its allelic forms in diverse maize and related orthologues.

甜玉米作为蔬菜在世界范围内广受欢迎。尽管有大量基于sugary1 ( su1 )的甜玉米种质可用，但尚未分析不同玉米自交系中编码SU1异淀粉酶的su1基因的等位基因多样性。在这里，我们表征了玉米中的su1基因并与近缘物种进行了比较。在六个突变体 ( su1 ) 和五个野生 ( Su1 ) 玉米自交系中对整个su1基因 (11,720 bp) 进行了测序。十五个InDel小号2-45基点的选择，开发标记为研究等位基因多样性SU1中19突变体- （基因SU1）和29个野生型（SU1) 近交。PIC 的范围从 0.15 (SU-InDel7) 到 0.37 (SU-InDel13)。主要等位基因频率从 0.52 到 0.90 不等，而基因多样性从 0.16 到 0.49 不等。系统发育树将 48 个玉米自交系分为两个簇，分别为野生型 ( Su1 ) 和突变型 ( su1 )。观察到su1 的44 种单倍型，其中三种单倍型（Hap6、Hap22 和 Hap29）共享一种以上的基因型。此外，还与来自 16 种草和拟南芥的su1 的23 个直向同源物进行了比较。玉米在su1 中拥有 15-19 个外显子，而在直向同源物中它是 11-24 个外显子。直向同源物中的内含子（77-2206 bp）比玉米（859-1718 bp）长。玉米和直向同源物的 SU1 蛋白具有保守的 α-淀粉酶和 CBM_48 结构域。该研究还提供了玉米及其直向同源物中 SU1 蛋白的理化特性和二级结构。系统发育分析表明玉米SU1蛋白与更紧密的关系P.霍氏真杆菌，S.双色和E. TEF比小麦属。和水稻sp。研究表明，su1基因存在高等位基因多样性，可用于甜玉米育种计划。这是su1综合表征的第一份报告 不同玉米和相关直向同源物中的基因及其等位基因形式。