SummaryMoso bamboo (Phyllostachys edulis) known as Mao Zhu (MZ) in Chinese exhibits various forms with distinct morphological characteristics. However, the evolutionary relationship among MZ forms and the mechanisms of culm shape variation are still lacking. Here, the main differences among MZ forms were identified as culm shape variation, which were confirmed by analysing MZ forms (799 bamboo culms) and MZ (458 bamboo culms) populations. To unravel the genetic basis underlying the morphological variations, 20 MZ forms were subjected to whole‐genome resequencing. Further analysis yielded 3 230 107 high‐quality SNPs and uncovered low genetic diversity and high genotype heterozygosity associated with MZ forms' formation. By integrating the SNP data of 427 MZ individuals representing 15 geographic regions, the origins of eight MZ forms were successfully traced using the phylogenetic tree and the identified common heterozygous loci. Meanwhile, transcriptomic analysis was performed using shoots from MZ and its two forms with culm shape variation. The results, combined with genomic analyses, demonstrated that hormone signalling related genes played crucial roles in culm variation. Co‐expression network analysis uncovered genes associated with multiple plant hormone signal transduction, especially auxin and cytokinin were involved in culm shape variation. Furthermore, the regulatory relationships of a specific transcription factor and their target genes associated with auxin and ethylene signalling were validated by yeast one‐hybrid, electrophoretic mobility shift assays, and dual‐luciferase reporter. Overall, this study provides important insights into the culm shape variation formation in bamboo, which facilitates to breed new varieties with novel culms.

中文翻译：

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毛竹形态的进化关系和涉及竹秆形状变异的多激素调节级联

摘要毛竹（毛竹）中文称为毛竹（MZ），其形态多样，形态特征鲜明。然而，MZ形态之间的进化关系和秆形态变异的机制仍然缺乏。在这里，MZ 形式之间的主要差异被确定为竹秆形状变异，这通过分析 MZ 形式（799 竹秆）和 MZ（458 竹秆）群体得到证实。为了揭示形态变异背后的遗传基础，对 20 个 MZ 形式进行了全基因组重测序。进一步分析产生了 3 230 107 个高质量的 SNP，并发现与 MZ 形式形成相关的低遗传多样性和高基因型杂合性。通过整合代表 15 个地理区域的 427 个 MZ 个体的 SNP 数据，利用系统发育树和已识别的常见杂合位点成功追踪了 8 个 MZ 形式的起源。同时，使用 MZ 及其两种具有秆形状变异的芽进行转录组分析。结果与基因组分析相结合，证明激素信号相关基因在秆变异中发挥着至关重要的作用。共表达网络分析发现与多种植物激素信号转导相关的基因，特别是生长素和细胞分裂素与秆形状变异有关。此外，通过酵母单杂交、电泳迁移率变动分析和双荧光素酶报告基因验证了特定转录因子及其与生长素和乙烯信号传导相关的靶基因的调节关系。总的来说，这项研究为竹子茎形状变异的形成提供了重要的见解，这有助于培育具有新茎的新品种。