Abstract: Leaves are the main organs for material communication and energy conversion between plant bodies and the surrounding environment,and play a key role in plant growth and development. In this study,the phenotypic identification of pigeonpea smaller-leaves mutants (SLM) obtained by aero mutagenesis showed that their leaf width,leaf length and leaf area were significantly smaller than those of wild type (P<0.01),while the leaf length-to-width ratio was significantly larger (P<0.01). Through phenotypic observation of the F₂ population constructed by hybridization of SLM and wild type ‘ICPL81-3’,it was found that the leaf width,leaf length,length to width ratio and leaf area of different single plants varied greatly and were significantly correlated in the F₂ population,among which leaf width and leaf area showed obvious bimodal distribution,and the leaf width phenotype conformed to 3∶1 separation (X²2_0.05,1=3.84),indicating that the smaller leaves trait is controlled by a recessive single gene. SSR marker and InDel marker combined with bulk segregation analysis (BSA) were used for smaller leaves initial gene mapping,and one InDel marker PA094 with obvious differences in the two gene pools was screened,and the detection of each single plants of the gene pools and the F₂ population confirmed that PA094 and the smaller-leaves trait had a stable linkage relationship. The results provide a basis for the subsequent fine mapping of and cloning of the smaller-leaves gene.

Key words: Pigeonpea, Smaller leaves mutant, Phenotypic identification, Genetic analysis, Gene mapping

摘要： 叶片是植物体与周围环境之间进行物质交流与能量转化的主要器官，对植株的生长发育起着关键的作用。本研究对前期航空诱变获得的木豆（Cajanus cajan）小叶突变体进行了表型鉴定。结果表明：其叶宽、叶长、叶面积与野生型相比均显著变小（P<0.01），而叶片长宽比显著变大（P<0.01）。通过对小叶突变体和野生型‘ICPL81-3’杂交构建的F₂群体进行表型观察发现，不同单株的叶宽、叶长、长宽比和叶面积在F₂群体中均有较大变异，且显著相关，其中叶宽和叶面积呈现明显双峰分布，叶宽表型符合3∶1分离（X²2_0.05，1=3.84），表明小叶突变性状受隐性单基因控制。利用SSR标记和InDel标记结合混池分离群体分析法（Bulk segregation analysis，BSA）进行小叶基因初定位，获得在两个基因池内具有明显差异的1个InDel标记PA094，经基因池各单株检测和F₂群体单株检验，证实PA094和小叶突变性状具有稳定的连锁关系。研究结果为后续开展木豆小叶基因的精细定位及其基因克隆提供了重要基础。

关键词: 木豆, 小叶突变体, 表型鉴定, 遗传分析, 基因定位