Abstract:In order to investigate the pollen abortion characteristics of Oncidium Honey Angel and reveal the regulation relationship between pollen abortion and OnMYB106 gene,this study used Oncidium Honey Angel (male sterile) and Oncidium Sharry Baby (fertile) as experimental materials to observe the morphology and characteristics of pollen clusters and pollen grains. In addition, based on the transcriptome analysis, a MYB transcription factor gene (OnMYB106) was cloned from Oncidium Honey Angel by RTPCR technique, and the relative expression of the gene was analyzed by qRTPCR. The results showed that: (1) the anther chambers of Oncidium Honey Angel was obviously flattened, and the outer walls were sunken and shrunk. (2) The contents of Oncidium Honey Angel pollen cells were missing and the cytoplasm was vacuolated. Its pollen grains were abnormal, the pollen wall was not continuous, and there were many holes (not germination holes). (3) The OnMYB106 gene contains an open reading frame of 819 bp that encodes 272 amino acids. Comparison between the cDNA and genomic DNA sequences showed that OnMYB106 gene contains three exons and two introns. (4) Bioinformatical analysis revealed that OnMYB106 belongs to the SANT superfamily and has two consecutive MYB DNAbinding domains. It is a typical R2R3MYB transcription factor. Phylogenetic tree analysis showed that OnMYB106 had the highest consistency with the MYB106 protein sequence of Sorghum bicolor, Oryza sativa and Brachypodium distachyon, and the evolutionary distance was the closest. (5) Quantitative real time PCR results showed that OnMYB106 was downregulated in the Oncidium Honey Angel pollen cluster. OnMYB106 was expressed in different tissues of Oncidium Honey Angel, with the highest expression in flowers and the lowest expression in pseudobulbs. In the flowering stage, the expression level of OnMYB106 was the highest in the bud peroid, and only a small amount in the blooming period. This study showed that the abnormal pollen wall development of Oncidium Honey Angel may lead to pollen abortion. The OnMYB106 gene may play an important regulatory role in the growth and development of floral organs, and this gene may belong to the “early” expression genes of pollen development, which mainly affects the formation of pollen wall of Oncidium Honey Angel.