Abstract:In this study, the full length cDNA of CCD8b was cloned from Musella lasiocarpa using RACE technique, and was designated as MlCCD8b (GenBank accession number MW013147),amino acid sequence alignment and phylogenetic tree were constructed. The expression patterns of MlCCD8b gene in different types and tissues of M. lasiocarpa were detected by realtime fluorescent quantitative PCR. The results showed that: (1) the full length cDNA was 2 052 bp, containing an ORF of 1 671 bp in length, encoding 556 amino acids. The relative molecular mass of coding protein is 61 574.26 Da and the isoelectric point is 6.61, which is a hydrophilic protein. This protein has a RPE65 conserved domain belonging to carotenoid oxygenase family. The subcellular localization most likely be on the thylakoid within chloroplast stroma.(2) Sequence comparison and phylogenetic tree analysis showed that the amino acid sequence of MlCCD8b had considerable similarity with those of other species, and had the closest evolutionary relationship with the CCD8b protein of Musa acuminata subsp. malaccensis and Ananas comosus. (3) Realtime PCR analysis showed that MlCCD8b exhibited a same tissue expression pattern between the two types of M. lasiocarpa, with the highest expression in rachis, followed by sucker growing point, root tip and leaf, the lowest expression or nonexpression in bract. (4) The expression of MlCCD8b in rachis, sucker growing point, root tip and leaf of RD05 were 4.47, 4.67, 2.09 and 1.10 times than those of YN01. (5) The 5DS content in RD05s root tip was 15.57 times than that in YN01s, which was consistent with the expression pattern of MlCCD8b. The study indicated that the MlCCD8b gene may participate in the synthesis and regulation of strigolactones. These results provided a basis for the further study on regulating the number of suckers in M. lasiocarpa using genetic engineering.