Isolation of a Sequence Homolog to More Axillary Branches MAX2 Gene in Hibiscus rosa-sinensis and its use as Genetic Marker

Lateral branching plays an important role in the elaboration of adult plants architecture. Herein, we adopted a modified AFLP approach combined with a degenerate primer amplification to identify and isolate in the underinvestigated ornamental species H. rosasinensis an orthologous element of the MAX2 gene (More Axillary Branches), which acts downstream of the branching inhibition signaling pathway. A specific gene fragment was cloned and sequenced from nineteen H. rosa-sinensis cultivars and twelve Hibiscus botanical species and different significant nucleotide polymorphisms among genotypes that were observed. The comparative analysis revealed a high conservation of DNA sequences among cultivars and wild species sexually compatible with H. rosa-sinensis. The deduced amino acid sequences of the Hibiscus isolated fragments reveal four characteristic repeat regions showing high identity with other F-box/Leucine Reach Repeat MAX2 homologous sequences. The cloned fragment is a likely candidate gene to be validated for association with phenotype to release a gene-derived "perfect marker" for the compact habit trait.