Abstract

 In this study, the differentiation of buds, inflorescences and flowers of the “Xiangfei” grapevine (Vitis vinifera L.) was examined, and the roles of the genes VvTFL1, VFL, VAP1, VvAG1 and VvSEP3 in the initiation and development of these organs were studied. We found that the structure of burst buds included an apical point, a leaf primordium, an inflorescence or tendril primordium, bract and stipule primordia. The original floral primordium formed lateral meristems for branching inflorescence primordia and continued to differentiate into floret primordia in lateral bud. VvTFL1 gene expression was detected in the apical meristems of swelling buds, but it was not detected during the entire process of inflorescence initiation and flower development. VFL and VAP1 genes were strongly detected in inflorescences and developing flowers. Furthermore, the VFL gene strongly detected in inflorescence meristems and flower organ primordia. VAP1 expression was detected in the branching of the pedicel region of burst buds, and after petal, stamen and carpel primordium development, VAP1 transcripts were clearly detected. The expression of VvAG1 and VvSEP3 began to be detected in the placental region of anatropous ovules at later stages of flower development, and VvAG1 had earlier effects than VvSEP3. These results suggest that those genes might play a different role in grapevine.

Key words: Grapevine, VvTFL1 gene, VFL gene, VAP1 gene, VvAG1 gene, VvSEP3 gene, bud, flower.