Vitisflower types: from the wild to crop plants

Abstract

Vitis viniferacan be divided into two subspecies,V. viniferasubsp.vinifera, one of the most important agricultural crops in the world, and its wild ancestor,V. viniferasubsp.sylvestris. Three flower types can be observed: hermaphrodite and female (on some varieties) invinifera, and male or female flowers insylvestris. It is assumed that the different flower types in the wild ancestor arose through specific floral patterns of organ abortion. A considerable amount of data about the diversity of sexual systems in grapevines has been collected over the past century. Several grapevine breeding studies led to the hypothesis that dioecy inviniferais derived from a hermaphrodite ancestor and could be controlled by either, one or two linked genetic determinants following Mendelian inherence. More recently, experiments using molecular approaches suggested that theselociwere located in a specific region of the chromosome 2 ofvinifera. Based on the works published so far, its seems evident that a putative sexlocusis present in chromosome 2. However, it is still not fully elucidated whether flower types are regulated by two linkedlocior by onelocuswith three alleles. Nevertheless, several genes could contribute to sex determination in grapevine. This review presents the results from early studies, combined with the recent molecular approaches, which may contribute to the design of new experiments towards a better understanding of the sex inheritance in grapevine.