New insights into grapevine flowering

The study of grapevine (Vitis spp.) flowering has unique challenges owing to the unique shoot architecture of the plant and the arrest of the flowering process during winter. The grapevine flowering process: inflorescence number per vine, flower number per inflorescence, fruit set and growth has a major impact on fruitfulness ( berries per hectare) and hence yield. This review brings together past research into the biology and physiology of grapevine flowering with recent investigations of genes involved in flowering. Genes involved in floral induction and inhibition by gibberellins (GA insensitive), meristem identity ( LEAFY, TERMINAL FLOWER1) and organ identity (MADS-box genes) are discussed. An understanding of the function of key genes controlling the development of uncommitted primordia, floral induction and development, and fruit set in grapevine will provide new opportunities for improving vineyard fruitfulness. Understanding the grapevine floral genetic network will also offer insight into the different evolutionary strategies employed by plants to ensure reproduction.