Despite the importance of Musa as a crop species, few genetic markers are available in banana and plantain due to the lack of research in transmission genetics (Ortiz and Vuylsteke 1994a). The major obstacles for Musa genetic analysis include: triploidy in most popular cultivars, the very low reproductive fertility, and the few hybrids recovered after in vitro embryo germination leading to small population sizes. Nonetheless, transmission genetic research was undertaken in Musa, particularly in the 1990s (Ortiz 2000). One of the fi rst Musa genetic research results was about fruit parthenocarpy and persistence of bracts and fl owers in the male

Department of Plant Breeding and Biotechnology, Swedish University of Agricultural Sciences, Box 101, SE-230 53, Alnarp, Sweden; e-mail: [email protected] List of abbreviations after the text.