IDENTIFICATION OF A RAPD MARKER LINKED TO SEX DETERMINATION IN THE BASKET WILLOW (SALIX-VIMINALIS L.)

In many dioecious plants, gender influences economic value, breeding s chemes, and/or opportunities for commercial use of genetically transfo rmed materials, The objective of this study was to identify molecular markers linked to sex determination loci in the dioecious plant Salix viminalis L, A 4 x 4 factorial mating design was used to identify sex ratios in full-sibling progeny, to generate a working genetics model f or segregating sex ratios, and to search for molecular markers linked to sex determination genes, Bulked segregant analysis, utilizing 380 a rbitrary decamer primers to generate randomly amplified polymorphic DN A (RAPD) products was initially applied to progeny sets from 3 of the 16 full-sibling families, Of the 1080 RAPD bands examined, only a sing le 560 bp band was shown to be linked to a sex determination locus, Th e same 560 bp band occurred in three additional full-sibling families and was present In one female parent and one male parent involved in t he factorial mating design, This marker, UBC354(560), is biparentally inherited, is associated with femaleness in certain genetic background s, and is linked to allele Al in the proposed two-locus epistatic gene tic model of sex determination for S. viminalis. Southern blots confir med marker homology among progeny and parents used in this study.