DEVELOPMENT OF GENIC MALE-STERILE WATERMELON LINES WITH DELAYED-GREENSEEDLING MARKER

Hybrid seed production can be facilitated by using male sterility coup led with a seedling marker, This research was initiated to combine the ms male sterility and dg delayed-green seedling marker into watermelo n [Citrullus lanatus (Thunb,) Matsum. & Nakai] lines, Male-sterile pla nts of the male-sterile line G17AB were crossed with plants of delayed -green breeding line Pale90, which has yellow cotyledons and pale-gree n, newly developed, true leaves, The double-recessive recombinants, ma le sterile and delayed green, from the F-2 population were backcrossed to the male-fertile plants of G17AB, The pedigree method was used for selection in the progenies, The segregation ratios obtained from F-2 and BC1F2 populations suggest that the male-sterile and delayed-green traits are inherited independently and that delayed green is inherited as a single recessive nuclear gene, Two male-sterile watermelon lines with delayed-green seedling marker have been developed, These lines w ill provide a convenient way to introduce male sterility and the delay ed-green seedling marker into various genetic backgrounds, These two l ines can be used for testing the efficiency of a new, hybrid, watermel on, seed production system.