ABSTRACT
Interspeci‹c and intergeneric hybridization, often in combination with polyploidization, is the most important practice for the introduction of genetic variation in ornamental crops. Many of the cultivars of ornamental geophytes originated from complex species crosses that have given rise to a broad range of shapes and colors of plants and –owers (Benschop et al. 2010; Alstroemeria: Bridgen et al. 1989; Gladiolus: Ohri and Khoshoo 1983a,b; Hippeastrum: Meerow 2009; Lilium: Lim and
I. Introduction .......................................................................................................................... 131 II. Interspeci‹c Hybridization ................................................................................................... 132
A. Prefertilization Barriers .................................................................................................. 132 B. Postfertilization Barriers ................................................................................................ 132
III. Cytogenetics ......................................................................................................................... 133 A. Introduction .................................................................................................................... 133 B. Polyploidization .............................................................................................................. 134 C. Mitotic and Meiotic Polyploidization ............................................................................. 136 D. Introgression ................................................................................................................... 138 E. Haploidization ................................................................................................................. 140
IV. Breeding................................................................................................................................ 141 A. Development of Cultivar Assortment ............................................................................. 141
1. Lily ............................................................................................................................ 141 2. Tulip .......................................................................................................................... 143 3. Narcissus ................................................................................................................... 143 4. Hyacinth .................................................................................................................... 144 5. Other Ornamental Geophytes ................................................................................... 145
B. Current Breeding Objectives .......................................................................................... 145 1. Postharvest Quality and Flower Longevity ............................................................... 145 2. Low-Light and Low-Temperature Conditions ........................................................... 145 3. Disease Resistance .................................................................................................... 146
C. Mutation Breeding .......................................................................................................... 147 1. Sports: Natural Mutants ............................................................................................ 147 2. Radiation-Induced Mutations .................................................................................... 148 3. Somaclonal Variation ................................................................................................ 148
D. Molecular Breeding ........................................................................................................ 148 V. Concluding Remarks ............................................................................................................ 149 Chapter Contributors ...................................................................................................................... 149 References ...................................................................................................................................... 150
Van Tuyl 2006; Narcissus: Wylie 1952; Brandham 1986; Tulipa: Van Eijk et al. 1991; Zantedeschia: Snijder 2004).
