title: A single gene controls leaf background color in caladium (Araceae) and is tightly linked to genes for leaf main vein color, spotting and rugosity.
abstract: Modern cultivated caladiums (Caladium×hortulanum) are grown for their long-lasting and colorful leaves. Understanding the mode of inheritance for caladium leaf characteristics is critical for plant breeders to select appropriate parents, predict progeny performance, estimate breeding population sizes needed, and increase breeding efficiencies. This study was conducted to determine the mode of inheritance of two leaf background colors (lemon and green) in caladium and to understand their relationships with four other important leaf characteristics including leaf shape, main vein color, spotting, and rugosity. Seven caladium cultivars and three breeding lines were used as parents in 19 crosses, and their progeny were phenotyped for segregation of leaf traits. Results showed that the two leaf background colors are controlled by a single nuclear locus, with two alleles,LEMandlem, which control the dominant lemon and the recessive green leaf background color, respectively. The lemon-colored cultivar 'Miss Muffet' and breeding lines UF-52 and UF-53 have a heterozygous genotypeLEMlem. Chi-square tests showed that the leaf background color locusLEMis independent from the leaf shape locusF, but is tightly linked to three loci (S,VandRLF) controlling leaf spotting, main vein color, and rugosity in caladium. A linkage map that consists of four loci controlling major caladium leaf characteristics and extends ~15 cM was developed based on the observed recombination frequencies. This is the first report on the mode of inheritance of leaf background colors in caladium and in the Araceae family. The information gained in this study will be very useful for caladium breeding and study of the inheritance of leaf colors in other ornamental aroids, an important group of ornamental plants in the world.
authors.affiliation: Gulf Coast Research and Education Center, Department of Environmental Horticulture, IFAS, University of Florida , 14625 County Road 672, Wimauma, FL 33598, USA.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Cao
authors.affiliation: College of Horticulture and Landscape, Southwest University, Chongqing 400715, China; Visiting Scientist, Gulf Coast Research and Education Center, Department of Environmental Horticulture, IFAS, University of Florida, 14625 County Road 672, Wimauma, FL 33598, USA.
authors.forename: Shunzhao
authors.initials: S
authors.lastname: Sui
authors.affiliation: Gulf Coast Research and Education Center, Department of Environmental Horticulture, IFAS, University of Florida , 14625 County Road 672, Wimauma, FL 33598, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Gulf Coast Research and Education Center, Department of Environmental Horticulture, IFAS, University of Florida , 14625 County Road 672, Wimauma, FL 33598, USA.
authors.forename: Zhanao
authors.initials: Z
authors.lastname: Deng