Genetic basis of transgressive segregation in rice heading phenotypes

Transgressive segregation produces hybrid progeny phenotypes that exceed parental phenotypes. Unlike heterosis, extreme phenotypes caused by transgressive segregation are heritably stable. We examined transgressive phenotypes of flowering time in rice. Our previous study examined days to flowering (...

Full description

Saved in:
Bibliographic Details
Published inbioRxiv
Main Authors Koide, Yohei, Uchiyama, Takashi, Ota, Yuya, Sakaguchi, Shuntaro, Tezuka, Ayumi, Nagano, Atsushi J, Ishiguro, Seiya, Takamure, Itsuro, Kishima, Yuji
Format Paper
LanguageEnglish
Published Cold Spring Harbor Cold Spring Harbor Laboratory Press 31.01.2018
Subjects
Alleles
Cultivars
Epistasis
Flowering
Gene loci
Gene polymorphism
Genetic analysis
Genomes
Genotype & phenotype
Heterosis
Phenotypes
Quantitative trait loci
Single-nucleotide polymorphism
Online AccessGet full text

Cover

More Information
Summary:Transgressive segregation produces hybrid progeny phenotypes that exceed parental phenotypes. Unlike heterosis, extreme phenotypes caused by transgressive segregation are heritably stable. We examined transgressive phenotypes of flowering time in rice. Our previous study examined days to flowering (heading; DTH) in six F2 populations for which the parents had distal DTH, and found very few transgressive phenotypes. Here, we demonstrate that transgressive segregation in F2 populations occurred between parents with proximal DTH. DTH phenotypes of the A58 Kitaake F2 progenies frequently exceeded those of both parents. Both A58 and Kitaake are japonica rice cultivars adapted to Hokkaido, Japan, which is a high-latitude region, and have short DTH. Among the four known loci required for short DTH, three loci had common alleles in A58 and Kitaake, and only the one locus had different alleles. This result indicates that there is a similar genetic basis for DTH between the two varieties. We identified five new quantitative trait loci (QTLs) associated with transgressive DTH phenotypes by genome-wide single nucleotide polymorphism (SNP) analysis. Each of these QTLs showed different degrees of additive effects on DTH, and two QTLs had epistatic effect on each other. These results demonstrated that genome-wide SNP analysis facilitated detection of genetic loci associated with the extreme phenotypes and revealed that the transgressive phenotypes were produced by exchanging complementary alleles of a few minor QTLs in the similar parental genotypes.
DOI:10.1101/257766