TY - JOUR
T1 - Flower color polymorphism maintained by overdominant selection in Sisyrinchium sp
AU - Takahashi, Yuma
AU - Takakura, Koh ichi
AU - Kawata, Masakado
N1 - Funding Information:
This study was partly supported by JSPS KAKENHI Grant No. 26650154.
Publisher Copyright:
© 2015, The Botanical Society of Japan and Springer Japan.
PY - 2015/9/9
Y1 - 2015/9/9
N2 - Negative frequency-dependent selection derived from positive frequency-dependent foraging is the best-known selection force maintaining genetic polymorphism within a population. However, in flowering plants, positive frequency-dependent foraging by pollinators is expected to accelerate the loss of low-frequency morphs by conferring a fitness advantage to the common morph, leading to monomorphism. In Japan, a non-native species, Sisyrinchium sp., exhibits conspicuous flower color polymorphism within a population comprising both purple morphs (homozygous recessive) and white morphs (heterozygous or homozygous dominant). Here we quantified genotype-specific reproductive success in order to reveal the contribution of overdominant selection on the maintenance of flower color polymorphism in this species. In artificial pollination experiments using individuals with identified genotypes, female reproductive success was higher in the heterozygote than in either homozygote. The frequency of purple morphs in natural populations (ca. 31 %) is similar to the frequency predicted by overdominant selection (25 %). Our results suggest that overdominant selection contributes to the maintenance of color morphs in the natural population of this species.
AB - Negative frequency-dependent selection derived from positive frequency-dependent foraging is the best-known selection force maintaining genetic polymorphism within a population. However, in flowering plants, positive frequency-dependent foraging by pollinators is expected to accelerate the loss of low-frequency morphs by conferring a fitness advantage to the common morph, leading to monomorphism. In Japan, a non-native species, Sisyrinchium sp., exhibits conspicuous flower color polymorphism within a population comprising both purple morphs (homozygous recessive) and white morphs (heterozygous or homozygous dominant). Here we quantified genotype-specific reproductive success in order to reveal the contribution of overdominant selection on the maintenance of flower color polymorphism in this species. In artificial pollination experiments using individuals with identified genotypes, female reproductive success was higher in the heterozygote than in either homozygote. The frequency of purple morphs in natural populations (ca. 31 %) is similar to the frequency predicted by overdominant selection (25 %). Our results suggest that overdominant selection contributes to the maintenance of color morphs in the natural population of this species.
KW - Color polymorphism
KW - Heterozygote advantage
KW - Overdominant selection
KW - Reward-bearing flowers
KW - Sisyrinchium
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U2 - 10.1007/s10265-015-0750-7
DO - 10.1007/s10265-015-0750-7
M3 - Article
C2 - 26354759
AN - SCOPUS:84946500857
VL - 128
SP - 933
EP - 939
JO - Journal of Plant Research
JF - Journal of Plant Research
SN - 0918-9440
IS - 6
ER -