Evolutionary response to herbivory: population differentiation in microsatellite loci, tropane alkaloids and leaf trichome density in Datura stramonium
Por:
De-la-Cruz, I. M., Cruz, L. L., Martinez-Garcia, L., Valverde, P. L., Flores-Ortiz, C. M., Hernandez-Portilla, L. B., Núñez-FarfáN J.
Publicada:
1 feb 2020
Ahead of Print:
1 dic 2019
Resumen:
It is thought that natural selection exerted by herbivores on plants has
promoted the evolution of plant traits that function as defence.
However, such selective pressures may vary spatially differentiating
populations in plant defence phenotypes. Yet, to ascertain the role of
natural selection on phenotypic differentiation between populations, it
is necessary to discard other evolutionary processes like genetic drift.
Evolutionary biologists have designed approaches to determine whether
population differentiation has been produced by natural selection in
contrast to random processes as a null hypothesis. To accomplish this,
we compare the magnitude of differentiation among populations in plant
defence against herbivores (selection) and in neutral loci (genetic
drift). Our study system is the plant Datura stramonium, whose
anti-herbivore defence includes tropane alkaloids and foliar trichomes,
and its specialized herbivorous insects. We selected two geographically
close natural populations of D. stramonium in Central Mexico and
estimated, under controlled conditions, population differentiation at
neutral loci (microsatellites) and defence traits (concentration of
tropane alkaloids and leaf trichome density). Results indicate very low
genetic differentiation at neutral loci between populations but strong
and significant phenotypic differentiation in putative defence traits.
The average values of tropane alkaloids and leaf trichome density were
higher in Ticuman than in Teotihuacan. Twelve out of 21 individual
tropane alkaloids were significantly more abundant in plants from
Ticuman, and the relative proportion of three of them contrasted
markedly. Thus, results point that differentiation between populations
of D. stramonium results from natural selection on defence traits.
Filiaciones:
De-la-Cruz, I. M.:
Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
Univ Nacl Autonoma Mexico, Dept Ecol Evolut, Inst Ecol, Mexico City, DF, Mexico
Cruz, L. L.:
Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
Univ Nacl Autonoma Mexico, Dept Ecol Evolut, Inst Ecol, Mexico City, DF, Mexico
Martinez-Garcia, L.:
Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
Univ Nacl Autonoma Mexico, Dept Ecol Evolut, Inst Ecol, Mexico City, DF, Mexico
Valverde, P. L.:
Departamento de Biología, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, Mexico
Univ Autonoma Metropolitana Iztapalapa, Dept Biol, Mexico City, DF, Mexico
Flores-Ortiz, C. M.:
Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlanepantla, Estado de México, Mexico
Univ Nacl Autonoma Mexico, Fac Estudios Super Iztacala, Tlalnepantla, Estado De Mexic, Mexico
Hernandez-Portilla, L. B.:
Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlanepantla, Estado de México, Mexico
Univ Nacl Autonoma Mexico, Fac Estudios Super Iztacala, Tlalnepantla, Estado De Mexic, Mexico
Núñez-FarfáN J.:
Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
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