Darmency Henri, Menchari Yosra, Le Corre Valérie, Délye Christophe
INRA, UMR1347 Agroécologie, Dijon, 21000, France.
Evolution. 2015 Jan;69(1):271-8. doi: 10.1111/evo.12531. Epub 2014 Oct 29.
This article investigates the possible existence of mechanisms counterbalancing the negative pleiotropic effects on development and reproduction that are conferred by alleles responsible for herbicide resistance in the weed Alopecurus myosuroides. We considered three herbicide-resistant, mutant acetyl-coenzyme A carboxylase (ACCase) alleles, Leu1781, Asn2041, and Gly2078, found in eight resistant populations. Of these, Gly2078 is the only allele with a known fitness cost. We compared plants homozygous for wild-type ACCase alleles that were siblings of plants carrying a given mutant resistant ACCase allele with plants from three populations where resistance did not evolve. In each of two series of experiments, we measured germination dynamics, seedling vigor, plant height, vegetative biomass, and seed production. The wild-type siblings of plants carrying Gly2078 performed better in the field, on average, than wild-type plants that were sibling of plants carrying other mutant ACCase alleles, and particularly those carrying Leu1781. We propose that rapid evolution of the genetic background of plants from the populations where the Gly2078 allele originally arose could partially counterbalance Gly2078 fitness cost, enhancing the spread of the resistant genotypes.
本文研究了在杂草黑麦草中，是否存在能够抵消负责除草剂抗性的等位基因对发育和繁殖产生的负面多效性影响的机制。我们研究了在八个抗性种群中发现的三个抗除草剂的突变乙酰辅酶A羧化酶（ACCase）等位基因，即Leu1781、Asn2041和Gly2078。其中，Gly2078是唯一已知具有适合度代价的等位基因。我们将携带特定突变抗性ACCase等位基因的植物的野生型ACCase等位基因纯合的同胞植物，与来自三个未进化出抗性的种群的植物进行了比较。在两个系列的实验中，我们分别测量了发芽动态、幼苗活力、株高、营养生物量和种子产量。平均而言，携带Gly2078的植物的野生型同胞在田间的表现优于携带其他突变ACCase等位基因的植物的野生型同胞，尤其是携带Leu1781的那些。我们提出，Gly2078等位基因最初出现的种群中的植物遗传背景的快速进化可能会部分抵消Gly2078的适合度代价，从而增强抗性基因型的传播。
