Genetic divergence for physiological response to temperature between populations of a C3-C4 intermediate annual

Premise of research. Local adaptation ultimately arises as a result of adaptive divergence in phenotypic characters. Within a species, a large portion of the phenotypic traits that confer local adaptation must be physiological characters. Yet few studies consider adaptive divergence in physiological characters or estimate genetic variation within populations for physiological traits that may confer local adaptation. Here I test the hypothesis that there is genetic variation within and between populations of a C3-C4 intermediate for the CO2 compensation point (Γ) and other photosynthetic traits. In addition to local adaptation, population-level variation in photosynthetic characters of C3-C4 intermediates reflects the potential for evolution of more C4-like photosynthesis. Methodology. I chose two populations of Mollugo verticillata, one from a relatively cool climate and one from a warm climate. I quantified variation within and between populations by measuring photosynthetic physiol...研究前提：本地适应本质上源于表型性状的适应性分化。在同一物种内，赋予本地适应优势的表型性状中，有很大一部分为生理性状。然而目前鲜有研究关注生理性状的适应性分化，也未针对可能赋予本地适应优势的生理性状估算种群内的遗传变异。本研究验证如下假说：C3-C4中间型植物（C3-C4 intermediate）的种群内与种群间，存在与CO2补偿点（CO2 compensation point，Γ）及其他光合性状相关的遗传变异。除本地适应外，C3-C4中间型植物光合性状的种群水平变异，还反映了其向更接近C4途径的光合方式演化的潜力。 研究方法：本研究选取两个种群的轮叶粟米草（Mollugo verticillata），分别来自相对凉爽的气候区与温暖的气候区。通过测定光合生理指标以量化种群内与种群间的性状变异……