Demonstration of local adaptation in maize landraces by reciprocal transplantation

Populations are locally adapted when they exhibit higher fitness than foreign populations in their native habitat. Maize landrace adaptations to highland and lowland conditions are of interest to researchers and breeders. To determine the prevalence and strength of local adaptation in maize landraces, we performed a reciprocal transplant experiment across an elevational gradient in Mexico. We grew 120 landraces, grouped into four populations (Mexican Highland, Mexican Lowland, South American Highland, South American Lowland), in Mexican highland and lowland common gardens and collected phenotypes relevant to fitness and known highland-adaptive traits such as anthocyanin pigmentation and macrohair density. 67k DArTseq markers were generated from field specimens to allow comparison between phenotypic patterns and population genetic structure.
We found phenotypic patterns consistent with local adaptation, though these patterns differ between the Mexican and South American populations. Quan...

当种群在原生栖息地的适合度高于外来种群时，即表明其已发生局部适应（local adaptation）。玉米地方品种对高低海拔环境的适应性一直受到研究者与育种家的关注。为明确玉米地方品种局部适应的普遍性与强度，我们在墨西哥沿海拔梯度（elevational gradient）开展了互植实验（reciprocal transplant experiment）。我们将120个地方品种划分为四个种群（墨西哥高海拔、墨西哥低海拔、南美高海拔、南美低海拔），在墨西哥高低海拔的公共试验园（common gardens）中种植，并收集了与适合度相关的表型（phenotypes），以及已知的高海拔适应性性状（如花青素着色（anthocyanin pigmentation）和粗毛密度（macrohair density））。我们从田间样本中生成了67k个DArTseq标记（DArTseq markers），以用于比较表型模式与种群遗传结构（population genetic structure）。我们发现表型模式与局部适应相符，尽管墨西哥种群与南美种群的模式存在差异。Quan...