A better understanding of regional differentiation and local adaptation of rare arable plants is essential for the development of suitable methods for the reintroduction of these species. We set up F1 and F2 greenhouse experiments with 4–12 source populations of five rare arable plant species to test for genetically based differentiation in biomass production and phenology in South Germany. For three species, i.e. Arnoseris minima, Consolida regalis and Teesdalia nudicaulis, reciprocal transplant experiments were performed in arable fields to investigate local adaptation in plant establishment as well as biomass production to the northern or southern regions of three seed transfer zones. We found low regional differentiation, but provenance-specific responses to drought stress in Legousia speculum-veneris biomass and A. minima phenology. Moreover, little evidence was identified for local adaptation, while significant differences were seen in the performance between the transplant sites and study years, indicating a high phenotypic variability. Our results suggest that the current seed zones are suitable for the seed transfer of rare arable plants in the study region. Thus, there is a low risk of maladaptation when using autochthonous seed sources within the seed zones, but a high extinction risk of these species and their respective ecosystem functions if no active restoration is done, including transplant measures.

对稀有耕地植物的区域分化和局部适应性的更好了解对于开发合适的方法来重新引入这些物种至关重要。我们建立了F1和F2温室实验，对5种稀有植物物种的4-12个源种群进行了测试，以测试德国南部生物量生产和物候方面的遗传差异。针对三个物种，即最小的Arnoseris，Consolida regalis和Teesdalia nudicaulis，在可耕地上进行了互惠移植实验，以调查植物在当地的适应性以及三个种子转移区北部或南部的生物量生产情况。我们发现区域分化程度低，但针对干旱胁迫的种源特定反应阔叶豆荚菌生物量和极小曲霉的物候学。此外，几乎没有证据表明局部适应，而移植部位和研究年份之间的表现却存在显着差异，这表明表型变异性很高。我们的结果表明，目前的种子区适合研究区域内稀有可耕植物的种子转移。因此，在种子区内使用本地种子资源时，适应不良的风险较低，但如果不采取积极措施，包括移植措施，则这些物种及其各自生态系统功能的灭绝风险就很高。