Stam Remco, Scheikl Daniela, Tellier Aurélien
Section of Population Genetics, Technical University of Munich , Freising , Germany.
PeerJ. 2017 Jan 18;5:e2910. doi: 10.7717/peerj.2910. eCollection 2017.
Wild tomatoes are a valuable source of disease resistance germplasm for tomato () breeders. Many species are known to possess a certain degree of resistance against certain pathogens; however, evolution of resistance traits is yet poorly understood. For some species, like , both differences in habitat and within species genetic diversity are very large. Here we aim to investigate the occurrence of spatially heterogeneous coevolutionary pressures between populations of . We investigate the phenotypic differences in disease resistance within against three common tomato pathogens (, and a .) and confirm high degrees of variability in resistance properties between selected populations. Using generalised linear mixed models, we show that disease resistance does not follow the known demographic patterns of the species. Models with up to five available climatic and geographic variables are required to best describe resistance differences, confirming the complexity of factors involved in local resistance variation. We confirm that within , resistance properties against various pathogens show a mosaic pattern and do not follow environmental patterns, indicating the strength of local pathogen pressures. Our study can form the basis for further investigations of the genetic traits involved.
野生番茄是番茄育种者获取抗病种质的宝贵来源。已知许多物种对某些病原体具有一定程度的抗性；然而，抗性性状的进化仍知之甚少。对于某些物种，如，其栖息地差异和种内遗传多样性都非常大。在这里，我们旨在研究种群之间空间异质的协同进化压力的发生情况。我们研究了对三种常见番茄病原体（、和一种）的抗病性表型差异，并证实了所选种群之间抗性特性的高度变异性。使用广义线性混合模型，我们表明抗病性并不遵循该物种已知的种群统计学模式。需要多达五个可用的气候和地理变量的模型才能最好地描述抗性差异，这证实了局部抗性变异所涉及因素的复杂性。我们证实，在内部，针对各种病原体的抗性特性呈现出镶嵌模式，并不遵循环境模式，这表明了局部病原体压力的强度。我们的研究可为进一步研究相关遗传性状奠定基础。
