In Switzerland, chestnut forests cover about 27,100 ha, plus some 6800 ha of mixed stands. Due to environmental and historical reasons, most of these still existing forests are located in the Swiss Southern Alps, whereas in the northern parts of the country the chestnut cultivation and the related knowledge strongly regressed since the Little Ice Age period. Nevertheless, Switzerland still hosts valuable genetic resources of the sweet chestnut tree. The present genetic study bases on a nationwide inventory, identification and precise localisation of old and/or grafted chestnut trees for conservation purposes. The main objectives were: (1) to evaluate the genetic diversity and the genetic structure of Castanea sativa in Switzerland, and (2) to define a program of conservation including the proposal of a defined core collection. We genetically analysed a pre-selection of 962 accessions (out of 14,165 inventoried trees throughout Switzerland), profiling them with 24 microsatellites. We identified 675 different genotypes out of 962 accessions with a 29.8% of repetitiveness due to clonality. A structural analysis based on a Bayesian method allowed to identify two main clusters, one mostly related to the genetic group from southern Europe (Reconstructed Panmictic Population RPP1) and a second one (RPP2) which revealed to be independent and genetically different from other European groups of chestnut cultivars. The Swiss RPP2 represents a new genetic group, and consequently a complement to genetic resources of chestnut tree in Europe. Genetic analysis allowed defining a core collection of 46 genotypes, which should be used in priority for the Swiss conservation program.

在瑞士，板栗林占地约27,100公顷，加上约6800公顷的混交林。由于环境和历史原因，这些仍然存在的森林大多数位于瑞士南部的阿尔卑斯山，而在该国北部，自小冰河时期以来，栗子的种植和相关知识已大量退化。尽管如此，瑞士仍然拥有甜栗树的宝贵遗传资源。当前的遗传研究基于全国范围内的清单，为了保护目的，对老和/或嫁接的栗树进行了鉴定和精确定位。主要目的是：（1）评估栗木的遗传多样性和遗传结构。（2）制定保护计划，包括提出明确的核心收藏的建议。我们对962份种质进行了预选分析（在整个瑞士的14,165棵清单上的树木中），并用24个微卫星对它们进行了分析。我们从962个种质中鉴定出675种不同的基因型，其中29.8％的重复性归因于克隆性。基于贝叶斯方法的结构分析可以确定两个主要聚类，一个主要与南欧的遗传群体相关（重建的泛滥种群RPP1），第二个聚类（RPP2）与其他欧洲群体独立且在遗传上有所不同板栗品种。瑞士RPP2代表了一个新的遗传群体，因此是欧洲板栗树遗传资源的补充。