COLDTREE project data on cold tolerance and dormancy assessments in pine and beech

Summarising, the objectives of the Coldtree project were: To identify novel physiological, and genetic techniques indicative of the onset of winter hardiness and dormancy in woody species and, using cDNA microarrays, to postulate a conceptual model describing the molecular events underlying these processes. To select a set of key genes, of which the expression patterns can be used to describe the stages of dormancy and hardiness. To evaluate the merits of these key genes as molecular diagnostic tool for nursery practice and improved forestation. Sustained yield from Europe's commercially exploited forests requires a supply of millions of seedlings annually. The planting stock for reforestation and urban horticulture, almost 1.7 billion tree seedlings and ornamental woody plants comprising a total value of about 2 billion Euro, is mainly produced by European forest tree nurseries. These nurseries rely on a tight scheduling of operations, to be able to deliver vital seedlings to the planting site. A critical step in a modern nursery production chain is the transfer of seedlings to cold or frozen storage. Cold storage is required to prevent winter damage, especially in containerised seedlings, to maintain planting stock in an inactive condition, and to ensure plant supply for geographically distinct planting sites, a requirement for large scaled or internationally operating nurseries. Indoor storage has therefore become common practice, but poses a new dilemma for nurserymen. Efficient management requires that the handling of seedlings, such as transfer to cold storage, be carried out at the earliest possible time. However, lifting and storage of insufficiently hardened plants reduces vitality and may lead to cold damage, dehydration and fungal infection. To prevent this kind of damage, and its adverse economic effects on nurseries and end-users, it is of vital importance to be able to determine accurately the peak physiological condition for lifting or transfer. Despite the economic importance of such decisions, nurserymen still predominantly rely on traditional (morphological) methods to identify this moment. Recently, several physiological measurement techniques have been proposed, and some of them have been used operationally. However, the number of nurseries in Europe utilising these techniques is limited, because the methods are either unreliable, labour intensive or technically demanding and the minimum test period (test dependent) can vary from 3 days to over 14 days. In nursery practice, where lifting opportunities can be severely limited by rainfall, frost and snow, such a delay may significantly reduce the number of plants lifted at peak physiological condition. In addition to the onset of dormancy, dormancy release is also of economic importance. If plants growing out in the nurseries are put into cold storage too late in spring, they show evidence of damage, particularly to the root system. In spring, plants start reversing the processes that protect them during winter before there is a visible sign of regrowth. So, efficient forestation and cost-effective nursery management require tools for rapid and reliable determination of the physiological condition of forest tree seedlings. To develop such tools, a thorough understanding of the cellular and molecular processes underlying cold hardiness is required. Unravelling the gene expression pattern as a seedling acquires the hardened state will reveal key processes that can be used as landmarks to describe the physiological condition of the tree. Eventually, this will result in molecular tests based on the presence or absence of specific messenger RNA's or proteins, that will allow a rapid evaluation of the physiological state and will facilitate forestation logistics. Such techniques are not yet available to forest tree nurseries and in this respect the forestry sector is lagging behind on horticulture and agriculture. See also "The application of cDNA microarray technology for unravelling molecular events underlying dormancy and cold hardiness in forest tree seedlings. (COLDTREE)" (attached) Attribution statement: Forest Research must be acknowledged as the source of the data in any subsequent papers/products.综上，Coldtree项目（Coldtree Project）的目标如下： 1. 鉴定可指示木本植物越冬耐寒性与休眠启动的新型生理及遗传技术，并借助cDNA微阵列（cDNA microarray）技术构建阐释上述过程背后分子事件的概念模型； 2. 筛选一组关键基因，其表达模式可用于表征休眠与耐寒性的不同阶段； 3. 评估这些关键基因作为苗圃生产与造林优化中分子诊断工具的应用价值。 欧洲商业化经营森林的可持续产能，每年需供应数以百万计的苗木。用于造林与城市园艺的种植材料——近17亿株林木苗木与观赏木本植物，总价值约20亿欧元——主要由欧洲林木苗圃培育。此类苗圃需严格把控作业时序，方能向种植基地交付健康活力的苗木。现代苗圃生产链中的关键环节之一，是将苗木转移至冷藏或冷冻储存环境。冷藏储存可避免苗木遭受冬季冻害（尤其针对容器苗），维持种植材料的休眠状态，并保障向不同地理区域的种植基地供苗——这也是规模化或跨国经营苗圃的必要需求。 因此，室内储存已成为常规操作，但也给苗圃经营者带来了新的难题。高效的管理要求苗木处理（如转移至冷藏库）需尽早开展。然而，对尚未充分耐寒驯化的苗木进行起苗与储存，会降低其活力，甚至引发冻害、脱水与真菌感染。为避免此类损害及其对苗圃与终端用户造成的经济损失，精准判断起苗或转移的最佳生理状态至关重要。 尽管此类决策具备重要经济价值，但苗圃经营者目前仍主要依赖传统（形态学）方法来判断这一节点。近年来，已有多项生理检测技术被提出，其中部分已投入实际应用。但欧洲采用此类技术的苗圃数量有限，原因在于这些方法要么可靠性不足、要么劳动强度高且技术门槛严苛，且最短检测周期（依检测方法而定）可从3天到14天以上不等。在苗圃实际生产中，起苗时机往往会因降雨、霜冻与降雪而大幅受限，如此长的检测延迟会显著降低在最佳生理状态下起苗的苗木数量。 除休眠启动外，休眠解除同样具备经济价值。若春季苗圃中培育的苗木过晚被移入冷藏库，则会出现受损症状，尤以根系损伤最为显著。春季，在可见的返青迹象出现前，苗木便会启动逆转冬季防寒机制的过程。 因此，高效造林与苗圃精细化管理，亟需能够快速、可靠检测林木苗木生理状态的工具。要开发此类工具，需充分解析耐寒性背后的细胞与分子机制。解析苗木获得耐寒驯化状态时的基因表达模式，可揭示可作为表征林木生理状态标志物的关键过程。最终，这将催生基于特定信使RNA（messenger RNA）或蛋白质表达与否的分子检测技术，实现对苗木生理状态的快速评估，并优化造林物流调度。目前此类技术尚未应用于林木苗圃，林业领域在这方面落后于园艺与农业产业。 另参阅附件《The application of cDNA microarray technology for unravelling molecular events underlying dormancy and cold hardiness in forest tree seedlings. (COLDTREE)》。归属声明：任何后续论文或产品中，均需注明Forest Research为该数据的来源方。