Field establishment of <i>Abies</i> stocktypes in Christmas tree plantations

Identification of stocktype attributes that speed up field establishment has potential to reduce rotation time of Christmas tree productions. Such morphological and physiological attributes can be targeted in the nursery production. This study tested the effects of container type and nursery seedling density on stocktype attributes at planting and the effects of these on field performance over two years in <i>Abies lasiocarpa</i> and <i>A. nordmanniana</i> Christmas tree stock. Nursery conditions had a considerable impact on seedling attributes at planting. Although sets of these correlated stocktype attributes contributed to forecast field performance, the predictive power was low. No simple relationships were found between plant biomass, stem diameter or height at planting and biomass at final harvest in either of the two species under the range of stocktype variation and field conditions tested. Contrary, stem diameter and stem height at planting explained some of the responses in stem diameter and height after two years in the field. Thus, any target seedling approach would have to be based on a combined set of stocktype attributes exploring more productive stocktypes. The differences observed between stocktypes were largely due to size differences and ontogenetic drift, and stocktypes converged towards a similar field phenotype over time.明确可加快田间定植的种苗(stocktype)性状，有望缩短圣诞树生产的轮作周期。这类形态与生理性状可作为育苗生产的选育目标。本研究以<i>Abies lasiocarpa</i>与<i>A. nordmanniana</i>圣诞树种苗为材料，探究了容器类型与育苗密度对定植时种苗性状的影响，以及上述性状对两年田间表现的作用。育苗环境对定植时的种苗性状具有显著影响。尽管多组相关的种苗性状可用于预测田间表现，但预测能力较低。在本次试验的种苗类型变异范围与田间条件下，两个物种的定植时植株生物量、茎粗或株高与最终收获时生物量之间均未发现简单关联。与之相反，定植时的茎粗与株高可部分解释两年田间种植后的茎粗与株高变化。因此，任何目标种苗选育方案都需基于多组种苗性状的综合考量，以筛选更具生产潜力的种苗类型。不同种苗类型间的差异主要源于初始大小差异与个体发育漂移，且随着时间推移，种苗类型的田间表型会逐渐趋同。