Higher Levels of Multiple Paternities Increase Seedling Survival in the Long-Lived Tree Eucalyptus gracilis

The dataset aims at studying associations between mating system parameters and fitness in natural populations of trees. Fifty-eight open-pollinated progeny arrays were collected from trees in three populations. Progeny were planted in a reciprocal transplant trial. Fitness was measured by family establishment rates. We genotyped all trees and their progeny at eight microsatellite loci. Planting site had a strong effect on fitness, but seed provenance and seed provenance × planting site did not. Populations had comparable mating system parameters and were generally outcrossed, experienced low biparental inbreeding and high levels of multiple paternity. As predicted, seed families that had more multiple paternities also had higher fitness, and no fitness-inbreeding correlations were detected. Demonstrating that fitness was most affected by multiple paternities rather than inbreeding, we provide evidence supporting the constrained inbreeding hypothesis; i.e. that multiple paternity may impact on fitness over and above that of inbreeding, particularly for preferentially outcrossing trees at life stages beyond seed development. This dataset could potentially be reused for meta-analysis or review of effects of habitat fragmentation on plants (e.g. pollination, mating system, genetic diversity etc). Please contact owner prior to re-use.
This is part of the authors' PhD at the University of Adelaide, supervised by Prof Andrew Lowe, Dr Mike Gardner and Dr Kym Ottewell. Main goals of the project were 1. Examine and quantify the impact of fragmentation and tree density on mating patterns, and how this may vary with pollinators of differing mobility 2. Determine the theoretical expectations and perform empirical tests of mating pattern-fitness relationships in trees 3. Explore the plant genetic resource management implications that arise from the observations in aims 1 and 2

本数据集旨在探究树木自然种群中交配系统参数与适合度之间的关联。研究人员从3个自然种群的亲本树木中采集了58个开放授粉子代株系（open-pollinated progeny arrays），将子代材料开展互惠移植试验（reciprocal transplant trial），并以家系定植率作为适合度的衡量指标。研究人员对所有亲本树木及其子代的8个微卫星位点（microsatellite loci）进行了基因分型分析。结果显示，种植位点对适合度存在显著影响，但种子种源以及种子种源与种植位点的交互作用均无显著效应。各供试种群的交配系统参数较为相近，整体以异交为主，仅存在较低水平的双亲近交（biparental inbreeding），且多父本（multiple paternity）发生比例较高。正如研究预期，多父本比例更高的种子家系其适合度也显著更高，未检测到适合度与近交水平之间的相关性。本研究证实，适合度主要受多父本而非近交水平调控，为约束近交假说（constrained inbreeding hypothesis）提供了实证支持；即多父本对适合度的影响可能超出近交的作用，尤其对于偏好异交的树木，在种子发育之后的生命阶段更为显著。本数据集可用于植物生境破碎化效应的荟萃分析或综述研究（例如授粉、交配系统、遗传多样性等方向），如需二次使用，请先联系数据集所有者。
本研究为作者在阿德莱德大学（University of Adelaide）完成的博士学位工作，由Andrew Lowe教授、Mike Gardner博士以及Kym Ottewell博士指导。本项目的核心研究目标包括：1. 检验并量化生境破碎化与树木密度对交配模式的影响，以及该影响如何随传粉者移动能力的差异而变化；2. 明确树木交配模式与适合度关联的理论预期，并开展相关实证检验；3. 基于目标1和2的观测结果，探索其衍生的植物遗传资源管理启示。