EFFECTS OF COMPETITION ON THE FITNESS OF WILD AND CROP-WILD HYBRID SUNFLOWER FROM A DIVERSITY OF WILD POPULATIONS AND CROP LINES
EFFECTS OF COMPETITION ON THE FITNESS OF WILD AND CROP-WILD HYBRID SUNFLOWER FROM A DIVERSITY OF WILD POPULATIONS AND CROP LINES
复制标题
野生种群和作物品系多样性竞争对野生和作物野生杂交向日葵适应性的影响
DOI：
10.1554/06-020.1
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
R. Shaw
中科院分区：
文献类型：
--
作者：
K. Mercer;D. Wyse;R. Shaw
摘要由于作物基因组所赋予的特征，农田和野生种群之间的基因流动往往导致杂交后代与野生种群相比适合度降低。但作物-野生基因流动的进化结果的具体情况可能取决于环境，由于当地环境条件以及野生种群内部和野生种群之间以及作物品系之间的遗传变异而不同。为了评估F1杂交种适合度的上下文依赖性，将向日葵作物品系与来自美国北部的9个野生种群杂交。这些作物-野生杂交种和它们的野生杂交种是在有和没有小麦竞争的田间农业条件下种植的。杂交种的繁殖力远不如野生植物，但更有可能存活下来繁殖。野生种群之间的繁殖力有很大的差异，用于产生作物-野生杂交种的特定作物品系对繁殖力有显著影响。作物-野生杂交种的适合度因种群而异，来自三个不同作物品系的作物-野生杂交种的排名也不同。与杂交种相比，小麦竞争大大降低了野生植物的繁殖力和存活率，阻碍了野生植物的种子生产。基因型×环境互作表明，适合度对竞争的反应因群体而异。因此，杂交种相对于野生植物的适合度在不同的野生种群中差异很大，而且在不同的环境中也不一致。值得注意的是，在竞争条件下，杂交后代的相对适合度更高。这项研究是第一次证明作物-野生基因流动的后果取决于特定野生种群的遗传和当地的生物和非生物条件。
Abstract Gene flow between crop fields and wild populations often results in hybrids with reduced fitness compared to their wild counterparts due to characteristics imparted by the crop genome. But the specifics of the evolutionary outcome of crop-wild gene flow may depend on context, varying due to local environmental conditions and genetic variation within and among wild populations and among crop lines. To evaluate context-dependence of fitness of F1 hybrids, sunflower crop lines were crossed with nine wild populations from across the northern United States. These crop-wild hybrids and their wild counterparts were grown under agricultural conditions in the field with and without wheat competition. Hybrids were far less fecund than wild plants, yet more likely to survive to reproduce. There was considerable variability among wild populations for fecundity and the specific crop line used to generate the crop-wild hybrid significantly affected fecundity. The fitness deficit suffered by crop-wild hybrids varied by population, as did the rankings of the crop-wild hybrids from three different crop lines. Wheat competition decreased fecundity and survival considerably and hampered seed production of wild plants more than that of hybrids. Genotype × environment interactions indicated that the response of fitness to competition differed by population. Consequently, the fitness of hybrids relative to wild plants varied considerably among wild populations and was not consistent across environments. Notably, relative fitness of hybrids was greater under competitive conditions. This research is the first study of its kind to demonstrate that the consequences of crop-wild gene flow are context dependent and contingent on the genetics of the specific wild populations and the local biotic and abiotic conditions.