Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada.
Proc Biol Sci. 2011 Jul 7;278(1714):1989-96. doi: 10.1098/rspb.2010.1771. Epub 2010 Dec 8.
A plant's best strategy for acquiring resources may often depend on the identity of neighbours. Here, I ask whether plants adjust their strategy to local relatedness: individuals may cooperate (reduce competitiveness) with kin but compete relatively intensely with non-kin. In a greenhouse experiment with Ipomoea hederacea, neighbouring siblings from the same inbred line were relatively uniform in height; groups of mixed lines, however, were increasingly variable as their mean height increased. The reproductive yield of mixed and sibling groups was similar overall, but when adjusted to a common mean height and height inequality, the yield of mixed groups was significantly less. Where this difference in yield was most pronounced (among groups that varied most in height), mixed groups tended to allocate more mass to roots than comparable sibling groups, and overall, mixed groups produced significantly fewer seeds per unit mass of roots. These results suggest that, from the group perspective, non-kin may have wasted resources in below-ground competition at the expense of reproduction; kin groups, on the other hand, displayed the relative efficiency that is expected of reduced competitiveness.
植物获取资源的最佳策略通常可能取决于其邻居的身份。在这里，我想问的是植物是否会根据亲缘关系来调整其策略：个体可能与亲属合作（降低竞争力），但与非亲属竞争相对激烈。在温室实验中，用 Ipomoea hederacea 进行研究，来自同一自交系的相邻同胞在高度上相对均匀；然而，混合系的群体随着平均高度的增加而变得越来越多样化。混合和同胞群体的生殖产量总体上相似，但当调整到共同的平均高度和高度差异时，混合群体的产量明显较低。在产量差异最明显的地方（在高度差异最大的群体中），混合群体往往比可比的同胞群体分配更多的质量到根中，并且总体而言，混合群体每单位质量的根产生的种子数量明显较少。这些结果表明，从群体的角度来看，非亲属可能会在地下竞争中浪费资源，而牺牲繁殖；另一方面，亲缘关系群体表现出相对效率，这是预期的竞争力降低的结果。
