Institute of Earth and Environmental Sciences, University of Freiburg, Freiburg, Germany; Institute of Ecology, Leuphana University, Germany.
Plant Biol (Stuttg). 2015 Jan;17(1):201-8. doi: 10.1111/plb.12180. Epub 2014 Apr 14.
Pollination is critical to fruit production, but the interactions of pollination with plant resources on a plant's reproductive and vegetative features are largely overlooked. We examined the influences of pollination, irrigation and fertilisation on the performance of almond, Prunus dulcis, in northern California. We used a full-factorial design to test for the effects of pollination limitation on fruit production and foliage variables of whole trees experiencing four resource treatments: (i) normal water and nutrients, (ii) reduced water, (iii) no nutrients, and (iv) reduced water and no nutrients. In each of these combinations, we applied three pollination treatments: hand-cross pollination, open-pollination and pollinator exclusion. Pollination strongly affected yield even under reduced water and no nutrient applications. Hand-cross pollination resulted in over 50% fruit set with small kernels, while open-pollinated flowers showed over 30% fruit set with moderate-sized kernels. Pollinator-excluded flowers had a maximum fruit set of 5%, with big and heavy kernels. Reduced water interacted with the open- and hand-cross pollination treatments, reducing yield more than in the pollinator exclusion treatment. The number of kernels negatively influenced the number of leaves, and reduced water and no nutrient applications interacted with the pollination treatments. Overall, our results indicate that the influences of pollination on fruit tree yield interact with the plant availability of nutrients and water and that excess pollination can reduce fruit quality and the production of leaves for photosynthesis. Such information is critical to understand how pollination influences fruit tree performance.
授粉对果实生产至关重要，但授粉与植物资源在植物生殖和营养特征上的相互作用在很大程度上被忽视了。我们研究了授粉、灌溉和施肥对加利福尼亚北部杏仁（Prunus dulcis）性能的影响。我们使用完全因子设计来测试授粉限制对经历四种资源处理的整棵树的果实产量和叶片变量的影响：（i）正常的水和养分，（ii）减少的水，（iii）没有养分，以及（iv）减少的水和没有养分。在这些组合中的每一种，我们应用了三种授粉处理：人工授粉、自然授粉和传粉者排除。即使在减少水和没有养分的应用下，授粉也强烈影响产量。人工授粉导致超过 50%的果实结实，核小，而自然授粉的花朵有超过 30%的果实结实，核中等大小。传粉者排除的花朵的果实结实率最高为 5%，核大而重。减少的水与自然授粉和人工授粉处理相互作用，比传粉者排除处理减少了更多的产量。核的数量与叶片的数量呈负相关，减少的水和没有养分的应用与授粉处理相互作用。总的来说，我们的结果表明，授粉对果树产量的影响与植物养分和水分的可用性相互作用，过量授粉会降低果实质量和光合作用的叶片生产。这些信息对于理解授粉如何影响果树性能至关重要。
