Lozada-Gobilard Sissi, Nielsen Nadine, Sapir Yuval
The Botanical Garden, School of Plant Sciences and Food Security, G.S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv 69978, Israel.
Biodiversity Unit, Department of Biology, Lund University, 223 62 Lund, Sweden.
Plants (Basel). 2023 Aug 18;12(16):2978. doi: 10.3390/plants12162978.
Flower traits, such as flower size or color changes, can act as honest signals indicating greater rewards such as nectar; however, nothing is known about shelter-rewarding systems. Large flowers of Royal irises offer overnight shelter as a reward to bees. A black patch might signal the entrance to the tunnel (shelter) and, together with the flower size, these might act as honest signals. We hypothesize that larger flowers and black patches indicate larger tunnels, and larger tunnels will increase pollinator visits, enhancing the plants' reproductive success. We measured seven species in a controlled environment and two species from three natural populations varying in flower size. Fruit and seed sets were assessed in these natural populations. We found a positive correlation between the flower, patch size, and tunnel volume, suggesting that the flowers and patch size act as honest signals, both under controlled conditions and in the wild. However, in natural populations, this positive relationship and its effect on fitness was population-specific. Flower size increased the fitness in YER , and interactions between flower/patch size and tunnel size increased the fitness in YER and NET populations. This suggests that the honesty of the signal is positively selected in these two populations. This study supports the hypothesis that pollinator-mediated selection leads to the honest signaling of flower advertisement.
花朵特征，如花朵大小或颜色变化，可作为诚实信号，表明有更大的回报，如花蜜；然而，对于提供庇护所的回报系统却一无所知。皇冠状鸢尾的大花为蜜蜂提供过夜庇护所作为回报。一个黑色斑块可能标志着隧道（庇护所）的入口，并且与花朵大小一起，这些可能作为诚实信号。我们推测较大的花朵和黑色斑块表明有更大的隧道，而更大的隧道会增加传粉者的来访，提高植物的繁殖成功率。我们在可控环境中测量了七个物种，并从三个自然种群中测量了两个花朵大小不同的物种。对这些自然种群的果实和种子结实情况进行了评估。我们发现花朵、斑块大小和隧道体积之间存在正相关，这表明在可控条件和野外环境中，花朵和斑块大小都作为诚实信号。然而，在自然种群中，这种正相关及其对适合度的影响因种群而异。花朵大小增加了YER种群的适合度，花朵/斑块大小与隧道大小之间的相互作用增加了YER和NET种群的适合度。这表明在这两个种群中，信号的诚实性受到了正向选择。这项研究支持了传粉者介导的选择导致花朵广告诚实信号这一假设。
