Oberrath R, Böhning-Gaese Katrin
Institut für Zoologie/Tierphysiologie, RWTH Aachen, Kopernikusstrasse 16, D-52074 Aachen, Germany e-mail:
Oecologia. 1999 Nov;121(3):383-391. doi: 10.1007/s004420050943.
We studied the effect of floral color change on long- and short-distance attraction of insect pollinators to the herb lungwort, Pulmonaria collina. Lungwort flowers change color with age from red to blue. Young red flowers had a significantly greater pollen and nectar reward and were significantly more often unpollinated than old blue ones. Red and blue flowers both influenced long-distance attractiveness of plants, defined as the number of insect approaches towards an individual plant. After reaching a plant, flower visitors preferred to visit young red flowers. Therefore, short-distance attractiveness, defined as the number of flowers visited successively on an individual plant, was influenced mainly by the number of young red flowers. The co-occurrence of the change in reproductive ability, in amount of reward, and in flower color enabled lungwort plants to direct pollinators to reproductive, highly rewarding red flowers. The data suggest that by maintaining changed flowers lungwort plants can increase their long-distance attraction and simultaneously enhance the probability of flower visits to pre-changed flowers. Thus, we propose floral color change as a mechanism that can increase the efficiency of pollen transfer to enhance plant fitness.
我们研究了花色变化对传粉昆虫长距离和短距离吸引到草本植物肺草（Pulmonaria collina）的影响。肺草的花会随着年龄从红色变为蓝色。年轻的红色花朵具有显著更多的花粉和花蜜回报，并且与老的蓝色花朵相比，未授粉的情况显著更常见。红色和蓝色花朵都影响了植物的长距离吸引力，长距离吸引力定义为昆虫接近单株植物的次数。到达一株植物后，访花者更喜欢访问年轻的红色花朵。因此，短距离吸引力，定义为在单株植物上连续访问的花朵数量，主要受年轻红色花朵数量的影响。繁殖能力、回报量和花色变化的同时出现，使肺草植物能够将传粉者引向具有繁殖能力、回报丰厚的红色花朵。数据表明，通过保留变色的花朵，肺草植物可以增加其长距离吸引力，同时提高对变色前花朵的访花概率。因此，我们提出花色变化是一种可以提高花粉传播效率以增强植物适合度的机制。
