Raabová J, Münzbergová Z, Fischer M
Department of Botany, National Museum, Průhonice, Czech Republic.
Plant Biol (Stuttg). 2009 Nov;11(6):829-36. doi: 10.1111/j.1438-8677.2008.00186.x.
Crosses between plants from different populations may result in heterosis or outbreeding depression. However, despite its importance for conservation, little is known about the spatial scale over which these effects may arise. To investigate the consequences of between-population crosses at two distinct spatial scales, we conducted reciprocal crosses between four populations from two regions in the rare perennial herb Aster amellus. We assessed seed set and offspring fitness in a common garden experiment. Overall, between-population crosses within regions (10 km) resulted in 8% lower seed set than within-population crosses, while between-region crosses (70 km) resulted in 17% higher seed set than within-population crosses. Moreover, offspring from between-population crosses produced 18% more flower heads than offspring from within-population crosses. We conclude that hybridisation between A. amellus plants from different populations did not lead to immediate outbreeding depression and, thus, could represent a valid conservation option to increase genetic diversity. Moreover, our results suggest that the distance between populations affects the outputs of between-population crosses and therefore needs to be taken into account when promoting gene flow between populations.
来自不同种群的植物杂交可能会导致杂种优势或远交衰退。然而，尽管其对保护工作很重要，但对于这些影响可能出现的空间尺度却知之甚少。为了研究在两个不同空间尺度上种群间杂交的后果，我们对珍稀多年生草本植物紫菀（Aster amellus）两个区域的四个种群进行了正反交。我们在一个共同花园实验中评估了结实率和后代适合度。总体而言，区域内（10公里）的种群间杂交导致结实率比种群内杂交低8%，而区域间杂交（70公里）导致结实率比种群内杂交高17%。此外，种群间杂交的后代比种群内杂交的后代产生的头状花序多18%。我们得出结论，紫菀不同种群的植株之间杂交并未导致直接的远交衰退，因此，可以作为增加遗传多样性的一种有效的保护选择。此外，我们的结果表明，种群间的距离会影响种群间杂交的结果，因此在促进种群间基因流动时需要考虑这一点。
