Resistance to pre-dispersal seed predators in a natural hybrid zone
Resistance to pre-dispersal seed predators in a natural hybrid zone
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DOI：
10.1007/s00442-002-0900-1
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发表时间：
2002-05-01
期刊：
影响因子：
2.7
通讯作者：
Forbis, TA
中科院分区：
文献类型：
--
作者：
Campbell, DR;Crawford, N;Forbis, TA
植物杂交品种可以更多。更少。或者与它们的亲本物种相比，对食草动物有同样的抵抗力。这些抗性模式可能是植物杂交适合度的关键决定因素，也可能影响食草动物的分布。本文研究了自然杂交和实验杂交对一种预传播种子捕食者的抗性。这些物种及其杂交后代的主要区别在于避免水蝇产卵（双翅目：花蝇科）的能力，而不是减少发育中的幼虫对种子的损害。黄貂草的蝇卵出现频率最低，因此在避免伤害方面是最成功的。杂交种的抗性不是中等就是低于亲本种。因为这些模式在盆栽植物的实验阵列中持续存在，它们不能归因于杂交和亲本之间环境的持续差异。在实验阵列中，蝇卵的频率与花冠宽度呈正相关，花冠宽度是花大小的一个维度，也影响传粉率，这表明种子捕食者可以对杂交后代的生殖性状产生选择。此外。在其中一个阵列中，F2杂交种的产卵量超过了F1和亲本的平均水平。我们的研究结果强调，在评估植物对食草动物的反应时，需要考虑杂交种的遗传背景。
Plant hybrids can be more. less. or equally resistant to herbivores compared to their parental species. These patterns in resistance can be critical determinants of the fitness of plant hybrids and may also influence distribution of the herbivore. We examined resistance to a pre-dispersal seed predator by natural and experimental hybrids between Ipomopsis aggregata and I. tenuituba. These species and their hybrid offspring differed primarily in ability to avoid oviposition by Hylemya sp. (Diptera: Anthomyiidae) rather than in reducing damage to seeds by a developing larva. Plants of I. tenuituba had the lowest frequency of fly eggs and were thus the most successful at avoiding damage. Hybrids were either intermediate to or less resistant than both parental species. Because these patterns persisted in experimental arrays of interspersed potted plants, they cannot be attributed to ongoing differences in the environment between hybrid and parental sites. In experimental arrays, the frequency of fly eggs correlated positively with corolla width, a dimension of flower size that also influences the rate of pollination, suggesting seed predators can generate selection on reproductive traits of hybrids. Furthermore. in one of the arrays, oviposition on F2 hybrids exceeded the average for the F1 and the midparent. Our results underscore the need to consider genetic background of hybrids in assessing plant responses to herbivores.