ECOLOGICAL AND GENETIC SPATIAL PATTERNS OF UROPHORA-CARDUI (DIPTERA, TEPHRITIDAE) AS EVIDENCE FOR POPULATION-STRUCTURE AND BIOGEOGRAPHICAL PROCESSES
ECOLOGICAL AND GENETIC SPATIAL PATTERNS OF UROPHORA-CARDUI (DIPTERA, TEPHRITIDAE) AS EVIDENCE FOR POPULATION-STRUCTURE AND BIOGEOGRAPHICAL PROCESSES
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DOI：
10.2307/5594
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发表时间：
1994-01-01
影响因子：
4.8
通讯作者：
BRANDL, R
中科院分区：
文献类型：
--
作者：
EBER, S;BRANDL, R
1. Urophora cardui 是一种植食性实蝇物种，可在蓟上产生明显的茎瘿。利用这些虫瘿可以很容易地绘制 U.cardui.2 的分布图。 U.cardui 在欧洲存在分布差距。先前的作者将这些差距归因于更新世以来未完成的重新移民。我们调查了巴伐利亚州东北部一个地区的生态和遗传空间格局，已知这种蝇类已经侵入了该地区的部分间隙。3。 U.cardui向这种分布间隙的范围扩张的平均年速率约为每年2公里，这远高于以前的一些研究的假设，并且与其他研究的结果一致。4．在研究区域的定殖部分内，50% 至 70% 的寄主植物斑块被卡杜伊氏菌占据。亚群规模通常很小，由寄生蜂引起的亚群死亡率可能达到 100%。平均寄生率从 1987 年的 28% 到 1991.5 年的 77%。 U.cardui 亚群的灭绝和空斑的定殖在研究区域内很常见，并且在调查期间均达到了 30% 左右。 6．卡杜伊氏菌在寄主植物斑块中的出现模式与记录的栖息地参数只有适度的相关性。发生的概率随着斑块大小的增加而增加。一年内我们发现了海拔的负面影响。瘿密度与邻近亚群密度呈正空间自相关，范围可达约 2 km。7。在 18 个可评分基因座中，只有 AAT 和 ACOH 被证明具有多态性并且可用于群体遗传区分。与胆密度数据相反，我们没有发现等位基因频率的空间模式。高速率的基因流动和单个个体的远距离分散可能会阻止局部遗传分化。尽管如此，我们发现单个等位基因频率与海拔高度之间存在相关性，这与生物地理尺度上的观察结果相匹配。8。我们将 U. cardui 系统解释为一个集合种群，其中恶劣的天气气候和寄生蜂会导致局部灭绝并影响定植率。9。我们关于范围扩张速率和气候因素影响的数据表明，实际的分布差距可能是由于历史时期的气候波动而不是更新世期间的气候波动造成的。
1. Urophora cardui is a phytophagous tephritid species that induces conspicuous stem galls on Cirsium arvense. Using these galls it is simple to map the distribution of U. cardui.2. U. cardui has distributional gaps in Europe. Previous authors ascribed these gaps to an unfinished re-immigration since the Pleistocene. We investigated the ecological and genetic spatial pattern in an area in north-eastern Bavaria, where this fly species is known to have invaded part of such a gap.3. The mean annual rate of range expansion of U. cardui into this distributional gap is about 2 km per year, which is much higher than postulated by some previous studies and consistent with results of others.4. Between 50 and 70% of host-plant patches are occupied by U. cardui within the colonized part of the study area. Subpopulation sizes are often quite small and mortality rates of subpopulations caused by parasitoids may reach 100%. Mean rates of parasitization range from 28% in 1987 to 77% in 1991.5. Extinctions of U. cardui subpopulations and colonizations of empty patches are common within the study area and both reached values around 30% during the years of investigation.6. The pattern of occurrence of U. cardui at host-plant patches is only modestly correlated with the recorded habitat parameters. The probability of occurrence increases with patch size. In one year we found a negative influence of altitude. Gall density shows a positive spatial autocorrelation with the density of neighbouring subpopulations up to a range of about 2 km.7. Out of 18 scorable loci, only AAT and ACOH proved to be polymorphic and useful for population genetic distinctions. Contrary to the gall density data, we found no spatial patterns of allele frequencies. High rates of gene flow with long-range dispersal of single individuals may prevent local genetic differentiation. Nevertheless, we found a correlation of single allele frequencies with altitude, which is matched by observations on a biogeographical scale.8. We interpret the U. cardui system as a metapopulation, where stressful weather climate and parasitoids cause local extinctions and affect colonization rate.9. Our data on the rate of range expansion and the influence of climatic factors suggest that the actual distributional gaps could be caused by temporary fluctuations of U. cardui based on climatic fluctuations in historical time rather than on climatic fluctuations during the Pleistocene.