Hybridization in Annual Plants: Patterns and Dynamics During a Four-Year Study in Mixed Rhinanthus Populations
Hybridization in Annual Plants: Patterns and Dynamics During a Four-Year Study in Mixed Rhinanthus Populations
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DOI：
10.1007/s12224-010-9077-2
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发表时间：
2010-12-01
影响因子：
1.2
通讯作者：
Wesselingh, Renate A.
中科院分区：
文献类型：
--
作者：
Ducarme, Veronique;Vrancken, Jerome;Wesselingh, Renate A.
一年生植物的杂交很罕见，但它们的短生活史为研究杂交动力学提供了极好的机会。杂交发生在一年生半寄生Rhinanthus minor和Rhinanthus angustifolius（列当科）之间。利用花的形态学，Kwak（1980）发现了与R.在一个单一的人口。我们的目标是发现这种模式是否也使用遗传标记，它是否通常发生在混合人群中，以及这些人群是否随时间推移而稳定。我们使用物种特异性遗传标记，以确定在一系列的混合类在三个不同年龄的混合种群在连续四年的个人数量。在幼龄群体中，第一年就出现了F-1代杂种，主要是R. minor和F（1）在第二年，但在以后的几年里，接近R的杂种。angustifolius变得更加丰富。我们在两个较老的种群中也发现了这一点，其中杂交种接近R。狭叶变种的出现频率总是高于与R. minor.随着时间的推移，R。狭叶藓在两个种群中的出现频率显著增加。标记存在和缺失的模式表明，高世代杂种主要是通过与其中一个亲本回交形成的，主要是R。当其在种群中的频率高于15%时，则为狭叶蕨。混合种群的动态取决于调节两个亲本物种存在的生态条件，以及渐渗到R。狭叶蕨似乎很普遍。
Hybridization in annual plants is rare, but their short life cycle provides an excellent opportunity to study the dynamics of hybridization. Hybridization occurs between the annual hemiparasites Rhinanthus minor and Rhinanthus angustifolius (Orobanchaceae). Using flower morphology, Kwak (1980) found a prevalence of hybrids close to R. angustifolius in a single population. We aim to find whether this pattern is also found using genetic markers, whether it is generally occurring in mixed populations, and whether these populations are stable over time. We used species-specific genetic markers to determine the number of individuals in a range of hybrid classes in three mixed populations of different ages during four consecutive years. In the young population, F-1 hybrids were found in the first year and mostly hybrids between R. minor and these F(1)s in the second year, but in the years after that, hybrids close to R. angustifolius became more abundant. We also found this in the two older populations, where hybrids close to R. angustifolius always occurred in higher frequencies than hybrids close to R. minor. Over time, R. angustifolius strongly increased in frequency in two populations. Patterns of marker presence and absence suggested that advanced-generation hybrids are mainly formed by backcrossing with one of the parents, predominantly R. angustifolius whenever its frequency in the population is higher than 15%. The dynamics of mixed populations depend on the ecological conditions that regulate the presence of the two parental species, and introgression into R. angustifolius seems prevalent.