Plant mitochondria and plastids display an array of inheritance patterns and varying levels of heteroplasmy, where individuals harbor more than one version of a mitochondrial or plastid genome. Organelle inheritance in plants has the potential to be quite complex and can vary with plant growth, development, and reproduction. Few studies have sought to investigate these complicated patterns of within individual variation and inheritance using experimental crosses in plants. We carried out crosses in carrot, Daucus carota L. (Apiaceae), which has previously been shown to exhibit organellar heteroplasmy. We used mitochondrial and plastid markers to begin to disentangle the patterns of organellar inheritance and the fate of heteroplasmic variation, with special focus on cases where the mother displayed heteroplasmy. We also investigated heteroplasmy across the plant, assaying leaf samples at different development stages and ages. Mitochondrial and plastid paternal leakage was rare and offspring received remarkably similar heteroplasmic mixtures to their heteroplasmic mothers, indicating that heteroplasmy is maintained over the course of maternal inheritance. When offspring did differ from their mother, they were likely to exhibit a loss of the genetic variation that was present in their mother. Finally, we found that mitochondrial variation did not vary significantly over plant development, indicating that substantial vegetative sorting did not occur. Our study is one of the first to quantitatively investigate inheritance patterns and heteroplasmy in plants using controlled crosses, and we look forward to future studies making use of whole genome information to study the complex evolutionary dynamics of plant organellar genomes.

中文翻译：

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解开植物细胞器基因组的复杂遗传模式：以胡萝卜为例

植物线粒体和质体显示出一系列遗传模式和不同水平的异质性，其中个体拥有不止一个版本的线粒体或质体基因组。植物中的细胞器遗传可能非常复杂，并且会随着植物的生长、发育和繁殖而变化。很少有研究试图使用植物中的实验杂交来研究这些复杂的个体变异和遗传模式。我们在胡萝卜中进行了杂交，Daucus carota L.（伞形科），此前已证明其表现出细胞器异质性。我们使用线粒体和质体标记开始解开细胞器遗传的模式和异质变异的命运，特别关注母亲表现出异质性的情况。我们还研究了整个植物的异质性，分析了不同发育阶段和年龄的叶样本。线粒体和质体父本渗漏很少见，后代收到的异质混合物与其异质母体非常相似，表明异质性在母体遗传过程中得以维持。当后代确实与他们的母亲不同时，他们很可能会表现出他们母亲身上存在的遗传变异的丧失。最后，我们发现线粒体变异在植物发育过程中没有显着变化，表明没有发生大量的营养分类。我们的研究是最早使用受控杂交定量研究植物遗传模式和异质性的研究之一，