Adaptive introgression in hybrid swarms between wild and domesticated barley in Israel

以色列野生大麦和驯化大麦之间杂交群体的适应性渗入

• 批准号: 460265804
• 负责人: Dr. Martin Mascher, Ph.D.
• 金额: --
• 依托单位: Abteilung Züchtungsforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/460265804?language=en
• 关键词: Adaptive; introgression; hybrid; swarms; between

Plant domestication has occurred very recently on a phylogenetic timescale. Hence, crop plants are often interfertile with their wild progenitors. In regions, where wild and domesticated plants co-occur, hybridization can happen. If crop-wild geneflow – in either direction – confers fitness benefits, it can give rise to hybrid swarms that harbor, for instance, in a wild background beneficial alleles donated from a crop introgressor. Barley (Hordeum vulgare L.) is an important crop species, whose domestication process has been intensely studied at the archaeological, genetic and molecular level. In past decades, botanists have observed “six-rowed wild barley”, i.e. wild-growing barley showing three fertile florets per inflorescence node, a hallmark trait of domesticated barley. There are several avenues to bring about these intermediate forms: (i) hybridization between wild and domesticated types; (ii) de novo mutation of domestication genes; (iii) de-domestication by genetic recombination. Our preliminary sequence data of three six-rowed wild barley populations in Israel support the presence of hybrid swarms showing domesticated haplotypes in an otherwise wild genomic background, and motivate the hypothesis of adaptive introgression of domesticated SIX ROWED SPIKE (Vrs1) alleles into weedy wild barley. To test this hypothesis, we will conduct the following experiments and analyses: (i) population genomic analyses of newly collected six-rowed wild barleys from Israel and sympatric two-rowed genotypes to detect genomic footprints of crop-wild gene-flow; (ii) eco-physiological experiments to understand the fitness consequence of a six-rowed phenotype in weedy barley; and (iii) genetic mapping of traits associated with weediness in experimental populations to identify genetic factors involved in adaptation of wild plants to agricultural environment. Taking advantage of a well-studied model of plant domestication amenable to genetic studies, our research will shed light on adaptation processes that help wild plants thrive in man-made habitats.

植物驯化在系统发育时间尺度上最近才发生。因此，农作物常常与其野生祖先杂交。在野生和驯化植物共存的地区，可能会发生杂交。如果作物野生基因流（无论向哪个方向）带来健康益处，它就可以产生杂交群体，例如，在野生背景中蕴藏着作物基因渗入者捐赠的有益等位基因。大麦（Hordeum vulgare L.）是一种重要的农作物物种，其驯化过程在考古、遗传学和分子水平上得到了深入研究。在过去的几十年里，植物学家观察到“六棱野生大麦”，即野生大麦的每个花序节上显示出三朵可育的小花，这是驯化大麦的标志性特征。有几种途径可以产生这些中间形式：（i）野生和驯化类型之间的杂交； (ii) 驯化基因的从头突变； (iii) 通过基因重组进行去驯化。我们对以色列三个六行野生大麦群体的初步序列数据支持了在野生基因组背景中显示驯化单倍型的杂交群体的存在，并激发了驯化六行穗状花序（Vrs1）等位基因适应性渗入杂草野生大麦的假设。为了检验这一假设，我们将进行以下实验和分析：（i）对从以色列新收集的六行野生大麦和同域两行基因型进行群体基因组分析，以检测作物野生基因流的基因组足迹； (ii) 生态生理学实验，以了解杂草大麦六行表型的适应性结果； (iii) 对实验种群中与杂草相关的性状进行遗传图谱分析，以确定野生植物适应农业环境所涉及的遗传因素。利用经过充分研究的适合遗传学研究的植物驯化模型，我们的研究将揭示帮助野生植物在人造栖息地中茁壮成长的适应过程。