García C, Escribano-Ávila G
Plant Biology, CIBIO/InBio, Centro de Investigação em Biodiversidade e Recursos Genéticos, Laboratório Associado, Universidade do Porto, Campus Agrário de Vairão, 4485-661, Vairão, Portugal.
Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, c/Tulipán s/n, 28933, Móstoles, Spain.
J Plant Res. 2016 May;129(3):559-63. doi: 10.1007/s10265-016-0806-3. Epub 2016 Mar 4.
Genotyping of maternally derived seed tissues from georefered seeds that moved away from their source tree yield direct estimates of seed dispersal distances when the location and the genotype of the fruiting tree are available. These estimates are instrumental in forecasting the response of plant communities to drivers of global change, such as fragmentation or the expansion of invasive species. Obtaining robust assessments of seed dispersal distances requires comparing reliable multilocus genotypes of maternally derived seed tissues and fruiting trees, as previously shown for angiosperm species. However, robust estimates of seed dispersal distances based on direct methods are rare in non-model gymnosperms due to the difficulty in isolating high quality DNA from inconspicuous maternally derived seed tissues. These tissues tend to yield low DNA quantities that increase the frequency of genotyping errors. Here, we deliver a step-by-step visual protocol used to identify and isolate different seed tissues of interest for dispersal studies: embryos (2n, bi-parentally derived), seed coats (2n, maternally derived), and megagametophytes (n, maternally derived). We also provide an optimised lab protocol used to obtain multilocus genotypes from the target seed tissue. These broadly applicable protocols proved successful both in avoiding contamination among different seed tissues and providing reliable multilocus genotypes.
当结果树的位置和基因型已知时,对来自地理定位种子且已远离其源树的母本衍生种子组织进行基因分型,可直接估算种子传播距离。这些估算对于预测植物群落对全球变化驱动因素(如碎片化或入侵物种扩张)的响应至关重要。如之前在被子植物物种中所显示的那样,要获得对种子传播距离的可靠评估,需要比较母本衍生种子组织和结果树可靠的多位点基因型。然而,由于难以从不显眼的母本衍生种子组织中分离出高质量DNA,基于直接方法对非模式裸子植物种子传播距离进行可靠估算的情况很少见。这些组织往往产生少量DNA,从而增加了基因分型错误的频率。在这里,我们提供了一个逐步的可视化方案,用于识别和分离用于传播研究的不同感兴趣的种子组织:胚(2n,双亲衍生)、种皮(2n,母本衍生)和雌配子体(n,母本衍生)。我们还提供了一个优化的实验室方案,用于从目标种子组织中获得多位点基因型。这些广泛适用的方案在避免不同种子组织之间的污染以及提供可靠的多位点基因型方面都被证明是成功的。