Olsen Kenneth M, Schaal Barbara A
Mol Ecol. 2007 Jul;16(14):2838-40. doi: 10.1111/j.1365-294X.2007.03359.x.
The opportunity for gene flow between a vegetatively propagated crop and its wild relatives is expected to be much lower than for seed-propagated crops, since sexual reproduction in the crop occurs only infrequently. A study by Duputié and colleagues now demonstrates evidence of sexual reproduction between a vegetatively propagated crop and a closely related wild congener. Working in French Guiana, these workers have documented a hybrid zone arising from introgression between cassava (Manihot esculenta ssp. esculenta, Euphorbiaceae), which is propagated by stem cuttings, and wild Manihot populations growing in close proximity. Patterns of heterozygosity suggest that there are little-to-no barriers to reproduction between the crop and these wild populations. Previous work by these researchers has documented the importance of occasional sexual reproduction for the development of cassava varieties in traditional Amerindian farming systems. Taken together with their previous work, these new findings suggest that gene flow between wild Manihot populations and cassava plants could potentially play a much greater role in the crop's evolution than previously thought.
由于无性繁殖作物很少进行有性繁殖，因此预计其与野生近缘种之间的基因流动机会远低于种子繁殖作物。迪普蒂埃及其同事的一项研究现已证明了一种无性繁殖作物与其近缘野生同属物种之间存在有性繁殖的证据。这些研究人员在法属圭亚那开展工作，记录了木薯（大戟科，Manihot esculenta ssp. esculenta）与附近生长的野生木薯种群之间通过渐渗杂交形成的一个杂交带，木薯是通过茎插进行繁殖的。杂合性模式表明，作物与这些野生种群之间的繁殖几乎没有障碍。这些研究人员之前的工作记录了在传统美洲印第安农业系统中，偶尔进行有性繁殖对木薯品种培育的重要性。结合他们之前的工作，这些新发现表明，野生木薯种群与木薯植株之间的基因流动在该作物的进化过程中可能发挥比之前认为的更大的作用。
