The structure and function of "weediness supergene" responsible for the crop-weed complex of pearl millet

珍珠粟（Pennisetumglaucum）是非洲和印度半干旱地区的重要粮食作物。西非的珍珠粟田经常被杂草丛生的珍珠粟严重侵扰，这些珍珠粟有破碎的耳朵。我们之前已经证明，作物型珍珠粟和杂草型珍珠粟之间的差异是由单个基因座遗传决定的。这个基因被命名为杂草性，被认为是一个由多个连锁基因组成的“超基因”。本研究的主要目的是克隆和解析该超基因，目前取得的主要成果是：1）克隆了3个RAPD标记，测序并转化为切割扩增多态性序列（CAPS）标记。700个人。4）构建了杂草型珍珠粟的5x BAC文库，并对其中7个具有非典型表型的个体进行了多标记分析，结果表明：1）利用该文库构建了一个5x BAC文库，并选出两个具有连锁标记的BAC克隆。微卫星分析表明，在西非的珍珠粟田中，珍珠粟的异交率在正常作物类型中为95%，在杂草类型中为85%。

Pearl millet (Pennisetum glaucum) is a very important food crop in the semi-arid zones of Africa and India. Pearl millet fields of West Africa are often heavily infested with weedy pearl millet having shattering ears. We previously demonstrated that the difference between crop- and weed-type pearl millet is genetically determined by a single locus. This gene, named weediness, has been supposed to be a "supergene" consisting of linked multiple genes. Unfortunately, the primary objective of this research project, the cloning and decipherring of this supergene, has not yet been achieved.The achievements made so far are :1) Three linked marker bands derived from RAPD-based bulked segregant analysis were cloned, sequenced, and transformed into cleaved amplified polymorphic sequence (CAPS) markers.2) AFLP analysis was performed on a segregating familiy of c. 700 individuals. A total of eleven bands that were shown to be linked to the supergene were cut out, cloned and sequenced.3) Seven individuals with atypical phenotypes were proved to be recombinants based on multiple marker types.4) A 5x BAC library was constructed from the weed type pearl millet, and two BAC clones having the linked markers were selected out.5) A microsatellite analysis demonstrated that the outcrossing rate of pearl millet in a pearl millet field in West Africa was 95% in the normal crop type and 85% in the weed type.