兰科植物遗传图谱与QTL定位研究进展

兰科植物俗称兰花，是最重要的观赏花卉，构建遗传图谱，特别是高密度遗传图谱有助于提高育种水平，本研究主要对兰科植物遗传图谱与重要性状的QTL定位进行了综述。结果表明:1)2007年报道出兰科石斛属第一张遗传图谱以来，累计发表了13张兰科植物遗传连锁图谱。2)从图谱类型来看，5张为品种间图谱，8张为种间图谱；从图谱用途来分，7张可以用于QTL定位，3张可用于精细定位或基因克隆，另3张为基础参考图谱。3)从已构建的兰科植物遗传图谱看，总图距越来越高且平均图距越来越小，为图谱的实际应用奠定了基础，但作图群体较小始终是个问题。4)虽然在蝴蝶兰叶片、花色，石斛兰萼片大小及石斛茎及多糖含量等相关性状上进行了QTL定位，但在花朵大小、花朵数、花香、花型、花斑和植株抗性等方面均未涉及。因此，构建遗传图谱，特别是高密度遗传图谱能够为兰花的生物学研究及分子标记辅助育种提供参考依据。

Research progress of genetic maps and QTL mapping in Orchidaceae

Orchidaceae, commonly known as orchids, is the most important ornamental flowers. Constructing genetic maps, especially high-density genetic maps, can improve breeding level, this paper reviewed the genetic map and QTL mapping of important traits of Orchidaceae plants. The results showed that: 1)Since the first genetic map of Dendrobium in Orchidaceae was published in 2007, a total of 13 linkage maps of Orchidaceae plants have been published. 2)In terms of map type, 5 maps are for inter-cultivar mapping and 8 maps are for inter-species mapping. In terms of map usage, 7 maps could be used for QTL mapping and 3 maps could be used for fine mapping or gene cloning. 3)According to the constructed genetic map of Orchidaceae, the total map distance is higher and the average map distance is smaller which lays a foundation for the practical application of the map. However, the small mapping population is always a problem. 4)Although QTLs are mapped for leaf and flower color of Phalaenopsis, sepal size and stem and total polysaccharide contents of Dendrobium, but it is not involved in flower size, flower number, flower fragrance, flower type, flower spot, plant resistance and so on. Therefore, the construction of genetic map, especially the high-density genetic map can provide reference for the biological research and molecular marker-assisted breeding.