Rhododendron, large vascular plant genera with tens of thousands of cultivars, possesses valuable horticultural, medicinal, and ecological properties. However, the genetic studies have been hindered due to lack of effective genetic markers. In this study, microsatellite markers have been developed in R. obtusum Hort. ex Wats. variety 'Yanzhimi' based on RNA-seq. Di-nucleotide repeats (23,849, 63.131%) were the main type, followed by mono-nucleotide (8.544, 22.6169%) and tri-nucleotide motifs (4,078, 10.7949%). In particular, A/T (8,237, 21.804%), AG/CT (20,546, 54.388%), AAG/CTT (1,182, 3.129%), AAAG/CTTT (50, 0.132%) were dominant for mono-, di-, tri-, tetra-nucleotide repeat types, respectively. Totally, 30 EST-SSR markers gave out 196 polymorphic bands with an average of 6.53 bands per locus. N_A and N_E ranged from 3 to 17 and 1.28 to 6.75, with average values of 6.53 and 2.98, respectively. Rhododendron cultivars possessed relatively high genetic diversity at species level (with the average PIC value of 0.647), and frequent gene flow occurred with the mean value of 3.89. These 94 accessions could be clustered into 4 pops, and cultivars of the same origin and those bred by related parents tended to be clustered together. The clustering and fingerprint profiles effectively supported the authentication of tested cultivars. These EST-SSR markers could be used for further cultivar identification, marker-assisted selection, as well as identification of gene-trait relationship in Rhododendron species.

杜鹃花是一种大型维管植物属，有数万个品种，具有宝贵的园艺、药用和生态特性。然而，由于缺乏有效的遗传标记，遗传研究一直受到阻碍。在这项研究中，已经在R. obtusum Hort 中开发了微卫星标记。前瓦茨。基于RNA-seq的品种'Yanzhimi'。二核苷酸重复 (23,849, 63.131%) 是主要类型，其次是单核苷酸 (8.544, 22.6169%) 和三核苷酸基序 (4,078, 10.7949%)。其中A/T（8,237, 21.804%）、AG/CT（20,546, 54.388%）、AAG/CTT（1,182, 3.129%）、AAAG/CTTT（50, 0.132%）对单、双- ，三，四核苷酸重复类型，分别。30 个EST-SSR 标记共产生196 个多态性条带，平均每个基因座有6.53 个条带。N _A和N _{E 的}范围为 3 至 17 和 1.28 至 6.75，平均值分别为 6.53 和 2.98。杜鹃花品种在物种水平上具有较高的遗传多样性（平均PIC值为0.647），基因流动频繁，均值为3.89。这94个种质可以聚集成4个流行，同源品种和由相关亲本培育的品种往往聚集在一起。聚类和指纹图谱有效地支持了测试品种的认证。这些EST-SSR标记可用于杜鹃花品种的进一步品种鉴定、标记辅助选择以及基因-性状关系的鉴定。