Yousefi A R, Jamshidi K, Oveisi M, Karimojeni H, Pouryosef M
Department of Agronomy and Plant Breeding, College of Agriculture, University of Zanjan, Iran.
Department of Agronomy and Plant Breeding, University of Tehran, Iran.
Plant Dis. 2013 May;97(5):694. doi: 10.1094/PDIS-08-12-0750-PDN.
Achillea wilhelmsii C. Koch (Asteraceae) is a wild herb widely disturbed in Iran and known locally as yarrow. This plant is an important medicinal plant and it has been used for its analgesic, antiphlogistic, antispasmodic, and antibacterial effects in Iranian folk medicine. Field surveys revealed infestations of yarrow broomrape, Orobanche purpurea Jacq., on A. wilhelmsii plants in two locations in province of Zanjan (Zanjan, 36°37'19.85″ N, 48°27'16.87″ E, 1,707.4 m elevation, and Qolabar, 36°19'19.85″ N, 48°19'16.41″ E, 1,663.9 m elevation) in northwestern Iran in May 2012. The annual mean air temperature and the average maximum and minimum air temperatures were 11, 18, and 4°C, respectively. The annual mean precipitation was 298 mm. The infestation of A. wilhelmsii was confirmed by verifying the attachment of the yarrow broomrape to the A. wilhelmsii roots. Broomrape plant heights were between 24 and 37 cm. The stems were erect, unbranched, slender, and swollen near the base at contact with host, 0.5 to 10 mm diameter. The leaves were reduced to scale or bracts up to 10 to 15 mm long. The flowers were in dense terminal spikes, usually restricted to the top third or half of the shoot. There was one bract and two bracteoles surrounding each flower. The bracts measured 7 to 10 mm, had ovate lanceolates shorter than the calyces, and lanceolate bracteoles were 5 to 10 mm. The calyces were gamosepalous, entire, and whitish. Corollas were 13 to 18 mm long, and were dull bluish-purple with dark veins, suffused with whitish-yellow at the base. The upper part was slightly curved forwards. Stamens were epipetalous, inserted 4 to 7 mm above the corolla base, with filaments glabrous. The anthers were glabrous along sutures. Stigma lobes were white. Fruit was an oval capsule, 0.9 to 10 mm. Botanists at the College of Agriculture of Zanjan University confirmed the identity of O. purpurea. A. millefolium has been reported as a host plant for yarrow broomrape (1,2). However, to our knowledge, this is the first report of yarrow broomrape on A. wilhelmsii in Iran. Since production and farming of A. wilhelmsii as a medicinal plant has recently started on a commercial scale in Iran, the parasite weed could pose a serious threat to production of this plant. References: (1) B. Prajs. Biodiv. Res. Conserve. 17:33, 2010. (2) J. Rumsey and S. L. Jury. Watsonia. 18:257, 1991.
南欧蓍草（菊科）是一种在伊朗广泛分布的野生草本植物，当地称为欧蓍草。这种植物是一种重要的药用植物，在伊朗民间医学中因其止痛、消炎、解痉和抗菌作用而被使用。实地调查发现，2012年5月在伊朗西北部赞詹省的两个地点（赞詹，北纬36°37'19.85″，东经48°27'16.87″，海拔1,707.4米；以及乔拉巴尔，北纬36°19'19.85″，东经48°19'16.41″，海拔1,663.9米），欧蓍草上寄生有紫花列当。年平均气温以及平均最高和最低气温分别为11℃、18℃和4℃。年平均降水量为298毫米。通过确认紫花列当附着在南欧蓍草的根部，证实了南欧蓍草受到了侵染。列当植株高度在24至37厘米之间。茎直立，不分枝，细长，在与寄主接触处基部附近肿胀，直径0.5至10毫米。叶子退化为鳞片或苞片，长达10至15毫米。花密集呈顶生穗状，通常局限于茎的上三分之一或一半。每朵花周围有一片苞片和两片小苞片。苞片长7至10毫米，卵形披针形，比花萼短，披针形小苞片长5至10毫米。花萼合生，全缘，白色。花冠长13至18毫米，暗淡的蓝紫色，有深色脉纹，基部略带淡黄白色。上部略向前弯曲。雄蕊着生于花冠上，在花冠基部上方4至7毫米处插入，花丝无毛。花药沿缝线无毛。柱头裂片白色。果实为椭圆形蒴果，长0.9至10毫米。赞詹大学农学院的植物学家确认了紫花列当的身份。曾有报道称西洋蓍草是紫花列当的寄主植物（参考文献1,2）。然而，据我们所知，这是伊朗首次报道紫花列当寄生在南欧蓍草上。由于伊朗最近已开始商业化种植南欧蓍草作为药用植物，这种寄生杂草可能对该植物的生产构成严重威胁。参考文献：(1) B. Prajs. Biodiv. Res. Conserve. 17:33, 2010. (2) J. Rumsey and S. L. Jury. Watsonia. 18:257, 1991.
