Broomrapes (Orobanche and Phelipanche species, Orobanchaceae) are obligate root parasites of dicotyledonous plants. This taxonomic group includes seven weedy parasites of agricultural crops that damage vegetables, sunflower (Helianthus annuus L.), and legumes. Processing-tomato (Solanum lycopersicum L.) fields in Israel have been recently found infested with a new broomrape, first identified as nodding broomrape (Orobanche cernua Loefl.) based on its host. However, its morphology resembled the closely related sunflower broomrape (Orobanche cumana Wallr.), an obligate parasite of sunflower. The new race (CUCE) parasitized sunflower, tomato, and tobacco (Nicotiana tabacum L.) in vitro, in a polyethylene bag system and in pots. Its seeds germinated in response to strigolactones (orobanchol, 5-deoxystrigol, 2′-epiorobanchol, and GR24) and dehydrocostus lactone (DCL), whereas O. cumana seeds responded only to DCL and GR24, and O. cernua only to strigolactones. Based on morphological similarities with O. cumana, shared molecular markers with O. cumana, ability to parasitize sunflower and respond to sunflower-germination stimulants, it was concluded that CUCE is a new race of O. cumana, with a host range expanding to Solanaceae crops. While being an important noxious weed of sunflower, this new O. cumana race is currently spreading and posing a threat to processing tomato in Israel. This finding is an alarming indication that broomrapes can shift host range and that similar new races of O. cumana could potentially appear in other countries.

中文翻译：

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由于种子对独脚金内酯反应的变化，一种新的向日葵（Orobanche cumana）品种具有更广泛的寄主范围

扫帚菜 (奥罗班什和菲利潘切种（Orobanchaceae）是双子叶植物的专性根寄生虫。这个分类群包括七种损害蔬菜的农作物杂草寄生虫，向日葵（向日葵L.) 和豆类。加工番茄（番茄L.) 最近在以色列的田野中发现了一种新的扫帚草，最初被确定为点头扫帚草（奥罗班切Loefl.) 基于其宿主。然而，它的形态类似于密切相关的向日葵扫帚（奥罗班奇库马纳Wallr.)，一种向日葵的专性寄生虫。新种族（CUCE）寄生向日葵、番茄和烟草（普通烟草L.) 体外、聚乙烯袋系统和盆中。它的种子响应独脚金内酯（orobanchol、5-deoxystrigol、2'-epiorobanchol 和 GR24）和 dehydrocostus lactone (DCL) 而发芽，而O. cumana种子只对 DCL 和 GR24 有反应，并且O. cernua只对独脚金内酯。基于形态相似性O. cumana, 与共享分子标记O. cumana，寄生向日葵和对向日葵发芽刺激物作出反应的能力，得出的结论是CUCE是一个新的种族O. cumana, 主机范围扩展到茄科庄稼。作为一种重要的向日葵有害杂草，这种新的O. cumana种族目前正在蔓延，并对以色列的番茄加工构成威胁。这一发现是一个令人震惊的迹象，表明扫帚可以改变宿主范围，并且类似的新种族O. cumana可能会出现在其他国家。