Trapero-Casas A, Kaiser W J
Departamento de Agronomía, ETSIAM, Universidad de Córdoba, Apdo. 3048, 14080 Córdoba, Spain.
Plant Dis. 1998 Sep;82(9):1063. doi: 10.1094/PDIS.1998.82.9.1063D.
Turnsole (Chrozophora tinctoria) is a common spring-summer weed in chickpea (Cicer arietinum) and other dry-land crop production areas in southern Spain. Under field conditions, this weed often develops a general wilt and eventual death associated with a vascular discoloration of stems and roots. Diseased turnsole plants frequently occurred together with chickpea plants affected by Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris, a major disease of chickpea crops in southern Spain (1). Isolations from roots, stems and leaf petioles of turnsole plants consistently yielded F. oxysporum, and it was morphologically similar to F. oxysporum f. sp. ciceris. To test the pathogenicity of this fungus, germinated and previously surface-sterilized seeds of turnsole and chickpea cultivar Blanco Lechoso were planted in a greenhouse soil mixture artificially infested with four isolates of F. oxysporum from turnsole and two isolates of F. oxysporum f. sp. ciceris, one of them inducing the wilt syndrome and the other causing yellowing (1). Pathogenicity tests were conducted following the standard inoculation method used for F. oxysporum in chickpea (1). Inoculated and control plants were maintained in a greenhouse at 15 to 30°C. Isolates of F. oxysporum from turnsole caused wilt symptoms and death of turnsole plants within 2 months, but chickpea isolates did not affect turnsole. Conversely, chickpea plants were affected only by the two isolates of F. oxysporum f. sp. ciceris from chickpea. All diseased chickpea and turnsole plants exhibited typical vascular discoloration. F. oxysporum was consistently reisolated from the vascular tissues of roots, stems, and leaf petioles of affected plants. Based on these results, the fungus causing wilt of turnsole was identified as a forma specialis of F. oxysporum different from the chickpea wilt pathogen. Since the Fusarium wilt diseases of turnsole and chickpea are caused by different pathogens, the occurrence of F. oxysporum causing wilt of turnsole in the field can not be used to forecast Fusarium wilt of chickpea, but it may be considered as a potential biocontrol agent of this weed under field conditions. This is the first report of F. oxysporum causing wilt of turnsole. Reference: (1) A. Trapero-Casas and R. M. Jiménez-Díaz. Phytopathology 75:1146, 1985.
黑面神（Chrozophora tinctoria）是西班牙南部鹰嘴豆（Cicer arietinum）及其他旱地作物产区常见的春夏杂草。在田间条件下，这种杂草常出现普遍萎蔫并最终死亡，同时茎和根的维管束变色。患病的黑面神植株常与受尖孢镰刀菌（Fusarium oxysporum f. sp. ciceris）引起的鹰嘴豆枯萎病影响的鹰嘴豆植株一同出现，尖孢镰刀菌是西班牙南部鹰嘴豆作物的一种主要病害（1）。从黑面神植株的根、茎和叶柄中持续分离出尖孢镰刀菌，其形态与尖孢镰刀菌鹰嘴豆专化型相似。为测试该真菌的致病性，将已发芽且先前进行过表面消毒的黑面神种子和鹰嘴豆品种布兰科·莱乔索（Blanco Lechoso）种子种植在人工接种了来自黑面神的4株尖孢镰刀菌分离株和2株尖孢镰刀菌鹰嘴豆专化型分离株的温室土壤混合物中，其中一株诱导萎蔫症状，另一株导致黄化（1）。致病性测试按照鹰嘴豆中尖孢镰刀菌的标准接种方法进行（1）。接种和对照植株置于15至30°C的温室中。来自黑面神的尖孢镰刀菌分离株在2个月内导致黑面神植株出现萎蔫症状并死亡，但鹰嘴豆分离株对黑面神没有影响。相反，鹰嘴豆植株仅受来自鹰嘴豆的2株尖孢镰刀菌鹰嘴豆专化型分离株的影响。所有患病的鹰嘴豆和黑面神植株均表现出典型的维管束变色。从受影响植株的根、茎和叶柄的维管束组织中持续重新分离出尖孢镰刀菌。基于这些结果，导致黑面神枯萎的真菌被鉴定为不同于鹰嘴豆枯萎病原菌的尖孢镰刀菌的一个专化型。由于黑面神和鹰嘴豆的镰刀菌枯萎病由不同病原菌引起，田间出现的导致黑面神枯萎的尖孢镰刀菌不能用于预测鹰嘴豆的镰刀菌枯萎病，但在田间条件下它可能被视为这种杂草的一种潜在生物防治剂。这是尖孢镰刀菌导致黑面神枯萎的首次报道。参考文献：（1）A. Trapero-Casas和R. M. Jiménez-Díaz。植物病理学75:1146，1985。
