Herrero M L, Blanco R, Santos M, Tello J C
The Norwegian Crop Research Institute, Plant Protection Centre, N-1432, Ås, Norway.
Universidad de Almeria, Plant Production Department, 04120 Almeria, Spain.
Plant Dis. 2002 May;86(5):558. doi: 10.1094/PDIS.2002.86.5.558A.
In autumn 1999, crown and root rot along with wilting of cucumber (Cucumis sativus L.) were observed in greenhouses in southeastern Spain (Granada). Symptoms appeared again during the 2000 to 2001 growing season. In spring 2001, root and crown symptoms were observed also on melon (Cucumis melo L.) in greenhouses in another area of southeastern Spain (Almeria). Isolates from diseased plants from both locations were identified as Phytophthora capsici (Leonian). Isolates produced papillate sporangia of variable shape, some of them with two or three papilla. Sporangia were caducous with pedicels of variable lengths that could be longer than the sporangia. Three isolates were crossed with P. capsici strains of known mating type. All isolates produced amphigynous antheridia and were mating type A1. Isolates grew well at 35°C and did not produce chlamydospores. Pathogenicity was examined for one isolate from cucumber and one from melon. Cucumber and melon plants at the four-leaf stage and pumpkin (Cucurbita maxima × C. moschata) plants at the five-leaf stage were inoculated with a mycelium suspension. Both isolates caused wilting and death of plants on the three host species tested. The pathogen was reisolated from roots and stems of diseased plants. To our knowledge, this is the first time P. capsici has been found on cucumber in Spain. It is also the first time P. capsici has been found on melon in the greenhouses of southeastern Spain, and the first time it has been reported to cause root and crown rot of melon. Previously, P. capsici has been reported to cause disease of field-grown melon (2) and greenhouse-grown pepper (Capsicum annum) (1) in eastern and southeastern Spain, respectively. References: (1) J. C Tello. Comun. INIA 22, 1984. (2) J. J. Tuset Barrachina. An. INIA 7:11, 1977.
1999年秋季，在西班牙东南部（格拉纳达）的温室中，观察到黄瓜（Cucumis sativus L.）出现冠腐和根腐以及萎蔫症状。在2000至2001年生长季，这些症状再次出现。2001年春季，在西班牙东南部另一地区（阿尔梅里亚）的温室甜瓜（Cucumis melo L.）上也观察到根和冠部症状。从这两个地点患病植株上分离出的菌株被鉴定为辣椒疫霉（Phytophthora capsici (Leonian)）。分离菌株产生形状各异的具乳突孢子囊，其中一些有两个或三个乳突。孢子囊具脱落性，柄长短不一，可能长于孢子囊。将三个分离菌株与已知交配型的辣椒疫霉菌株进行杂交。所有分离菌株均产生两性雄器，交配型为A1。分离菌株在35°C下生长良好，不产生厚垣孢子。对一株来自黄瓜的分离菌株和一株来自甜瓜的分离菌株进行了致病性检测。用菌丝体悬浮液接种四叶期的黄瓜和甜瓜植株以及五叶期的南瓜（Cucurbita maxima × C. moschata）植株。这两个分离菌株均导致所测试的三种寄主植物萎蔫和死亡。从患病植株的根和茎中再次分离到该病原菌。据我们所知，这是西班牙首次在黄瓜上发现辣椒疫霉。这也是西班牙东南部温室中首次在甜瓜上发现辣椒疫霉，并且首次报道其可引起甜瓜根腐和冠腐。此前，分别在西班牙东部和东南部报道过辣椒疫霉可引起露地甜瓜（2）和温室辣椒（Capsicum annum）（1）发病。参考文献：（1）J. C Tello. Comun. INIA 22, 1984.（2）J. J. Tuset Barrachina. An. INIA 7:11, 1977.
