Brenneman T B, Padgett G B, McDaniel R G
Department of Plant Pathology, University of Georgia, Tifton 31793.
Louisiana Cooperative Extension Service, 212 Macon Rd., Winnsboro 71295.
Plant Dis. 1998 Sep;82(9):1064. doi: 10.1094/PDIS.1998.82.9.1064C.
Partridgepea (Cassia fasciculata Michx.) is grown in the southeastern U.S. in food plots for game birds. In 1997, numerous dead plants were observed in a commercial planting for seed production. Perithecia of Calonectria ilicicola Boedijin & Reitsma (imperfect stage: Cylindrocladium parasiticum Crous, Wingfield & Alfenas), a serious pathogen of peanut (Arachis hypogaea L.), were found on the crown of diseased plants. Two isolates each from partridgepea and peanut were grown on potato dextrose agar for 5 weeks. Microsclerotia produced were added to a 2:1 mixture of pasteurized field soil and Pro-mix potting medium (25 microsclerotia per g of mix). Both infested and noninfested potting mixes were put in Super Cell Cone-Tainers (Stuewe & Sons, Corvallis, OR) in the greenhouse and planted to one pre-germinated seed each of either peanut or partridgepea (10 replications). Soil moisture was kept at field capacity and after 7 weeks root rot severity (0 to 4 scale with 4 = dead plant) and fresh weight of whole plants and roots were determined. Mean disease ratings for peanut were 2.1 and 2.5 with the peanut and partridgepea isolates, respectively, and 0.1 for the controls. Mean disease ratings for partridgepea were 3.2 and 3.2 with the peanut and partridgepea isolates, respectively, and 1.0 for the controls. Peanut and partridgepea plant weights were reduced by 50 and 68%, respectively, compared with controls. Reductions in root weights were similar to those for whole plants. The pathogen was consistently recovered from diseased roots. In summary, all four isolates were pathogenic to both hosts, but partridgepea was more susceptible (P ≤ 0.05) than peanut to C. parasiticum. Sicklepod (Senna obtusifolia (L.) H. Irwin & Barneby), one of the most troublesome weeds in the southeastern U.S., was previously observed to have black rot symptoms and perithecia of C. ilicicola on the crowns of diseased plants. Plants grown in soil infested with an isolate of the fungus from sicklepod exhibited typical symptoms and the pathogen was reisolated from diseased tissue. Rotation with soybean (Glycine max L.) traditionally has been the major concern for peanut production in fields with a history of Cylindrocladium black rot; however, these additional hosts also should be considered.
鹧鸪豆（Cassia fasciculata Michx.）生长在美国东南部用于猎鸟的食物种植区。1997年，在一个用于种子生产的商业种植园中观察到大量植株死亡。在患病植株的冠部发现了花生（Arachis hypogaea L.）的一种严重病原菌——冬青拟茎点霉（Calonectria ilicicola Boedijin & Reitsma，无性阶段：寄生柱盘孢Cylindrocladium parasiticum Crous、Wingfield & Alfenas）的子囊壳。从鹧鸪豆和花生中各分离出两个菌株，在马铃薯葡萄糖琼脂培养基上培养5周。将产生的微菌核添加到经巴氏消毒的田间土壤和Pro-mix盆栽基质的2:1混合物中（每克混合物含25个微菌核）。将受侵染和未受侵染的盆栽混合物置于温室中的Super Cell Cone-Tainers（Stuewe & Sons，科瓦利斯，俄勒冈州）中，每种分别种植一粒预先发芽的花生或鹧鸪豆种子（10次重复）。土壤湿度保持在田间持水量，7周后测定根腐病严重程度（0至4级，4级表示植株死亡）以及全株和根系的鲜重。花生接种花生和鹧鸪豆分离株后的平均病情评级分别为2.1和2.5，对照为0.1。鹧鸪豆接种花生和鹧鸪豆分离株后的平均病情评级均为3.2，对照为1.0。与对照相比，花生和鹧鸪豆植株重量分别减少了50%和68%。根系重量的减少与全株相似。病原菌始终能从患病根系中重新分离出来。总之，所有四个分离株对两种寄主都有致病性，但鹧鸪豆比花生对寄生柱盘孢更敏感（P≤0.05）。镰荚决明（Senna obtusifolia (L.) H. Irwin & Barneby）是美国东南部最麻烦的杂草之一，此前观察到其患病植株的冠部有黑腐病症状和冬青拟茎点霉的子囊壳。在被来自镰荚决明的真菌分离株侵染的土壤中生长的植株表现出典型症状，并且病原菌能从患病组织中重新分离出来。在有柱盘孢属黑腐病病史的田块中，传统上与大豆（Glycine max L.）轮作一直是花生生产的主要关注点；然而，这些额外的寄主也应予以考虑。
