Division of Applied Bioscience and Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea.
Int J Food Microbiol. 2010 Apr 15;138(3):238-42. doi: 10.1016/j.ijfoodmicro.2010.01.019. Epub 2010 Jan 25.
Embellisia allii results in the formation of a bulb canker and black soot on the surface of different alliums and it has been frequently detected on garlic bulbs together with the spoilage fungus, Fusarium oxysporum f. sp. cepae, which causes bulb basal plate rot. In this study, the influence of water activity (a(w)) and temperature on mycelial growth of E. allii and F. oxysporum f. sp. cepae, conidial size and sporulation of E. allii, interactions between E. allii and F. oxysporum f. sp. cepae, Index of Dominance (I(D)), and in situ virulence on garlic were examined. Mycelial growth of E. allii was optimal (5.97 mm/day) at 0.995 a(w) and 25 degrees C, slower at 30 degrees C. However, almost no growth occurred at 0.937 a(w)/30 degrees C. F. oxysporum f. sp. cepae grew faster than E. allii, (6.3-7.4mm/day) at 30 degrees C. Interactions between E. allii and F. oxysporum f. sp. cepae were influenced by a(w) and temperature. Sporulation of E. allii was more abundant on PDA than on MEA, especially at high a(w) (0.995) and low temperature (20 degrees C), but almost no sporulation occurred at 30 degrees C regardless of nutritional medium or a(w) level. The spore length of E. allii was longer on PDA than MEA, and was significantly influenced by water availability. F. oxysporum f. sp. cepae was competitive against E. allii and had a higher I(D) value in comparison with E. allii especially at a higher temperature (30 degrees C). In situ virulence tests showed that E. allii was weakly virulent on the garlic bulb cloves while that of F. oxysporum f. sp. cepae was highly dependent on a(w).
大蒜蒜盘盘枯病菌导致不同大蒜属植物的鳞茎出现溃疡和表面黑色煤烟状，并常与腐霉菌，尖孢镰刀菌引起的大蒜鳞茎基部腐烂一同出现。本研究旨在探讨水分活度（a(w)）和温度对大蒜蒜盘盘枯病菌和尖孢镰刀菌的菌丝生长、大蒜蒜盘盘枯病菌分生孢子大小和产孢、二者互作、优势度指数（I(D)）和原位致病力的影响。大蒜蒜盘盘枯病菌在 0.995 a(w)和 25°C时生长最佳（5.97mm/天），在 30°C时较慢。然而，在 0.937 a(w)/30°C时几乎不生长。尖孢镰刀菌在 30°C时比大蒜蒜盘盘枯病菌生长更快（6.3-7.4mm/天）。大蒜蒜盘盘枯病菌和尖孢镰刀菌的互作受 a(w)和温度的影响。大蒜蒜盘盘枯病菌在 PDA 上的产孢量多于 MEA，尤其是在高 a(w)（0.995）和低温（20°C）下，但无论营养培养基或 a(w)水平如何，在 30°C时几乎不产孢。大蒜蒜盘盘枯病菌在 PDA 上的孢子长度长于 MEA，且受水分供应的显著影响。与大蒜蒜盘盘枯病菌相比，尖孢镰刀菌对其具有更强的竞争力，且在较高温度（30°C）下具有更高的 I(D)值。原位致病力测试表明，大蒜蒜盘盘枯病菌对大蒜鳞茎的致病力较弱，而尖孢镰刀菌对其的致病力高度依赖于 a(w)。
