Razaghi P, Zafari D
Plant Protection Department, Faculty of Agriculture, University of Bu-Ali Sina, Hamedan, Iran.
J Appl Microbiol. 2017 May;122(5):1275-1285. doi: 10.1111/jam.13411. Epub 2017 Mar 22.
To identify a potential pathogenic isolate of fungus on Convolvulus arvensis and to determine its phytotoxic activity, which revealed the presence of toxic metabolites responsible for the toxicity against the target weed.
A high virulent isolate of the fungus, Phoma crystallifera was isolated from symptomatic field bindweed in the west of Iran and was screened for the production of phytotoxins, which promoted necrosis on the detached leaves and seedlings of field bindweed in the bioassays. The isolate was distinct from other isolates of the fungi on the basis of morphological characteristics and the combined sequence database of the ITS region, partial LSU rDNA and β-tubulin gene. Isolate P. crystalifera P6 produced the highest amount of phytotoxins after 21 days in a shacked culture of Richard's broth. The active metabolites were isolated from a cell-free culture filtrate by ethyl-acetate and purified by thin layer chromatography. The result indicated that six out of nine spots had phytotoxic activity in the bioassays, with R values of 0·16, 0·30, 0·36, 0·43, 0·57 and 0·81.
Phoma crystallifera P6 and its active metabolites showed significant phytotoxic effects on the detached leaves of C. arvensis.
To date, there are no reports of possible biocontrol agent(s) on C. arvensis in Iran. Thus, P. crystallifera P6 is introduced here as a severe pathogenic fungus and which can be used as a biocontrol agent against C. arvensis.
鉴定田旋花上一种潜在的致病真菌分离株，并确定其植物毒性活性，该活性揭示了对目标杂草具有毒性的有毒代谢产物的存在。
从伊朗西部有症状的田旋花中分离出一种高毒力的真菌分离株——结晶茎点霉，并对其进行植物毒素产生的筛选，在生物测定中，该毒素可促使田旋花离体叶片和幼苗坏死。基于形态特征以及ITS区域、部分LSU rDNA和β-微管蛋白基因的联合序列数据库，该分离株与其他真菌分离株不同。在Richard肉汤振荡培养21天后，结晶茎点霉分离株P6产生的植物毒素量最高。通过乙酸乙酯从无细胞培养滤液中分离出活性代谢产物，并通过薄层色谱法进行纯化。结果表明，九个斑点中有六个在生物测定中具有植物毒性活性，R值分别为0·16、0·30、0·36、0·43、0·57和0·81。
结晶茎点霉P6及其活性代谢产物对田旋花离体叶片表现出显著的植物毒性作用。
迄今为止，伊朗尚无关于田旋花可能的生物防治剂的报道。因此，在此将结晶茎点霉P6作为一种严重致病真菌引入，它可作为防治田旋花的生物防治剂。
