Farrokhi-Nejad Reza, Cromey Matthew G, Moosawi-Jorf S Ali
Department of Plant Protection, Shahid Chamran University, Ahwaz, Iran.
Pak J Biol Sci. 2007 Nov 1;10(21):3786-93. doi: 10.3923/pjbs.2007.3786.3793.
A total of 58 isolates of Rhizoctonia spp. (46 R. solani and 12 binucleate Rhizoctonia) were recovered from potato tubers showing black scurf disease symptom during the 2004 growing season in Lincoln, New Zealand. The isolates were assigned to 5 Anastomosis Groups (AG) ofR. solani AG-3 (54.34%), AG-5 (28.26%), AG-8 (8.69%), AG-4 (6.52%) and AG-2-2 IIIB (2.17%) and six anastomosis groups ofbinucleate Rhizoctonia, AG-K (25%), AG-Bi (25%), AG-Ba (8.33%), AG-C (8.33%), AG-D (8.33%) and AG-E (8.33%). Two isolates of BNR did not anastomose with any of the tester strains and remain unidentified. In pathogenicity tests that were carried out on radish, carrot, lettuce, onion, tomato and hemp, it was found that all the isolates of both R. solani and binucleate Rhizoctonia to be virulent at varying degrees to these 6 plants species from different families. In these tests, isolates of AG-3 and AG-8 from R. solani population caused the highest and lowest disease severity on all 6 plant species, respectively. In population of binucleate Rhizoctonia, on the other hand, the highest and lowest disease severities were caused by the isolates of AG-D and AG-Ba on all test plants, respectively. When the results of the pathogenicity tests were examined in terms of the susceptibility levels of the plants, the most resistant plant was tomato against different AGs of R. solani and BNR. On the other hand, radish was the most susceptible plant species tested in this study against both R. solani and BNR isolates.
2004年生长季期间，在新西兰林肯地区，从表现出黑痣病症状的马铃薯块茎中总共分离出58株丝核菌属菌株（46株茄丝核菌和12株双核丝核菌）。这些分离菌株被归入茄丝核菌的5个融合群（AG），即AG-3（54.34%）、AG-5（28.26%）、AG-8（8.69%）、AG-4（6.52%）和AG-2-2 IIIB（2.17%），以及双核丝核菌的6个融合群，即AG-K（25%）、AG-Bi（25%）、AG-Ba（8.33%）、AG-C（8.33%）、AG-D（8.33%）和AG-E（8.33%）。有2株双核丝核菌分离株不与任何测试菌株融合，仍未鉴定出来。在对萝卜、胡萝卜、生菜、洋葱、番茄和大麻进行的致病性测试中，发现茄丝核菌和双核丝核菌的所有分离株对这6种来自不同科的植物都有不同程度的致病性。在这些测试中，茄丝核菌群体中的AG-3和AG-8分离株分别在所有6种植物上导致了最高和最低的病害严重程度。另一方面，在双核丝核菌群体中，AG-D和AG-Ba分离株分别在所有测试植物上导致了最高和最低的病害严重程度。当根据植物的易感性水平检查致病性测试结果时，最具抗性的植物是番茄，它对茄丝核菌和双核丝核菌的不同AG都有抗性。另一方面，萝卜是本研究中对茄丝核菌和双核丝核菌分离株最敏感的测试植物物种。
