Pathogenicity of Rhizoctonia solani, the causal agent of crown and root rot of cucurbits in Iran

Subject Areas : دو فصلنامه تحقیقات بیماریهای گیاهی

S.M. Mirmajlessi ¹ (پژوهشگاه علوم و فنون هسته ای، پژوهشکده تحقیقات کشاورزی، پزشکی و صنعتی، کرج.)
Naser Safaie ² (گروه بیماری شناسی گیاهی، دانشکده کشاورزی، دانشگاه تربیت مدرس.)
H.A. Mostafavi ³ (پژوهشگاه علوم و فنون هسته ای، پژوهشکده تحقیقات کشاورزی، پزشکی و صنعتی، کرج.)
S.B. Mahmoudi ⁴ (موسسه تحقیقات چغندر قند کشور.)

Received: 2013-11-04 Accepted : 2013-11-04 Published : 2013-09-23

Keywords: Rhizoctonia solani, AG4, Crown and root rot, Cucurbits, Pathogenicity test,

Abstract :

The cucurbit damping off, root and crown rot caused by Rhizoctonia solani Kuhn are the most important diseases of these crops. In a survey of fields and greenhouses during 1384-1385 samples of cucumber, pumpkin, watermelon and melon, suspected of being infected by Rhizoctonia in Tehran, Mazandaran, Khouzestan and Isfahan provinces were collected and the fungus was isolated. In this study, 59 isolates of R. solani were recovered from soil, crown and roots of cucumber, pumpkin, watermelon and melon. Hyphae width ranged from 4.46 to 6.86 μm, and all of them were multinucleate. Anastomosis grouping showed that 81% of samples belonged to AG4 and the rest of isolates did not anastomose with either of the standards AG2 and AG7. The results of pathogenicity test showed that of the 59 recovered isolates, 97% were pathogenic, which in turn were classified in 10 separate categories based on their virulence. In this investigation two isolates of pumpkin and cucumber belonging to AG4 from Isfahan province appeared to be non pathogenic. This is considered to be the first report of AG4 on pumpkin in Iran.

References:

1. Ad Anderson N.A.1982. The genetics and pathology of Rhizoctonia solani. Annual Review of Phytopathology 20: 329-374.


2. Ashkan M., Abusaidi D. and Hamdollah-zadeh A. 1995. Pre and post emergence damping-off of pistachio caused by Rhizoctonia solani. Proc. 12^th Plant Protection Congress, Karaj, Iran.


3. Burpee L.L., Sanders P.L., Cole H.Jr. and Sherwood R.T.1980. Anastomosis groups among isolates of Ceratobasidium cornigerum and related fungi. Mycologia 72: 689-701.


4. Carling D.E. and Sumner D.R. 1992. Rhizoctonia spp. pp. 157-165, in: Methods for Research on Soilborn Phytopathogenic Fungi. By Singleton, L. L., Mihail, j. d., and Rush, C. M. (Editors).


5. Carling, D.E., Kuninaga S. and Brainard K.A.2002. Hyphal anastomosis reaction, DNA-internal transcribed spacer sequences, and virulence levels among subsets of Rhizoctonia solani anastomosis group-2 (AG-2) and AG-BI. Phytopathology 92: 43-50.


6. Cubeta M.A. and Vilgalys R. 1997. Population biology of the Rhizoctonia solani complex. Phtopathology 87: 480-484.


7. Hamdollah-zadeh A. and Rahimian H. 1989. Anastomosis group 4 is the major cause of Rhizoctonia solani of cotton and soybean in Gorgan. Proc. 9^th Plant Protection Congress, Mashhad, Iran.


8. Kroland W.C. and StanghelliniM.E.1988. Clean slide technique for the observation of anastomosis and nuclear condition of Rhizoctonia solani. Phytopathology 78: 820-822. 


9. Martin S.B. and Lucas L.T. 1984. Characterization and Pathogenicity of Rhizoctonia spp. And binucleate Rhizoctonia like fungi from turfgrasses in north Carolina. Phytopathology 74: 170-175.


10. Mathew K.A. and Gupta S.K. 1996. Studies on web blight of French bean caused by Rhizoctonia solani and its management. Indian Journal Mycological. Plant Pathology. 26: 171–177.


11. Ogoshi A. 1987. Ecology and pathogenicity of anastomosis and intraspecific groups of Rhizoctonia solani Kuhn. Annual Review of Phytopathology 25: 125-143.


12. Ogoshi A. 1996. The genus Rhizoctonia. pp. 1- 9. In: RhizoctoniaSpecies: Taxonomy, Molecular Biology,Ecology, Pathology and Disease Control. By Sneh, B., Jabaji-Hare, S., Neate, S., and Dijist, G.  (Editors).


13. Parmeter J.R.Jr., Sherwood R.T. and Platt W.D. 1969. Anastomosis grouping among isolates of Thanatephorus cucumeris. Phytopathology 59: 1270-1278.


14. Rahimian H. 1986. Rhizoctonia soil rot of tomato. Proc. 8^th Plant Protection Congress, Esfahan, Iran.


15. Safaei N., Minassian V., Rahimian H. and Banihashemi Z. 1996. Isolation identification and pathogenicity of Rhizoctonia fungi isolated from several. Host plants in the Khuzestan province. Iranian Journal of Plant Pathology 35: 1-8.


16. Sneh B., Burpee L. and Ogoshi A. 1991. Identification of Rhizoctonia Species. APS Press. 133p.


17. Vilgalys R. and Gonzalez D. 1990. Ribosomal DNA restriction fragment length polymorphisms in Rhizoctonia solani. Phytopathology 78: 698-702.


18. Windels S.C.E. and Nabben D.J. 1989. Characterization and pathogenicity of anastomosis groups of Rhizoctonia solani isolated from Beta vulgaris. Phytopathology 79: 83-88.


19. Zamani M.R., Balali Gh., Danesh D. and Rahimian H. 1989. Anastomosis groups of Rhizoctonia solani isolated from several hosts in Isfahan. Proc. 4^th Plant Protection Congress, Mashhad, Iran.