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Sclerotium rolfsii
- 1. Instructor- Dr. R.P SinghDr. R.P Singh Dr. Shilpi RauwatDr. Shilpi Rauwat G.B.P.U.A.& T, Pantnagar Presented by - Prince Kumar GuptaPrince Kumar Gupta Ph.D (Ag.) student G.B.P.U.A.& T, Pantnagar
- 6. Geographical distributionâŚ. United state of America S. Africa Australlia India Brazil Russia Robert,P.D (2003)
- 7. S.Rolfsii introductionâŚâŚ.. ďą The pathogen associated with collar rot, root rot, stem rot, crown rot or whole plant blight, wilting and damping off ďą Sclerotium rolfsii is the anamorphic stage, Telomorph stage rarely observed. Classification Kingdom Fungi Phylum Basidiomycota Class Agaricomycetes Order Atheliales Family Atheliaceae Genus Athelia Host range of S.rolfsii is so broad, at least 500 sp in 100 families are susceptible. Legumes, crucifers and cucurbits were considered as the most common hosts.
- 9. Microscopic view of S. rolfsii
- 10. Morphological studies⌠asexual stage(anamorph)
- 11. Morphological studies⌠Asexual Stage (anamorph)
- 13. Morphological studies⌠Sexual stage(Teleomorph)Sexual stage(Teleomorph) BasiodosporeBasiodospore SterigmataSterigmata BasidiumBasidium
- 15. Sexual Stage (teleomorph) ⢠In 1926, the sexual stage of basidiomycetous fungus was first described in Japan. The currently accepted name for teleomorph Athelia rolfsii. â˘Sexual stage not commonly seen. As in other Basidiomycetes, A. rolfsii produces structure called a basidium in which meiosis occurs. ⢠Four haploid basidiospores are produced at the tips of small structures on the basidium called sterigmata ⢠Athelia rolfsii produces basidia in an unprotected layer (hymenium), which develops under humid conditions at lesions margins. The hymenium appears as white, yellow, or buff-colored granular with slightly wavy surface. ⢠The basidia are obovoid (oval shaped with one end being narrower than the other), 7-9 microns long and 4-5 microns wide. When mature, the basidiospores are forcibly discharged
- 16. Disease cycle of S.rolfsii
- 17. Hosts, Signs, and Symptoms ď S. rolfsii causes disease on numbers of plant species viz; field, vegetable, fruit etc. Disease caused by S. rolfsii destructive to numerous vegetable and fruit crops, especially tomato, pepper, melon, and watermelon ď Infection signs includes development of white strands mycelium in a fan- shaped pattern on lower stems, leaf litter, and soil.  ď Even under dry conditions, at least a trace of white mycelium should be evident on the surface of the stem or crown. In some cases, mycelium will be found only underground. After 7 to 14 days, tan-to-brown, mustard- seed-sized (0.5 to 1.5 mm) sclerotia form on the mycelial matÂ
- 18. ď Although symptoms vary with the host affected, infection usually restricted to plant parts in contact with the soil. Early symptoms consist of water- soaked lesions on crown and lower stem tissue. The disease usually recognized by yellowing and wilting of foliage, followed by complete collapse of the plant. ď On tomato and pepper, dark water-soaked lesions on the lower stem at or near the soil surface are present and rapidly develop to completely girdle the stem Infection of cucumber and watermelon is normally restricted to fruit lying in contact with the soil.    Fruits rot
- 19. ⢠Lower stem decay develops, plants usually remain erect and foliage wilts. On many host plants, wilted leaves gradually become brown and remain hanging on the plant (Pattmark et al., 1996) â˘Sclerotia serve as overwintering bodies and may be seen in the mycelium, on diseased tissues above or below ground or on soil surfaces. ⢠Lower stem decay develops, plants usually remain erect and foliage wilts. On many host plants, wilted leaves gradually become brown and remain hanging on the plant (Pattmark et al., 1996) â˘Sclerotia serve as overwintering bodies and may be seen in the mycelium, on diseased tissues above or below ground or on soil surfaces. Lower stem rot symptoms
- 20. ⢠On some plants, such as tomato, pepper, and sweet potato, root infection may follow crown infection (Bowen et al., 1992) ⢠On apples, roots are the primary infection site and crown rot develops subsequently. ⢠Usually the characteristic white mycelia mat and sclerotia develop near and on infected crown tissues or in and around roots close to the soil surface ⢠The leaves eventually die and branch die back develops. Root Decay symptoms
- 21. Survival
- 26. ď Select field that are free of S. rolfsii ď Deep plowing at depths below 20-30 cm, sclerotia do not survive longer than 45 days. ďWeed control must be maintained during rotations to prevent inoculum increase ďCrop rotations with non-host crop like corn or small grains prevent diseases. (Robert, P.D 2014) ď Staking plants prevent fruit from touching the ground. ď Avoided rotations with peanuts, soybeans, cabbage, and carrots. ď Black plastic mulch and row covers provides barrier between fruit and soil. ď Soil pH at 6.5 by addition of lime help to prevent fungal growth. CULTURALCULTURAL
- 28. ď Aeration of the soil and removal of thatch or other plant debris will also aid in suppressing S. rolfsii growth (Bowen et al., 2010). ď Close plant spacing and over-irrigation promote disease development avoided. ď Six tomato breeding linesâ5635M, 5707M, 5719M, 5737M, 5876M, and 5913Mâresistant to Sclerotium rolfsii were released jointly from Texas A&M University Research Center, Coastal Plain Experiment Station and the University of Georgia. ( Leeper , P.W) ď Grafting tomato plants onto interspecific hybrid rootstocks has also been successful in managing disease
- 30. ⢠In some large nurseries or greenhouses, it may be possible to treat beds or bulk soil with aerated steam. ⢠All areas must be brought to a temperature of 160- 180o F for 30 minutes. Treated soil should be stored away from contaminated areas. ⢠Even after steam treatment, some sclerotia may survive and losses may occur. Heat
- 32. ⢠Sclerotia grown in vitro are still viable after 12 hours at 450 C, but are killed in 4-6 hours at 50ºC and in 3 hours at 55ºC . ⢠Covering soil with transparent polyethylene sheets during the hot season increases soil temperatures and kills sclerotia. ⢠Field trials have achieved sclerotia degradation at 1 cm, but eradication at greater depths usually did not occur. This method requires immediate planting, which excludes crops that are planted in spring because temperatures are not high enough to affect sclerotia. ⢠Soil solarization combined with the addition of Trichoderma harzianum has been shown to decrease disease incidence more than either treatment alone. (Kator et al. 2015)
- 33. 33
- 34. ď Compost, oat, or straw added to the soil has been shown to limit disease incidence. The addition of an amendment may increase populations of antagonistic soil microorganisms. ď This effect may be due to the increase of toxic ammonia and/or the increase of certain soil microorganisms in the soil. ď An organic (sugar derivative) amendment, has been shown to change the soil microflora, and this change has been related to a decrease of S. rolfsii in the soil in lab and greenhouse studies. ď Neem oil and pine bark extracts or pine bark powders have resulted in reduced growth of S. rolfsii. Amendments:
- 35. Organic extracts Average dia. of pathogen (mm) after 5 days Growth inhibition (%) No. of sclerotia/plate after 10 days Mustard cake 8.77 11.83 302.33 Castor cake 8.66 14.12 271.67 Neem cake 7.68 32.44 186.00 FYM 8.01 26.34 200.0 Press mud 8.62 14.89 262.00 Poultry manure 8.70 13.36 280.33 Control 9.34 - 390.20 S.Em (Âą) 0.12 - 6.36 c.v 2.14 - 4.09 Mean of three replications P.D. Madhukarrao, 2013
- 36. Biological control ďź Along with species of Trichoderma, other biological agents, such as Gliocladium virens, Bacillus subtilis, and Penicillium spp., were found to antagonize S. rolfsii and help in disease suppression. ďź Gliocladium virens reduce number of sclerotia in soil to a depth of 30 cm ďź Trichoderma koningii reduced sclerotia number in tomato fields ďź Recently, isolate of Streptomyces philanthi found effective against S. rolfsii in chilli. (Boukaew et.al 20.11)
- 37. Biocontrol agents Average dia. of pathogen (mm) Growth inhibition (%) Trichoderma viride 5.97 35.93 Trichoderma harzianum 5.48 46.11 T. Koningii 6.30 28.74 Pseudomonas florescence 5.77 40.12 Bacillus subtallis 6.40 26.35 Control 7.46 S.Em (Âą) 0.07 c.v 1.83 Mean of three replications P.D. Madhukarrao, 2013
- 38. Chemical control Hexaconazole, tabuconazole can be used @ 1ml/ ltr Fosetyl Al @ 2gm/ltr Mancozeb @ 2 gm/ltr Copper oxy chloride @ 3gm/ltr Carbendazim @ 1gm/ltr Thiophanate methyl @ 1g/ltr (Rakholiya. 2015)
- 40. ConclusionâŚ.. S. Rolfsii described by Saccardo and pathogen having broad geographical distribution & having wide host range. Mycelium, white, hyaline hyphal having clamp connection. Four haploid basidiospores on basidium Sypmtoms, white strand mycelium, fan shaped pattern on plant parts Management practices, its protect the plant from various diseases. pH, acidic for mycelia and sclerotia germination 3.0-5.0 and 2.0-5.0 respectively. Temperature, mycelial growth 25-35°C
- 41. ď§ Roberts, P. D., French-Monar, R. D., and McCarter, S. M. 2014. Southern Blight. Pp. 43-44 in: Compendium of Tomato Diseases, 2nd edition, Jones, J. B., Zitter, T. A., Momol, M. T., and Miller, S. A. (eds.). APS Press. St. Paul, MN. ⢠Xie, C., and Vallad, G. 2010. Integrated Management of Southern Blight in Vegetable Production. Publication #PP272. Florida Cooperative Extension Service. ⢠Leeper, P. W., Phatak, S. C., and George, B. F. 1992. Southern blight-resistant tomato breeding lines: 5635M, 5707M, 5719M, 5737M, 5876M, and 5913M. Hortscience 7:475-478. ⢠Fery, R. L., and Dukes, P. D. Sr. 2005. Potential for utilization of pepper germplasm with a variable reaction to Sclerotium rolfsii Sacc. to develop southern blight-resistant pepper (Capsicum annuum L.) cultivars. Plant Genetic Resources 3:326-330. ⢠Rivard, C. L., OâConnell, S., Peet, M. M., and Louws, F. J. 2010. Grafting tomato with inter- specific rootstock to manage diseases caused by Sclerotium rolfsii and southern root-knot nematode. Plant Dis. 94:1015-1021. ⢠Bulluck, L. R., III, and Ristaino, J. B. 2002. Effect of synthetic and organic soil fertility amendments on southern blight, soil microbial communities, and yield of processing tomatoes. Phytopathology 92:181-189. ⢠Ristaino, J. B., K. B. Perry, and R. D. Lumsden. 1991. Effect of solarizaton and Gliocladium virens on sclerotia of Sclerotium rolfsii, soil microbiota, and the incidence of southern blight of tomato. Phytopathology 81:1117-1124. REFERENCES
- 42. ⢠Latunde-Data, A. O. 1993. Biological control of southern blight disease of tomato caused by Sclerotium rolfsii with simplified mycelial formulations of Trichoderma koningii. Plant Pathology 42:522-529. ⢠Boukaew, S., Chuenchit, S., Petcharat, V. 2011. Evaluation of Streptomyces spp. for biological control of Sclerotium root and stem rot and Ralstonia wilt of chili pepper. BioControl 56:365â 374. ⢠Roberts, P. D. 2003. Southern Blight. Pp. 20-21 in: Compendium of Pepper Diseases, Pernezny, K. L., Roberts, P. D., Murphy, J. F., and Goldberg, N. P. (eds.). APS Press. St. Paul, MN. ⢠Bruton, B. D. 1996. Southern Blight. Pp. 56 in: Compendium of Cucurbit Diseases, Zitter, T. A., Hopkins, D. L., and Thomas, C. E. (eds.). APS Press. St. Paul, MN. ⢠Punja, Z. K. 1985. The biology, ecology, and control of Sclerotium rolfsii. Annual Review of Phytopathology 23:97-127. Farr, D. F., and Rossman, A. Y. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved March 14, 2014, from http://nt.ars-grin.gov/fungaldatabases ⢠K. B. RAKHOLIYA. 2015. SCREENING OF FUNGICIDES AGAINST SCLEROTIUM ROLFSII CAUSING STEM ROT OF GROUNDNUT.Bio scan. 10(2): 691-694, 2015 ⢠P.D.Madhukarrao.2013.management of foot rot (sclertotium rolfsii (Sacc.) of finger millet.department of plamt pathology N.M college of gujrat. ⢠Rivard, C. L., OâConnell, S., Peet, M. M., and Louws, F. J. 2010. Grafting tomato with inter- specific rootstock to manage diseases caused by Sclerotium rolfsii and southern root-knot nema-tode. Plant Dis. 94:1015-1021.