TY - JOUR T1 - Determination of the Effects of Hot Water Treatments on Spore Germination and Mycelial Growth of Fusarium fujikuroi, the Causal Agent of Rice Bakanae Disease TT - Çeltik Bakanae Hastalığı Etmeni Fusarium fujikuroi'nin Spor Çimlenmesi ve Misel Büyümesi Üzerine Sıcak Su Uygulamalarının Etkilerinin Belirlenmesi AU - Eğerci, Yeşim AU - Hekimhan, Hakan AU - Cer, Ceren PY - 2026 DA - May Y2 - 2026 DO - 10.66598/ijafls.1866708 JF - International Journal of Agriculture Forestry and Life Sciences JO - Int J Agric For Life Sci PB - Volkan OKATAN WT - DergiPark SN - 2602-4381 SP - 21 EP - 26 VL - 10 IS - 1 LA - en AB - Bakanae disease, caused predominantly by Fusarium fujikuroi, is an important seed-borne disease of rice that leads to serious yield losses and poses increasing management challenges due to fungicide resistance and limited use of certified seed. This study aimed to determine the thermal sensitivity and in vitro thermal death range of F. fujikuroi by evaluating the effects of different hot water temperature–time combinations on conidial germination and mycelial growth. A highly virulent isolate of F. fujikuroi was exposed to temperatures ranging from 50 to 60 °C for 5, 10, 15, and 20 min. Spore germination and mycelial growth were assessed on PDA, and inhibition percentages were statistically analyzed. Spore germination decreased progressively with increasing temperature and exposure time, with complete inhibition observed at ≥58 °C for all exposure durations and at 57 °C for prolonged treatment. Mycelial growth showed greater thermal tolerance, with total inhibition achieved at 59–60 °C for all exposure times and at 58 °C after 20 min. Overall, spore germination was more sensitive to heat than mycelial growth. These results provide essential baseline information for developing hot water seed treatment protocols and support the potential of thermotherapy as an effective, non-chemical approach for managing rice bakanae disease. KW - Fusarium fujikuroi KW - Bakanae disease KW - Rice KW - Thermoterapy KW - Seed-borne diseases N2 - Bakanae hastalığı, ağırlıklı olarak Fusarium fujikuroi tarafından oluşturulan, çeltikte önemli verim kayıplarına yol açan tohum kaynaklı bir hastalık olup; fungisitlere karşı gelişen direnç ve sertifikalı tohum kullanımının sınırlı olması nedeniyle giderek artan yönetim sorunları oluşturmaktadır. Bu çalışmada, farklı sıcak su sıcaklık–süre kombinasyonlarının konidiyum çimlenmesi ve miselyal gelişim üzerine etkileri değerlendirilerek F. fujikuroi’nin termal duyarlılığının ve in vitro termal ölüm aralığının belirlenmesi amaçlanmıştır. Yüksek virülense sahip bir F. fujikuroi izolatı, 50–60 °C sıcaklık aralığında 5, 10, 15 ve 20 dakika sürelerle uygulanmıştır. Spor çimlenmesi ve miselyal gelişim PDA besiyerinde değerlendirilmiş, inhibisyon yüzdeleri istatistiksel olarak analiz edilmiştir. Spor çimlenmesi, sıcaklık ve maruz kalma süresinin artmasıyla kademeli olarak azalmış; tüm uygulama sürelerinde ≥58 °C’de ve 57 °C’de ise uzun süreli uygulamalarda tamamen engellenmiştir. Miselyal gelişim daha yüksek bir termal tolerans göstermiş; tüm uygulama sürelerinde 59–60 °C’de ve 58 °C’de 20 dakikalık uygulama sonrasında tamamen inhibe edilmiştir. Genel olarak, spor çimlenmesinin miselyal gelişime kıyasla ısıya daha duyarlı olduğu belirlenmiştir. Elde edilen bulgular, sıcak su ile tohum uygulama protokollerinin geliştirilmesi için temel bilgiler sunmakta ve termoterapinin çeltikte bakanae hastalığının yönetiminde etkili ve kimyasal olmayan alternatif bir yaklaşım olarak potansiyelini desteklemektedir. CR - Amatulli, M. T., Spadaro, D., Gullino, M. L., Garibaldi, A. (2010). Molecular identification of Fusarium spp. associated with bakanae disease of rice in Italy. Plant Pathology, 59, 839–844. CR - Amoah, B. K., Rezanoor, H. N., Nicholson, P., & Macdonald, M. V. (1995). Variation in Fusarium species causing bakanae disease of rice. Plant Pathology, 44, 562–568. CR - Agustı-Brısach, C., Pe´ Rez-Sıerra, A., Armengol, J., Garcı´A-Jıme´Nez, J., Berbegal, M., (2012). Efficacy of hot water treatment to reduce the incidence of Fusarium circinatum on Pinus radiata seeds, Forestry; 85, 629–635. CR - Bazie, S., Ayalew, A., & Woldetsadik, K. (2014). Hot water treatment for the control of anthracnose (Colletotrichum musae) of banana. Crop Protection, 66, 127–134. CR - Choi, H. W., Hong, S. K., Lee, Y. K., Kim, W. G., & Chun, S. C. (2018). Taxonomy of Fusarium fujikuroi species complex associated with bakanae disease of rice in Korea. Plant Pathology Journal, 34, 322–336. CR - Copçu, M., Karaca., İ., (1983). İnvestigations on the determination of rice diseases caused by fungi, their distribution, prevalance and incidence, overwintering in the Aegan Region of Turkey. J. Turkish Plant Path. 12, 61-71s. CR - Desjardins, A. E., Plattner, R. D., Nelson, P. E., (1997). Production of fumonisin B1 and moniliformin by Gibberella fujikuroi frıom rice various geographic areas, Appl. Env. Microb. 63:1838-1842p. CR - Desjardıns, A.E., Manandhar, H.K., Plattner, R.D., Manandhar, G.G., Polıng, S.M., Maragos, C.M., (2000). Fusarium species from Nepalese rice and production of mycotoxins and gibberellic acid by selected species, Applied and Environmental Microbiology, vol:66 no:3:1020-1025p. CR - Eğerci, Y., Kınay-Teksür, P., Uysal-Morca, A., (2020a). First Report of Rice Bakanae Disease Caused by Fusarium fujikuroi Nirenberg in Turkey, Journal of Plant Pathology, (https://doi.org/10.1007/s42161-020-00604-4). CR - Eğerci, Y., Kınay-Teksür, P., Uysal-Morca, A., (2020b). First report of Bakanae disease caused by Fusarium proliferatum on rice in Turkey. J Plant Dis Prot https://doi.org/10.1007/s41348-020-00369-z. CR - FAO, (2025). Food and Agriculture Organization of The United Nations, http://faostat.fao.org CR - Gramaje, D., Armengol, J., Pérez-Sierra, A. (2009). Effect of hot-water treatments in vitro on conidial germination and mycelial growth of grapevine trunk pathogens, Plant Disease, 93, 950–956. CR - Gramaje, D., Alaniz, S., Abad-Campos, P., García-Jiménez, J., Armengol, J. (2010). Effect of hot-water treatments on Phaeoacremonium spp. and Cylindrocarpon spp., Plant Pathology, 59, 106–114. CR - Hajra, K. K., Ganguly, L. K., Khatua, D. C., (1994). Bakanae disease of rice in the West Bengal., J. Mycop. Res. 32(2):92-99p. CR - Jeon, Y., Yu, S., Lee, Y., Park, H., Lee, S., Sung, J.S., (2013). Incidence, molecular characteristics and pathogenicity of Gibberella fujikuroi species complex associated with rice seeds from Asian countries, Mycobiology, 41(4):225-233. CR - Kumar Reddy, B. (2022). Thermotherapy for management of seed-borne fungal pathogens: A review. Journal of Plant Pathology, 104, 1–14. CR - Malonek, S.C., Bornberg-Bauer, E., Rojas, M.C., Hedden, P., Hopkıns, P., Tudzynskı, B., (2005). Distribution of gibberellin biosynthetic genes and gibberellin production in the Gibberella fujikuroi species complex, Phytochemistry, 66:1296-1311p. CR - Neri, F., Mari, M., Brigati, S., Bertolini, P. (2009). Control of Neofabraea alba by plant volatile compounds and hot water, Postharvest Biology and Technology, 51, 26–34. CR - Ora, N., Faruq, A. N., Islam, M. T., Akhtar, N., Rahman, M. M. (2011). Detection and identification of seed borne pathogens from some cultivated hybrid rice varieties in Bangladesh. Middle-East Journal of Scientific Research, 10, 482–488. CR - Oruç, H.H., (2006). Mikotoksinler ve tanı yöntemleri, Uludag Üniv. vet. med. 24:105-110s. CR - Ou, S. H. (1985). Rice diseases (2nd ed.). Commonwealth Mycological Institute, Kew, UK. CR - Pra, M. D., Tonti, S., Pancaldi, D., Nipoti, P., Alberti, I. (2010). First report of Fusarium andiyazi associated with bakanae disease of rice in Italy. Plant Disease, 94, 1070. CR - Rotter, B., Prelusky, D.B., Sharma, R.C., Chahal, H.S., (1996). Seed health studies on parental lines of hybrid rice. Seed Research, 24(2)1:145-150p. CR - Singh, R., Sunder, S., Dodan, D. S. (1996). Yield losses caused by bakanae disease of rice. Indian Phytopathology, 49, 349–350. CR - Webster, R.K., (2004). Bakanae, How to manage the pests. Pest Management Guideliness. University of California Agriculture & Natural Resources. CR - Whiting, E. C., Khan, A., & Gubler, W. D. (2001). Effect of temperature and water potential on survival and mycelial growth of Phaeomoniella chlamydospora and Phaeoacremonium spp., Plant Disease, 2001(85): 195-201. CR - Zainudin, N. A. I. M., Razak, A. A.,Salleh, B. (2008). Bakanae disease of rice in Malaysia and Indonesia: Etiology of the causal agent based on morphological, physiological and pathogenicity characteristics. Journal of Plant Protection Research, 48, 475–485. UR - https://doi.org/10.66598/ijafls.1866708 L1 - https://dergipark.org.tr/en/download/article-file/5618571 ER -