Identification of potential donors and QTLs for resistance to false smut in a subset of rice diversity panel Shridhar Shivakumar Hiremath & Dharminder Bhatia & Jyoti Jain & Mandeep Singh Hunjan & Rupinder Kaur & Najam Waris Zaidi & Uma Shankar Singh & Bo Zhou & Jagjeet Singh Lore Accepted: 17 November 2020 # Koninklijke Nederlandse Planteziektenkundige Vereniging 2020 Abstract False smut of rice caused by Ustilaginoidea virens (Cooke) Takahashi (teleomorph Villosiclava virens) has emerged as a serious concern in rice produc- tion. While variation for resistance exists in rice germ- plasm, most of the cultivated varieties are susceptible to false smut. A total of 125 diverse lines from global rice diversity panel were screened for resistance to false smut along with susceptible checks GSR123 and PR116, under natural hot spot for 3 years at two different loca- tions and artificial inoculation conditions in a fourth consecutive year. False smut resistance was recorded based on infected panicles per plants (IPP), number of smut balls per plant (NSBP) and a disease score (DS). Of 125, 21 germplasm lines showed high level of resis- tance in all the years under natural hot spot as well as artificial inoculation conditions whereas 31 germplasm lines showed moderate resistance. Genome wide asso- ciation study for false smut related traits identified sig- nificant associations on chromosomes 2, 3, 6, 9 and 11 for IPP. Similarly, significant associations for NSBP were identified on chromosomes 3 and 8 and DS on chromosomes 3, 4 and 11. Most of these QTLs were found to be associated with all the traits. The study highlights the potential donors for resistance to false smut that could be utilized in rice breeding programme. The identified QTLs could be the potential candidate regions for further studying the false smut resistance. Keywords False smut . Rice diversity panel . Resistance . GWAS . QTL Introduction Rice (Oryza sativa L.), “the global grain” has high economic importance and widely consumed cereal by more than half of the world ’ s population. The burgeoning population, climate change and yield losses due to biotic and abiotic stresses are affecting the growth and production of the rice crop. False smut of rice caused by Ustilaginoidea virens (Cooke) Takahashi (teleomorph Villosiclava virens) (Tanaka et al. 2008) has emerged as an economically important constraint to the global rice production in the recent decades (Zhou et al. 2008). It not only affects the rice production but also impairs the rice grain quality by producing antimi- totic cyclic peptides called ustilotoxin (Li et al. 1995). This mycotoxin is a threat to food safety and is poison- ous to humans and livestock (Nakamura et al. 1994). The pathogen replaces all or part of the kernel with an abundant mass of yellow-dark green spores and culmi- nates with velvety smut ball formation. The sori of U. virens erupt through the palea and lemma (Brooks et al. 2010). Ultimately, the loss in grain yield is due to a reduction in test weight of grains, chaffiness and sterility of spikelet neighbouring the smut balls (Ladhalakshmi Eur J Plant Pathol https://doi.org/10.1007/s10658-020-02172-w S. S. Hiremath : D. Bhatia (*) : J. Jain : M. S. Hunjan : R. Kaur : J. S. Lore (*) Punjab Agricultural University, Ludhiana 141004, India e-mail: d.bhatia@pau.edu e-mail: jagjeetsingh-pbg@pau.edu N. W. Zaidi : U. S. Singh : B. Zhou International Rice Research Institute, Manila, Philippines