Bakanae disease, caused by various Fusarium species, poses a significant threat to global rice production, with its incidence increasing in major rice-producing regions. Currently, no rice varieties exhibit complete resistance to this disease. Enhancing resistance in rice cultivars could serve as a cost-effective and sustainable alternative to fungicide application. Developing resistant rice varieties may offer a practical solution to mitigate yield losses and reduce dependency on chemical treatments. ‘Jinokchal’ was derived from the cross between ‘Milyang299’, which harbors bakanae disease-resistant QTL qBK1. and ‘Baekokchal’ in 2014. A promising line, YR31624-5B-2, was then selected and designated as ‘Milyang366’ in 2019. The local adaptability test of ‘Milyang366’ was conducted at five locations from 2020 to 2022, and the cultivar was subsequently named ‘Jinokchal. ’ The heading date of ‘Jinokchal’ was August 13, classifying it as a medium-late maturing cultivar. The culm was 77 cm long and had 108 spikelets per panicle. The 1,000 grain-weight of brown rice is 22.7 g, which is heavier than that of ‘Sinseonchalbyeo’. This variety is resistant to blast, rice stripe virus, and bacterial blight, but susceptible to insect pests. The yield potential of ‘Jinokchal’ was approximately 497 kg/10a at the ordinary fertilizer level in the local adaptability test over three years. ‘Jinokchal’ is moderately resistant to bakanae disease and harbors the qBK1 gene derived from the tong-il type rice ‘Shingwang’ (Registration No. 8135).

Bakanae disease, also known as the foolish seedling disease, caused by Gibberella fujikuroi, is a serious issue in Korea. Since 2007, there has been a rapid increase in the occurrence of bakanae disease; this has caused severe yield loss to rice farmers every year. The most reliable and economical solution for managing bakanae disease is to cultivate resistant varieties; however, there are only a few rice varieties in Korea that can withstand this disease. Therefore, this study aimed to evaluate the resistance of 61 major rice varieties which account for 89% of the total rice cultivation area. Only six varieties showed intermediate or higher resistance to bakanae disease; this included Anpyeong and Samkwang. The genetic inconsistency between the bioassay results and the allele types of 12 molecular markers (associated with four QTLs) ranged from 4.7% to 48.7%. Therefore, more accurate markers, such as gene-based markers, are essential for monitoring general breeding programs or gene pyramiding.

Bakanae disease is caused by several species of Fusarium and imposes serious limitations to rice production worldwide. The incidence of this disease is increasing in the top rice-growing countries. No rice variety has been found to be completely resistant to this disease. Thus, higher resistance to the disease may be a cost saving solution preferable to the application of fungicides. ‘Anpyeong’ was derived from the cross between ‘YR24982-9-1’ and ‘Saeilmi’ in 2012 and selected as the promising line, ‘YR30389-B-2GH-103’; it was further selected and designated as ‘Milyang 313’ in 2016. The local adaptability test for ‘Milyang 313’ was conducted at five locations from 2016 to 2018 and the cultivar was named ‘Anpyeong’. The heading date for the medium-late maturing cultivar ‘Anpyeong’ was August 13. The ‘Anpyeong’ culm was 77 cm long and had 115 spikelets per panicle. The brown rice 1,000 grain-weight was 22.2 g, which is higher than that of ‘Nampyeong’. This variety is resistant to blast disease and rice stripe virus, but susceptible to bacterial blight and insect pest. The potential ‘Anpyeong’ yield was approximately 562 kg/10 a at ordinary fertilizer level in the local adaptability test and for three years. ‘Anpyeong’ harboring the qBK1 gene derived from a tongil type rice ‘Shingwang’ is moderately resistant to bakanae disease (Registration No. 8135).

Bakanae disease is an important fungal disease caused by Gibberella fujikuroi. Incidence of rice bakanae disease creates serious problems in the foremost rice producing countries, affecting more or less all known rice cultivars. Breeding rice cultivars resistant to bakanae disease will thus be a cost-effective alternative to the application of fungicides. ‘MY299BK’ was derived from a cross between YR24982-9-1 and ‘Ilpum’ in 2008. A promising line, YR28297-1-38-1-1, was selected from among the progeny and designated ‘Milyang299’ in 2013. The local adaptability test of ‘Milyang299’ was carried out at five locations from 2014 to 2016 and named ‘MY299BK’. The heading date of ‘MY299BK’ was Aug. 15, typical for a medium-late maturing cultivar. Its culm was 71 cm long, there were 114 spikelets per panicle, and 1,000 grain-weight of brown rice was 23.4 g; these parameters were similar to those of ‘Nampyeong’. ‘MY299BK’ cultivar was resistant to blast and rice stripe virus, but susceptible to bacterial blight and insect pests. Its yield potential was about 566 kg/10 a at ordinary fertilizer level in a three-year-long local adaptability test. ‘MY299BK’ resistance to bakanae is conferred by the qBK1 gene derived from a tong-il type rice ‘Shingwang’ (Registration No. 7651).

Bakanae (foolish seedling) disease caused by Gibberella fujikuroi creates serious problems in the foremost rice growing countries. This study was conducted to identify new resistance genetic sources to Bakanae disease. Bioassay showed that 11 varieties including Gwangmyeongbyeo, Hawn, Wonseadaesoo, Erguailai etc. were resistant to bakanae disease among 254 rice germplasm. Mismatch ratio between phenotype on bakanae disease bioassay and allele type of RM9, a SSR marker closely linked the bakanae disease resistant QTL, qBK1, were 38.3%. These results suggest that RM9 might be used for selecting qBK1, but it cannot be used for wide range of rice germplasm. Resistant germplasm in this study might be have resistant genes different from qBK1. The eleven varieties resistant to selected in this study will be used to identify new resistant alleles or genes to improve bakanae disease resistance in rice.