Kubo et al./Breeding Science doi:10.1270/jsbbs.18126

Supplemental Table 1. Detailed list of B. rapa samples used in this study Type Cultivar or line namea Note Source Japanese nabana, "flower-bud type" Cultivar CR Hanakanzashi Hybrid CR cultivarb Marutane Seed Co., Ltd., Kyoto, Japan CR Hanamatsuri Hybrid CR cultivarb Marutane Seed Co., Ltd., Kyoto, Japan CR Hananomai Hybrid CR cultivarb Marutane Seed Co., Ltd., Kyoto, Japan CR Kyobare Hybrid CR cultivarb Marutane Seed Co., Ltd., Kyoto, Japan CR Kyonoharu Hybrid CR cultivarb Marutane Seed Co., Ltd., Kyoto, Japan Eika Hybrid CR cultivarb Sakata Seed Corporation, Yokohama, Japan Hanamusume Hybrid CR cultivarb Sakata Seed Corporation, Yokohama, Japan Shunka Hybrid CR cultivarb Nihon Nousan Shubyo Co., Ltd., Minowa, Nagano, Japan Shunrai Hybrid CR cultivarb Sakata Seed Corporation, Yokohama, Japan 88 go no. 20 Hybrid cultivar Sakata Seed Corporation, Yokohama, Japan Hanaguruma Hybrid cultivar Marutane Seed Co., Ltd., Kyoto, Japan Hanakazari Hybrid cultivar Sakata Seed Corporation, Yokohama, Japan Kanzaki 21 go Hybrid cultivar Sakata Seed Corporation, Yokohama, Japan Shuka Hybrid cultivar Takii & Co., Ltd., Kyoto, Japan Soyo 1 go Hybrid cultivar Sakata Seed Corporation, Yokohama, Japan Toka Hybrid cultivar Takii & Co., Ltd., Kyoto, Japan Ezuki Non-hybrid cultivar Sakata Seed Corporation, Yokohama, Japan Kaneki hanana Non-hybrid cultivar Sakata Seed Corporation, Yokohama, Japan Kanzaki natane Non-hybrid cultivar Taniguchi Hikobe Shouten, Ohtsu, Japan (JP25960) c Kurokawa kanzaki Non-hybrid cultivar Takii & Co., Ltd., Kyoto, Japan Kyoto Fushimi kanzaki Non-hybrid cultivar Takii & Co., Ltd., Kyoto, Japan Nabana (kanzaki hanana) Non-hybrid cultivar Tohoku Seed Co., Ltd., Utsunomiya, Japan Shokuyo nanohana Non-hybrid cultivar Takii & Co., Ltd., Kyoto, Japan Shunyo Non-hybrid cultivar Sakata Seed Corporation, Yokohama, Japan Soshun nabana Non-hybrid cultivar Sakata Seed Corporation, Yokohama, Japan

Landrace Awa zairai Landrace in Chiba Prefecture Warm Region Horticulture Institute, Chiba Prefectural Agriculture and Forestry Research Center, Tateyama, Japan Nagaokakyo Landrace in Nagaokakyo, Kyoto Supplied by an anonymous, nabana farmer Prefecture

Japanese nabana, "stem-and-leaf type" Cultivar Fukitachina (kasamai-kei) Non-hybrid cultivar Matsushita Seed Co., Kanazawa, Japan Himeji wakana Non-hybrid cultivar Sanyo Seed Co., Ltd., Himeji, Japan Kukitachina Non-hybrid cultivar Tohoku Seed Co., Ltd., Utsunomiya, Japan Nagaokana Non-hybrid cultivar Komesan Corporation, Nagaoka, Japan Orina Non-hybrid cultivar Ogura Jutaro Shouten, Sakata, Japan (JP25938)c Wakana Non-hybrid cultivar Osaka Sosai Genshu Kenkyukai, Habikino, Japan Wakana (kurona) Non-hybrid cultivar Takada Seed Co., Ltd., Osaka, Japan (JP25969)c

Landrace Fukidachi (kukidachi) Landrace in Nango, Hachinohe, Hachinohe Agriculture Improvement Extension Center, Aomori Prefecture Hachinohe, Japan (JP25936)a Katsuyama mizuna 1 go Landrace in Fukui Prefecture Fukui Agricultural Experiment Station, Fukui, Japan (JP25937)c Natane G Landrace in Kamitakano, Kyoto, Biotechnology Research Department, Kyoto Prefectural Kyoto Prefecture Agriculture, Forestry and Fisheries Technology Center, Soraku-gun, Japan Orina (fukitachi) Landrace in Toyama Prefecture Kurobe Agriculture Improvement Extension Center, Kurobe, Japan (JP25940)c Sangatsuna Landrace in Kitakuwada, Nantan, Mr. H. Shimoizu, Nantan, Japan (JP25972)c Kyoto Prefecture

Chinese flowering cabbage, "zicaitai" (subsp. chinensis var. purpuraria ) Hon tsai tai Non-hybrid cultivar Sakata Seed Corporation, Yokohama, Japan Kosaitai Non-hybrid cultivar Tohoku Seed Co., Ltd., Utsunomiya, Japan Kosaitai (beni nabana) Non-hybrid cultivar Takii & Co., Ltd., Kyoto, Japan Chinese flowering cabbage, "cai-xin", "caitai" or "" (subsp. chinensis var. parachinensis ) Wasekei saishin Non-hybrid cultivar Takii & Co., Ltd., Kyoto, Japan

European flowering cabbage, "broccoletto", " raab" or "" (subsp. sylvestris var. esculenta ) Cima di rapa Non-hybrid cultivar Fujita Seed Co., Ltd., Osaka, Japan

Neep greens (var. oleifera ) Shiroguki hatakena Non-hybrid cultivar Takii & Co., Ltd., Kyoto, Japan

Turnip (subsp. rapa ) CR Omasa Hybrid CR cultivarb Musashino Seed Co., Ltd., Tokyo, Japan Golden ball Non-hybrid cultivar Catros Gerand SAS, Carbon Blanc, France

Non-heading , "Pak choi" (subsp. chinensis ) Pak choi Non-hybrid cultivar Takii & Co., Ltd., Kyoto, Japan

Non-heading Chinese cabbage, "" or "wutacai" (subsp. narinosa ) Taasai Non-hybrid cultivar Takii & Co., Ltd., Kyoto, Japan

Heading Chinese cabbage (subsp. pekinensis ) Muso Hybrid cultivar Takii & Co., Ltd., Kyoto, Japan a Cultivars are sorted according to their categories (CR/non-CR and hybrid/non-hybrid). b CR: clubroot resistant. c Seeds stocked at Genetic Resources Center, National Agriculture and Food Research Organization, Tsukuba, Japan (accession nos. in perentheses). Supplemental Table 2. List of B. rapa SSR markers analyzed Allelic range SSR name Primer sequence (5'-to-3') A a A b observed (bp) R BRMS-033 Forward: gcggaaacgaacactcctcccatgt 217-360 12 6.740 Reverse: cctccttgtgctttccctggagacg BRMS-085 Forward: actccacactctcacttcctctatt 153-378 8 3.651 Reverse: ttacgcttgtttctgtttttgaata BRMS-158 Forward: aaaagacaaaaccatccaaacacta 207-240 17 7.995 Reverse: aagcctttttgaacttctctgtgat BRMS-194 Forward: gatggtggtgagtttataagctctg 177-193 5 3.279 Reverse: cttcaaagcacttctccttcctctc BRMS-208 Forward: ctctctctatcgtcttctcagatgg 220-238 3 2.915 Reverse: gtttaagcctcttctgaaacctctc BRMS-220 Forward: cctgaatgttttaggagtgtacttc 116-126 5 3.264 Reverse: ttgcttcagaaggaaggtcaggaga BRMS-253 Forward: ggactactctttgaagcgatacttg 235-258 9 4.850 Reverse: aatagaatcacaatgcactgaaaca BRMS-269 Forward: aattttcaacgccttcatcctgt 286-313 11 5.639 Reverse: ggtgaatgcatcagtcgacataact a Number of alleles per locus. b Allelic richness based on minimum sample size of 13 individuals. Supplemental Table 3. Assumption of suitable number of subpopulations (K ) for population structure analysis LnP (K )b K a Ln' (K )c |Ln'' (K )|d K e Mean S.D. 1 -20189.020000 0.042164 N.A.f N.A.f N.A.f 2 -18298.563636 0.756667 1890.456364 1104.072727 1459.125665g 3 -17512.180000 1180.673361 786.383636 240.936364 0.204067 4 -16484.860000 69.520136 1027.320000 566.220000 8.144691 5 -16023.760000 237.234461 461.100000 225.730000 0.951506 6 -15336.930000 185.765001 686.830000 357.380000 1.923828 7 -15007.480000 344.935681 329.450000 N.A.f N.A.f a K : number of subpopulation. b LnP (K ): mean and standard deviation (S.D.) of likelihood over 10 runs for each K . c Ln' (K ): mean difference between successive likelihood values of K . d |Ln'' (K )|: absolute value of the difference between successive values of Ln' (K ). e K : mean of |Ln'' (K )| over 10 runs divided by S.D. of LnP (K ). K = Mean(|L'' (K )|)/S.D.(LnP (K )) f N.A.: not analyzed. g The maximum value of K at K = 2 is indicated with red text. Supplemental Table 4. Genotypes of six clubroot resisitance (CR) markers in CR and non-CR B. rapa lines Resistance locus and markerb CRb Crr1 Crr2 Crr3 Linea B1210c KB59N06c BSA7c B359c 523A1Rc OPC11-2Sd CR Shinki (CRb ) 187/211 265/270 357 228/235 162 0.9 Control CR linea G004 (Crr1, Crr2 ) 211 262 332 149 140 0.9 N-WMR-3 (Crr3 ) Nulle 224 332f 149f 162 1.2 Non-CR nabana Hanakazari 211 251/257 357 227/228, 228 162 0.9 cultivar CR Hanakanzashi 187 241/270 332/357 149/228 162 0.9 CR Hanamatsuri 187 228/270 332/357 149/228 162 0.9 240/270, 332, CR Hananomai 187 257/270, 149/228 162 0.9 332/357 270 CR Kyobare 187 270 332 149/228 162 0.9 234/270, CR Kyonoharu 187 332/357 149/228 162 0.9 241/270 CR nabana Eika 187 257/270 332/357 149/228 162 0.9 cultivar 226/270, Kanzaki 21 go 187 332 149/228 162 0.9 270 234/270, Shunka 187 332/357 149/228 162 0.9 241/270 187, 241/270, Shunrai 332/357 149/228 162 0.9 187/211 268/270 227/228, 140/162, Hanamusume 187 257/272 357 0.9, nulle 228 161/162 a Resistance gene(s) contained in each control line are indicated in parentheses. b Alleles detected in each line are indicated with band sizes, in which homozygote and heterozygote are represented with single and dual (two numbers connected with slashes) numbers, respectively. All detected alleles are listed up when more than one kind of allele was detected. Resistance allele is indicated with red text. c Band sizes (bp) were analyzed on a DNA sequencer, whose sizes were larger than those in references (Suwabe et al . 2006, Kato et al . 2013, Matsumoto et al . 2017) because of tag sequences for a post-labeling (Shimizu and Yano 2011). d Approximate band sizes (kb) were estimated in a 1.5% agarose gel. e Null allele, no PCR product was detectable. f Because the CR trait of N-WMR-3 was independent of Crr1 and Crr2 (Hirai et al . 2004), this allele is likely to have occurred accidentally.