2022年8约30日，中国农业科学院蔬菜花卉研究所在园艺领域顶刊Horticulture Research（2023 IF=8.7）上发表了题为“Introgression of clubroot resistant gene into Brassica oleracea L. from Brassica rapa based on homoeologous exchange“的研究论文，论文第一作者为朱明钊博士，通讯作者为吕红豪研究员和王勇副研究员。

根肿病是甘蓝的一种土传病害，是甘蓝的三大病害之一，但是甘蓝中尚未发现有效抗源，而白菜中已定位出较多抗根肿病位点。作者通过两种方法获得抗根肿病的甘蓝育种材料，1是利用Ogura CMS育性恢复系恢复了含有CRA的Ogura CMS材料，2是通过远缘杂交的方法，将白菜中的抗根肿病基因导入甘蓝，通过小孢子培养、胚挽救等手段成功获得了含有三个抗根肿病基因的甘蓝材料。

Figure 1. Flow cytometric determination of DNA content karyotype analysis of microspore individuals. a ‘ZM1’ (control). b Haploid. c Diploid. d Tetraploid. e Chimera. f ‘19CR2–7’.

Figure 2. Flow cytometric determination of DNA content and karyotype analysis of distant hybridization offspring. a ‘BR1’. b ‘16Q235’. c Allodiploid F1. d Allotetraploid F1. e T riploid BC1. f BC2. g ‘ZF1’. h ‘ZF10’.

Figure 3. Morphological variations of seedling of allotetraploid plants (F1, B C1, B C2, and their parents). a ‘16Q235’. b ‘BR1’. c Allodiploid F1. d Allotetraploid F1. e BC1. f BC2

Figure 5. Semi-quantitative RT -PCR analysis of CRa for ‘19CR1–10’, ‘19CR2–7’, and ‘19CK2’. M, Marker. 1–10 individuals of corresponding lines. a ‘19CR1–10’. b ‘19CR2–7’. c ‘19CK2’

Figure 6. Identification of resistant genotypes against P . brassicae. a ‘ZM1’ (negative control). b ‘ZM2’ (positive control). c ‘BR1’. d ‘16Q235’. e BC1. f BC2.

Figure 7. Identification of polymorphic DNA markers of exogenous fragment in cabbage genome. M, Marker. K1-F29, the name of InDel markers. KB, CRa-specific marker KBrH129J18. For each marker, the order of the samples was ‘19CR2–7’, ‘19CK2’, ‘BR1’, and cabbage.

Figure 8. Model illustrating the introgression of an exogenous fragment from Brassica rapa into cabbage chromosome.

Figure 9. Left and right border sequences of the fragment from Brassica rapa in the cabbage genome.

Figure 10. Segmental collinearity analysis of Brassica rapa and cabbage genomes.

Figure 11. Analysis of collinearity between Brassica rapa A03 chromosome and corresponding chromosomes in cabbage genomes. The gray background indicates the position of the B. rapa-derived fragment inserted into the chromosome of cabbage.

Figure 12. Manhattan plot showing genome-wide association study (GW AS) results for the location of CRa. The dotted line denotes the lower threshold for genome-wide significance.

Figure 13. The pedigree map illustrating the creation process of cabbage DH lines.