一个萝卜绿皮新基因GST1的遗传定位OA北大核心CSTPCD

To well understand of the formation mechanism of radish skin color and to develop related molecular markers for radish breeding,genetic populations were created by crossing the green-skinned radish G-2 with the white-skinned radish W-1,and the genetic rule of green skin was clarified.By combining bulked segregant analysis with RNA-seq technology(BSA-seq),the chromosome that carrys the locus controlling green skin was identified,then the green skin gene was mapped using the developed molecular markers.The results showed that the taproots of F1 plants derived from G-2 and W-1 exhibited an intermediate color(light green)compared to their parent plants.The F2 population appeared taproots with green-skinned,intermediate color-skinned,and white-skinned,approximately in a ratio of 1∶2∶1(χ2=3.21,P>0.05),indicating that the green skin phenotype demonstrated incomplete dominance in the genetic offspring and was controlled by one single major locus,provisionally designated as GST1(Green-Skinned Taproot 1).BSA-seq results showed that 1 827 single nucleotide polymorphisms(SNPs)exhibited polymorphism between the green-and white-skinned radish bulks from the G-2×W-1 F2 population.Of these SNPs,31.86%were located on chromosome R01,primarily distributed within the physical region of 0-5 Mb at the terminal of the short arm.Molecular markers were developed in proximity to this section,ultimately leading to the mapping of GST1 within the genetic interval between the flanking markers sxau30 and sxau34,with the genetic distances of 6.4 and 8.3 cM,respectively.This corresponds to the physical section R01:2.93-8.99 Mbp of the reference genome for the radish variety Radicula.A total of 210 annotated high-confidence genes expressed in taproot skin were identified within this interval,of which 44 exhibited significantly different expression between the green-and white-skinned bulks.Quantitative real time-PCR(qRT-PCR)validation was performed on four candidate genes that may be involved in the chlorophyll synthesis or metabolism pathway,confirming that their expression levels aligh with the RNA-seq results.These results lay a foundation for elucidating the mechanisms behind radish green skin and provide new markers for molecular breeding of skin color.