Study On Moleculer Markers Linked To Orange Head Leaf Gene (or) In Chinese Cabbage

Doubled haploid population was obtained from F1 between white-head lines 91-112 and orange-red head lines T12-19 by microspore culture. Bulked segregant analysis was employed to identify molecular markers linked to orange head leaf color gene (or) based on RAPD and AFLP in Chinese cabbage with this doubled haploid (DH) population. The linked markers identified were transferred into SCAR markers.The availabilty of these SCAR markers for marker-assisted selection was investigated in 110 different incompatibility breeding lines of Chinese cabbage. The results are as follows:Of 300 random primers screened, 7 showed polymorphism between two parents and two pools. One marker S1338₆₅₆ was identified to be linked to or gene in DH population. The genetic distance is 8cM.Among 256 pairs of PstI /Mse I AFLP primers, 22 showed polymorphism between two parents and two pools. One marker P67M54₁₇₂ was identified to be linked to or gene in DH population. The genetic distance is 13cM.RAPD marker S1338₆₅₆ and AFLP marker P67M54₁₇₂ were sequenced and successfully transferred into SCAR markers-SCOR₂₀₄ and SCOR₁₂₇ individually. The accuracy of 92% and 90% with marker identification were observed when compared with the results of head leaf colour in field condition among 100 DH lines. Furthermore, the accuracy of 90% and 89.1% were obtained when 110 different incompatibility breeding lines of Chinese cabbage were used to be investigated with two SCAR markers, indicating that these two SCAR makers could be used in marker-assisted-selection in orange head breeding programs of Chinese cabbage.