| Cabbage (2x=18) the cruciferous cabbage Brassica species, is a widely grownvegetable in the world. with high economical and practical value. With the continuousimprovement of living standards, nutritional quality and health effects of vegetablecrops are high required. Brassica crops are recognized as one of anticancer vegetablesowe to glucosinolates. Therefore it has high value to breed cabbage varietes rich inglucosinolates. In this study, a high density molecular genetic linkage map of cabbagewas constructed using333SSR markers. The graphic materials were F5groupsobtained from continuous single grain selfing from F2, selfing by F1, F1hybrids fromthe two inbred lines parents which had distinct difference in fusarium wilt resistance,bolting time, glucosinolates content. On the basis, glucosinolates composition ofmatter content of132individuals were measured. The QTL mapping and analysis wasmade according to above materials. The main results are as follows:1. The construction of high-density genetic linkage map in head cabbageThe333SSR markers were conducted for genetic linkage analysis with Join Map3.0software, and LOD threshold was set as5.0. On the condition of the measuredLOD greater than or equal to LOD threshold value, a total of323markers get intolinkage group, and finally9chain linkage groups were partly named as LG1~LG9.The number of linkage groups was consistent with the9pairs chromosomes (2n=2x=18) of head cabbage. However, about three percent of the markers did not enter thelinkage groups, which covering786cM length of the entire genome. The averagedistance between markers reached2.43cM. The length of lock group ranged from60cM to114cM, and the number of markers was in the range of24to82. The numberof markers obtained the maximum value in LG1chain linkage group, whosemaximum density distance between the markers was less than1cM.2. QTL localization and analysis of related traits of head cabbage’s glucosinolatesThe QTL location of composition content of glucosinolates built map community(IBE, SIN, PRO, RAA, GBC and4ME) was performed by using constructedhigh-density genetic linkage map. These15QTL loci were retested by compositeinterval mapping (CIM) and found that eight QTL sites eventually did exist. The threeQTL loci associated with IBE, which qIBE-3-1, qIBE-3-2located on LG3corresponding with2nd physical chromosome of head cabbage; qIBE-6-1located onLG6corresponding with9physical chromosome of head cabbage, their LOD value were3.47,3.43,3.04respectively; additive effects were partly-1.125,-1.130,2.254;the contribution rate were partly9.2%,10.3%,11.9%, respectively. The other threeQTL sites were associated with SIN, PRO and RAA (qSIN-6-1, qPRO-6-1,qRAA-6-1), because these three points on the bit position was the same as LG6, andthe closely linked markers are also consistent with8C0141, indicating that the locussimultaneously control three kinds of characters coseparation. Their LOD values werepartly8.31,5.50,3.33; additive effects were partly-1.167,-0.799,1.353; contributionrates were partly19.3%,12.4%and6.7%. The last two QTL loci were associatedwith RAA, qRAA-3-1located on LG3(Ch2); qRAA-6-2located on LG6(Ch9), LODvalues were partly4.98and3.18; additive effects were partly1.485and1.034;contribution rate was10.6%and5.8%, respectively. Consequently, seven markers(OL09-A03, BoSF2242, BoSF2679, FIT0016,8C0141, FIT0034, FIT0424) wereeventually identified and they all can be used for assisted breeding of above fourkinds of glucosinolates related composition (IBE, SIN, PRO, RAA). |
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