Genetic Linkage Map And QTL Mapping Of Oriental×Oriental Lily Population Using SSR And AFLP Markers

Lilium L. is a perennial ornamental bulbous, belonging to subclass Monocotyledonae and Liliaceae family, which consists of about 100 species and the genome of this flower is very repetitive and one of the largest among plants. One of the most important hybrids in Lilium L. is Oriental hybrid lily. Different combination of cross has been done in lily family, such as AA(Asiatic×Asiatic), AL(Asiatic×Longiflorum), OT(Oriental×Trumpet) etc. The OO(Oriental×Oriental) combination is a new one and has been done in our group.We selected SSR and AFLP markers to overlapping each other and also our group has developed 495 SSR primers and we used them to test in this population. Genetic linkage groups were created according to the haploid number of lily chromosomes(12 linkage groups). In this experiment the final F1 population, which creates a genetic linkage group was 100 individuals. For map construction JOINMAP 4.0 software by treating segregation data of markers as a CP(out breeder full-sib family) model was used. One of the most special advantages of this model is that it can generate a paternal, maternal and F1 progeny maps at a same time. The total of 30 genetic linkage maps were constructed, 12 linkage maps for both Lilium‘Sorbonne’(maternal maps) and Lilium‘Gaudi’(paternal maps) and 6 linkage maps for F1 hybrid progeny. After evaluation of ornamental traits, MapQTL 4.0 software was also used to find possible QTLs on these linkage maps. The main results are summarized as follows:1.A total of 940 primers were tested and the best ones which were 172 primer pairs including AFLP Marker and 76 SSR markers used for map construction and by used of these markers the total of 616 loci with 465 loci for AFLP marker and 151 loci for SSR marker were scored. To grouping the markers independence LOD(Log of Odds) was set from 2.0 to 10. After creating groups, the groups with LOD from 3.0 to 5.0 were used to construct linkage maps. The entire mapped length was 2144.2 cM. The overall number of mapped loci was 189 loci from which 142 loci were assessed by AFLP marker and 47 loci by SSR marker.2. The full length of linkage groups in maternal plant was 861.6 cM with 12 linkage groups. The minimum and maximum linkage groups distance for male plant also was 2.2 cM and 55.7 cM, respectively. The number of mapped loci for the maternal genetic linkage map was 52 loci with 42 loci for AFLP marker and 10 loci for SSR marker. In paternal maps which were 12 linkage groups the entire length of linkage groups was 676 cM and the number of mapped loci was 51 loci. The results showed that the total of 46 loci and 5 loci were scored by AFLP and SSR marker respectively. The minimum linkage group distance for female map was 0.1 cM while the maximum distance was 47.7 cM. In F1 progeny 6 linkage groups were found with the number of 86 completely assessed loci. The results also revealed that the number of AFLP marker scored loci was 54 loci and the number of SSR marker scored loci was 32 loci. The total length of linkage group for F1 progeny was 606.6 cM. The minimum and maximum linkage groups distance for F1 progeny also was 0.2 cM and 26.8 cM, respectively.3. The 8 QTL in this study was observed for the important traits, such as flower number. Each QTL locus explained the phenotypic variation of 2.4%~89.5%. The highest amount of LOD(35.21) was found in LG-F1P2 for FN4 QTL. For leaf number one QTL was mapped with LOD of 7.08 between 2 markers on the LG-M10 of maternal maps. The QTL for petal length was placed on the LG-F1P2 of the F1 hybrid maps on the E-CGC/M-CGC-4 primer combination. The petal width QTLs were mapped at a similar location as where a qualitative locus named LN was mapped on the LG-M10 of the maternal maps. PW2 QTL was also localized on the LG-F4 of the paternal maps.In this experiment 5 QTLs also were mapped for spot number in all F1 hybrids, paternal and maternal maps and for the spot size one QTL with the length of 51 cM was measured on the LG-M8 of the maternal maps. Plant height QTL with the LOD of 12.54 was mapped on the primer combination of E-CGC/M-CGC-4 on the LG-F1P2 of the F1 hybrid maps.