| Ginkgo biloba has high economic value and research value, such as for timber, medicinal andornamental uses.In this study, 184 individuals derived from Ginkgo biloba F1 family were used as the mapping population. SSR, SRAP and AFLP markers were used to construct the genetic maps to lay the foundation of ginkgo high-density genetic map construction, QTL mapping and marker-assisted selection. The main results are as follows:317 pairs of SSR primers(including 41 pairs of EST-SSR and 276 pairs of genomic SSR) were designed using ginkgo EST sequences and genomic sequences from 454 GS FLX platforms. 1122 pairs of ginkgo SSR primers were screened, and 60 pairs of polymorphic SSR markers(including 6 pairs of EST-SSR and 54 pairs of genomic-SSR) were developed for constructing a genetic map. These markers will provide a general source for the further studies in ginkgo. There is a potential value in the use of the 917 pairs of SSR primers, which produced a clear amplification product.A total of 1122 pairs of ginkgo SSR primers(including previously developed 573 SSR and 549 SSR designed in the study), 160 pairs of SRAP primers and 160 pairs of AFLP primers were screened in the two parents and four F1 individuals. 116 pairs of SSR(including 45 pairs of EST-SSR and 71 pairs of genomic SSR), 58 pairs of SRAP primers and 68 pairs of AFLP primers yielded 10.33%, 36.25% and 42.5% polymorphisms, respectively. 58 pairs of SRAP and 8 pairs of AFLP produced 118(2 loci/primer) and 37 polymorphic loci(4.6 loci/primer).265 polymorphic loci, including 116 SSRs, 58 SRAPs and 20 AFLPs, were obtained for constructing a genetic map. The genetic map identified 34 linkage groups containing 143 markers, using JoinMap v4.0. There were 17 linkage groups which had more than 4 markers, 7 triplets and 10 doublets. The map had a total length of 1929 cM, with an average length of 56.74 cM and a range of 14.4 cM to 181 cM. The length of marker intervals averaged 12.61 cM. The genome size of Ginkgo biloba was estimated at 2370.43 cM, and the genome coverage was estimated to be 81.38%. An artificially controlled ginkgo F1 hybrid mapping population was first used in construction of the genetic map of Ginkgo biloba, using SSR, SRAP and AFLP.The function of ginkgo EST sequences were analyzed, and the results suggested that some of the genes may be associated with GA-induce protein, nitrite transporter protein, a nuclear localization These markers are located in linkage group GB-1, GB-2, GB-4, GB-5, GB-10, GB-11, GB-12, GB-19, GB-20, GB-21, GB-24, GB-26, GB-28, GB-30, GB-33 and GB-34. The effects of these microsatellites on morphological traits of Ginkgo biloba in the full-sib offspring was analyzed using the GLM procedure of SPSS software. It showed that 6 and1 SSR markers were significantly correlated with the total leaf numbers and the annual growth of height in full-sib offspring. Split up sentenceGb_gSSR213 and Gb_eSSR367 were significantly correlated with both total leaf numbers and growth of height. This research might be useful for the QTL mapping and marker assisted selection for important growth traits. |
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