Construction of a High-Density Genetic Linkage Map using Axiom Genotyping and Identification of QTLs for Wood Property, Growth and Male Flower Formation in Japanese Cedar (Cryptomeria japonica)

We constructed a high-density linkage map, and performed quantitative traits loci (QTL) analysis of the seventy traits related to wood property, growth and male flower formation using F1 population from a cross between plus-trees “Minaminasu2”and “Otawara1”. For the constructinglinkage map, approximately 70kSNPs, which were identified from ESTs collected from plural tissue, were genotyped using Axiom genotyping system. About 1.2k SNPs out of 70kSNPs was polymorphic between the parents. The linkage map of “Minaminasu2” consisted of 11 linkage groups of 1,403 loci spanning 1221.2cM and that of “Otawara1” consisted of 11 linkage groups of 1,297 loci spanning 1,282.3cM. The integrated map became 11linkage groups, which corresponds the chromosome number of C.japonica, of 2,045 loci spanning 1,330.2cM. The detected QTLs for traits related to wood property and growth were located various position in linkage groups on the both “Minaminasu2”and “Otawara1”map. The evident QTL that had relatively high QTL score (more than 4.0), for the GA-treated male flower formation was found on LG6 on the Otawara1 map.