| With the development of the world energy crisis increases seriously in recent years, shortrotation coppice willow which is of fast growth and high biomass, as an important biomassenergy tree specie, has been applied to bioenergy and biofuel preparation, etc. How to improvethe biological yield is concern the breeders focused on. S. erioclada, shrub, has wideapplication prospect as an important bioenergy tree specie, because it has many excellentproperties, such as fast growth, high biomass, calorific value, and so on. To reveal the geneticbasis of energy characteristics, density genetic map construction and QTLs mapping of thesetraits has very important significance and QTLs analysis is of great significance. This researchconstruct a linkage map based on amplified fragment length polymorphism and simplesequence repeat using280F1individuals derived from a cross between S. erioclada ‘P718’ and‘P718’. The growth triats, biomass and calorific value were measured for QTLs analysis. Theconclusion is as follows:（1）Fifty-four pairs of AFLP primers and36pairs of SSR primers were selected and usedthe construction of the genetic map in S. erioclada ‘P718’בP718’.3386makers weregenerated from54pairs of AFLP primers, including1027polymorphic makers.885makerswere accorded with Mendel’s law of segregation, and142makers were partial separation. In36pairs of SSR primers,17pairs were accorded with Mendel’s law of segregation, and18pairswere partial separation.（2）These902markers accorded with Mendel’s law were used for constructing geneticlinkage map using JoinMap4.0software.19major linkage groups,2small linkage group,7triplets and16doublets were got.609AFLP markers and8SSR markers were ordered on the19major linkage groups. The distance of linkage groups was between47.32cM and225.30cM. The total distance of linkage groups is2481.75cM, and the average distance is4.07cM.Estimated length of genetic map is2208.35cM. Map coverage rate is calculated according tothe method of Lange(1982) and Bishop(1983), and it is99.29%and99.98%, respectively. （3）Biennial tree height, ground diameter and stem sprounting of F1individuals weremeasured and QTLs analysed using MapQTL5.0software. QTLs associated with biennial treeheight has10at LG1, LG3, LG5, LG6and LG10, which can explain the phenotypic variationwere14.5%,22.0%,16.3%,37.9%,40.4%,14.0%,17.6%,16.9%,18.0%and28.5%respectively. QTLs associated with biennial ground diameter has10at LG3, LG4, LG5, LG6,LG10and LG16, which can explain the phenotypic variation were17.4%,20.0%,33.8%,26.4%,14.9%,22.7%,29.5%,18.2%,32.4%and45.6%respectively. QTLs associated withnumber of biennial branches has seven at LG1, LG3, LG10and LG11, which can explain thephenotypic variation of26.4%,13.4%,19.5%,29.9%,20.5%,15.1and23.5%respectively.（4）The annual average biomass per unit area and calorific value of F1individuals weremeasured and QTLs analysed for the first time. QTLs associated with biomass has7at LG3,LG5, LG10, LG14and LG19, which can explain the phenotypic variation were17.5%,30.4%,19.5%,45.4%,34.5%,17.9%,31.6%and52.9%respectively。QTLs associated with calorificvalue has four at LG2, LG3and LG12, which can explain the phenotypic variation were23.8%,12.9%,19.5%and17.2%, respectively.We constructed a densest genetic linkage map of Salix at home and abroad, and thecoverage of mapping is very high, almost covering the whole genome. QTLs analysis of thegrowth traits, biomass and calorific value and detection of loci controlling these traits locicould provide scientific theoretical basis for molecular marker assisted breeding for Salix,accelerate breeding research process and develop good Salix varieties of high yield and highbioenergy. |
