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Construction and application of a multifunctional and saturaded genetic map for coniferous species

Objective

The aims the project is to construct an ultra -high density linkage map hued map of pinups pilaster based on 12.000 all markers. And 100 published micro satellites (sir). This map will be placed on www and exploited to foul extent for comparative genome analyse and to analysis in different geneticbackrounds.four other published linkage maps in forest species will be aligned with the reverensemap. Based on reduced linkage maps derived from common subset of primer combination comparative genome analysis will be perfumed in different pines and related gymnosperms.qtlanalysis for important characters in different forest species will be performed and let effect and position compared. Allele-specific markers for importantqtls will be developed and their variability in local germplasm and breeding material will be analysed
A total of 2717 segregating fragments derived from 401 AFLP primer combinations (PCs) and 48 EST or SSR primer pairs (evaluation of nearly 300 EST/SSR primers) were identified in the Pinus pinaster reference population descending from the cross 0024 Landes x C803 Corsica. - Parental linkage maps of the reference population have been constructed based on these markers. 12 linkage groups with 30 to 96 markers each were obtained for each parent. - The availability of 79 anchor points based on fragments common to both parents and based on codominant SSR and EST markers allowed to determine homologous chromosomes for both maps and to construct one integrated High Density map. Total genome length of the integrated map is around 2000 cM including 1697 markers (141 markers per linkage group). A total of 34 SSR and EST loci are included in this map. Mapped marker numbers were lower than expected due to an increased degree of homozygousity in the parental trees. Our linkage map represents actually the map with the highest marker density in forest species. All results including parental AFLP profiles have been published on the WEB page: www.neiker.net/UHDfor - Using a common set of 25 AFLP-PCs as well as additional PCs and numerous EST and SSR markers, linkage maps in six different conifer populations were obtained (2 populations of Pinus radiata, 2 populations of P. sylvestris, one population of Pseudotsuga menziesii and Picea abies).

The individual parental and integrated linkage maps show a varying degree of saturation. They contain between 11 and 17 linkage groups and between 54 (Pseudotsuga, parental map) and over 750 markers (Picea, intgrated map). In accordance the map lengths vary between 500 and 2000 cM. - Based on co-dominant EST and SSR markers which have been mapped in different populations comparative genome analyses were performed. Partial alignments of linkage groups of our reference population with those of other published maps have been obtained. 9 of the 12 LGs of the reference map could be assigned to P. taeda linkage groups as well as to 7 Pinus elliottii, 7 P. pinaster (INRA) and 6 Pinus radiata (New Zealand) linkage groups. Moreover, several linkage groups of the P. radiata partner populations could be associated with linkage groups of the reference map and other maps. - QTL analysis for several characters related to wood quality (alpha cellulose, lignin content, pulp yield, extractives content, CIE, wood densities), growth characteristics (height, diameter, spring growth, flushing, branching) and physiological traits (vegetative and generative bud formation, flowering) were performed in reference and partner populations and QTLs were detected for most characters. In the reference population between 3 and 8 QTLs were detected for the characters under study. Individual QTLs explained between 5 and 19% of the total variation and their cumulative effects up to 58% (diameter). In several occasions pleiotropic effects of probably identical QTLs influencing different characters were observed (alpha cellulose, lignin and total extracts or height and diameter). This is also reflected in the partial trait correlations which were observed. Some QTLs for height and diameter measured in two different years remained stable over years. - In the partner populations QTLs were detected for height in P. radiata, P sylvestris and Pseudotsuga, for diameter and spring growth in P. radiata and for flushing in Pseudotsuga. Some traits segregated as controlled by major genes and could be mapped.

These include vegetative and generative bud formation and tree form in P. radiata, cone production in Picea and polyciclism in Pseudotsuga. - The analysis of several common characters allowed also to perform comparative QTL studies in reference, partner and other published mapping populations. The lack of cross-referenced markers hampered the comparison of QTLs. Nevertheless, certain common structures were detected for height QTLs in different conifer species. -A total of 15 CAP markers for QTLs for wood quality and growth characteristics have been developed by the consortium. In several cases specific allele markers were significantly informative for height, diameter, rectitude and for lignin, cellulos or pulp contents of P. pinaster breeding material. Such markers can be applied conveniently for marker assisted selection of unknown breeding material in this species.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

INSTITUTO VASCO DE INVESTIGACION Y DESARROLLO AGRARIO - NEIKER A.B.
Address
Granja Modelo De Arkaute S/n
01080 Vitoria (Alava)
Spain

Participants (2)

FEDERAL RESEARCH CENTRE FOR FORESTRY AND FOREST PRODUCTS
Germany
Address
Sieker Landstraße 2
22927 Grosshansdorf
UNIVERSITE HENRI POINCARE NANCY 1
France
Address

54501 Vandoeuvre-les-nancy