Genetic populations of tree crops adequate for linkage mapping and other genetic analyses are difficult to obtain and expensive to maintain. This is because of:

• Their long seed-to-seed or seed-to-adult periods, and


• The large size of the plants.

Their advantage is that individuals live for many years if appropriately maintained, allowing for the same plant to be phenotyped and genotyped with different objectives and at different life stages. Such plants can also be easily reproduced asexually by grafting or cuttings.

Populations of other Rosaceae, such as strawberry, raspberry or rose, have smaller sizes and shorter life cycles. They can also be maintained for long periods of time and be asexually reproduced. They are also valuable resources, interesting for the Rosaceae community and of expensive maintenance.

The objective of RosPOP is to facilitate access to materials and information associated with these Rosaceae populations for research groups other than those who originally created and maintain them.

This access will require an agreement amongst members of the consortium. The agreement would include the signature (or any other way to formalise the involvement of different partners) of a document that would specify the characteristics of the agreement and the populations that each partner would include in the consortium.

The agreement should have the simplest possible format. It should be a good will agreement, so that commitments that imply some degree of involvement for the owner of the populations (particularly in the supply of materials, e.g., DNA, leaves, pollen, graftwood) should be done if possible. However, access to information and materials when this does not imply any (or very little) additional effort should be always possible.

This document should include the following commitments with respect to these populations:

• Access to plant materials (any parts of the plant including graftwood)


• Access to DNA, RNA, or other genetic resources


• Possibility of propagation of the whole population or individuals of that population in the fields of other members


• Access to the populations themselves by other groups for the purpose of collecting materials or phenotypic data


• Access to all raw and analysed genotypic data (including any kind of sequence information, markers, etc.) from published studies of the individuals


• Access to all raw and analysed phenotypic data of published studies of the individuals

The owner of all individuals of each population will be the organisation that has produced and supplied it for the objective of commercializing any of these individuals in a cultivated variety.

The use of the materials of these populations should not imply automatically any charge for their users (economic costs, participation in publications, etc.).

One ideal place for maintaining the information referred to in points e) and f) would be the GDR (Genome database for Rosaceae, http://www.rosaceae.org). This information consists essentially of the files with marker and phenotypic data of all kinds for the individuals of these populations. Access to these data could be restricted to the members of the RosPOP.

The ideal population to be included in RosPOP would contain a sufficient number of anchor markers with the TxE Prunus reference map (or the equivalent for other genera) to make a one-to-one correspondence of linkage groups. This does not discard the possibility that other populations lacking such anchor markers could be included.

Expected benefits of RosPOP are:

• Broadening of the current capabilities of different groups for genetic analyses of characters of interest by having access to additional phenotyped and genotyped      plant materials.


• Maximised use of current Rosaceae mapping populations. Although this is not a central objective of the RosPOP, it may allow replication of certain populations      at different sites, for phenotypic studies in different locations, ease of access to plant material, or conservation of important material.


• Further justification for considering these populations as strategic genetic resources with the need for long-term preservation.


• Facilitation in the interchange of DNA, markers, and chemicals implicated in marker development (e.g., primers and probes), resulting in faster, more effective,      or less costly research.


• Encouragement of the development of a bin set for each mapping population, to facilitate the assessment of marker polymorphism and map location

For Prunus, presently the genus with the most developed genetic mapping resources in Rosaceae, one possible action of RosPOP would be to place on the TxE reference map as many transferable PCR-based markers as possible. For this objective:

• DNA materials from the parents of TxE and the best characterised populations (currently a total of 8-10 populations) should be distributed to each member of      RosPOP.


• Markers of any kind (preferentially SSRs or those based on expressed sequences) developed by Ros POP members but not already placed on the TxE map (due      to monomorphism or not previously studied in this population) would be tested across the parents of each of these populations, and information on polymorphism      transferred to population owners and to the scientific community (via the GDR).


• New markers could be placed on the reference map in different ways:


• Using the bin set of TxE when the marker is polymorphic in TxE


• Using a bin set or all progeny of other populations when the marker is monomorphic in TxE, then inferring reference map position by comparative mapping
• DNA and concomitant information from the bin sets of TxE or other populations should be available to the members of the RosPOP that request them


• A list that is as complete as possible of markers (SSR and EST-derived) already tested in TxE and in any of the other populations could be compiled for the      community, with descriptions of test outcomes (e.g., amplification success, polymorphism, map position).


• The information obtained would be transferred to the GDR for general access