Sweet Cherry Crossing Techniques

Transcription

1 STSM Scientific Report COST STSM Reference Number: COST-STSM-FA Reference Code: COST-STSM-: ECOST-STSM-FA Sweet Cherry Crossing Techniques Short term scientific mission (STSM) supported by and serving aims of: COST action FA1104: Sustainable production of high-quality cherries for the European market Ms Marzena Lipska East Malling Research East Malling(UK) Dr José Quero Garcia Institut National de la Recherche Agronomique Bordeaux(FR)

2 Purpose of the STSM: The main objective of my STSM was to understand and exchange the knowledge to develop better techniques with improved accuracy and efficiency for sweet cherry crossings and overall understanding of breeding programme. In addition of this, the aim was to attend the EUBerry meeting that allowed updating the knowledge on soft fruit area. Description of work carried out: Several meetings with the team involved in the breeding programme have been held and allowed me to learn that the most efficient technique for crossing is controlled pollination where bumble bees are used. This task is made in the especially built tunnel with four compartments and covered with the insect proof mesh. Each compartment has its own corridor with double door that helps to control bumble bees escape, any other insects to come in and can be used as potting up, storage, etc. space, which might be useful in the high health production. With well-designed tree planting for the crossings, as it is used with the plants in the pots, it is a really efficient and with a high rate success technique. Transferring the pots is done by human power but plan for transport is to develop new technique and resolve this issue. At EMR in 2013 a prototype cage has been built inside of the tunnel, used mainly for pollination purposes, with medium results but it was used for inter-specific hybridisation for which pollinatin is more difficult and one of the bumble bee hives had poor activity at the beginning of the season. Because of too small size and in rush built construction, in 2014 a new tunnel is going to be built which will allow to increase the size and separate it into two compartments. Bumble bee method is used as well in the field at INRA where the planted tree is covered with mesh cage where pollinator tree and the bumble bee hive is moved into. It is a good practise, efficient and in semi natural environment.

3 Another technique which is highly used by the breeders is hand pollination. Of course it is not as efficient as the bumble bee method but necessary as not all cultivars used in the purpose of breeding programmes are flowering at the same time and it is difficult to have a large set of parental genotypes in pots, so emasculation, with different tools to use, and finger/ brush pollination with earlier collected pollen, is necessary. Tool used at INRA Tool used at EMR One of the main aims of the research in Sweet Cherry breeding at INRA is resistance to fruit cracking and lots of experiments and field trials have been done, such as using a polytunnel with sprinkle overhead irrigation system in 2008 and 2009 for the progeny of Regina x Lapins cross, or Christensen method in 2009, where fruits where soaked/immersed in the distilled water for 2, 4 and 6 hours and the number of cracked fruits counted. Although these two artificial methods gave good results, the best was trial on the field. The most interesting QTL results were found for apical cracking. Another important work carried out at INRA is modelling for adaptation of cherry cultivation to climate change by using genotype characteristics, climate conditions, phenotyping data, RNAseq, epigenetics and PLS regression.

4 In 2010 from the crossing programme 3000 open and controlled pollination seedlings have been raised where 1300 are from Regina x Garnet cross and 600 F 2 progeny of self-fertile Lapins brought 2000 seedlings from open and controlled crosses. In 2012 only controlled pollination seedlings were grown in amount of 650 seeds, same happened in 2013 with 500 seeds. Seeds are stratified by sterilizing stone in calcium hypochlorite then cracked and without shell moved into vermiculate and bagged. The entire bag is moved into coldstore and stored for minimum 2 months. Any germinated seeds are removed and potted up in P9 disposable pots containing light compost for further growth in the glasshouse environment. When reaching good growth and vigour, they are planted in the field on their own roots for future evaluation. Remained not germinated seeds are kept in vermiculate for later germination. One of the techniques to raise the seedlings is In Vitro Embryo Rescue which is commonly used for the early ripening cultivars. At INRA sterilized stones are cracked and seeds are moved into tubes with standard media. Racks with tubes are placed in the coldstore then moved into the growth room for two weeks when germination starts. After the germinated plantlets have reached about 10 cm height (in general after two week s period) they are moved into the light compost to the glasshouse and covered with a transparent plastic cup. Where plants reach 5-6 centimetres growth, cups are cut on the top to reduce humidity from transpiration, and when they have grown for a little bit more, then the entire cup is removed. At EMR in 2013 we have been carried out in vitro propagation trial with standard media but including growth hormones. In 2014 a new protocol combining different ideas will be developed.

5 INRA EMR Comments: - During the STSM I had the opportunity to gain further knowledge about Sweet Cherry breeding techniques such as pollination and in vitro propagation that will allow me to apply and develop methods used at EMR. - Working with such a knowledge group at INRA gave me better overall understanding of Cherry breeding. - I am sure that future collaboration and further knowledge exchange will bring new developments in the Sweet Cherry - I have had the opportunity as well to update my expertise in soft fruit area by attending EUBerry school/meeting. I would like to thank to Dr José Quero Garcia for his time, knowledge and fantastic hospitality, same for whole Cherry group at INRA for their smiles, help and making my time enjoyable. East Malling, 25 th April 2014 Marzena Lipska Confirmation by the institution of the successful execution of the STSM: Date: Signature: