CHARACTERISATION OF LATVIA FRUIT CROP GENETIC RESOURCES BY APPLICATION OF MOLECULAR GENETICS METHODS

A large diversity of fruit crop accessions is maintained at the Latvia State Institute of Fruit- Growing, which consists of modern cultivars, landraces and selections from local breeding programmes, as well as germplasm that has resulted from scientific exchange and co-operation with other institutes. Presently, the germplasm collection comprises 2509 accessions of 17 fruit crops; 676 accessions are designated as national genetic resources. Conservation of germplasm itself has little value without characterisation and further utilisation of the stored plant material. To intensify these activities, DNA-based technologies have been implemented in the characterisation of germplasm. Two main groups of molecular markers have been utilised: non-specific markers and gene-specific (functional) markers, subsequently applicable for Marker Assisted Selection (MAS). Genotyping protocols based on SSR, RAPD and Methylation-sensitive amplification polymorphism (MSAP) markers have been developed for twelve fruit crops for use in plant material identification, True-to-Type verification and evaluation of genetic diversity and internal collection structure. In total, 790 accessions have been genotyped using any of the mentioned markers. These markers have been harmonised with the European cooperative programme for plant genetic resources working group (ECPGR WG) recommended sets to ensure international data exchange. Gene specific molecular markers have been applied to apple and pear (resistance to scab), strawberry (resistance to Gnomonia fragariae), sweet cherries and plums (self-incompatibility).