Introduction of certification program in production of plum planting material

Abstract

Certification program for the production of fruit planting material has not been fully established in the Republic of Serbia. Despite this fact, Fruit Research Institute, Čačak has initiated the introduction of certification into the production of plum planting material of cultivars developed at the Institute. The main goal is to establish plum mother plantations with basic material satisfying the EPPO recommendations and national certification standards.

Propagated material from pomologically selected trees in commercial and experimental orchards was collected and grafted onto virus-free Myrobalan rootstock. Candidate clones are kept in screen house which ensure absence of infection. Fifteen plum (Prunus domestica) cultivars are included in this study: ‘Čačanska Lepotica’, ‘Čačanska Rodna’, ‘Čačanska Najbolja’, ‘Čačanska Rana’, ‘Valjevka’, ‘Valerija’, ‘Čačanski Šećer’, ‘Jelica’, ‘Timočanka’, ‘Boranka’, ‘Mildora’, ‘Krina’, ‘Pozna Plava’, ‘Požegača’, ‘Stanley’, and perspective hybrid 14/21.

All tests were done according to the EPPO recommendations. Selected clones were tested on woody indicators Prunus tomentosa, P. persica and P. serrulata cv. Shirofugen. ELISA test was duly performed for the detection of the following viruses: Plum pox virus, Prune dwarf virus, Prunus necrotic ringspot virus, Apple chlorotic leaf spot virus, Apple mosaic virus and Myrobalan latent ringspot virus. To increase the sensitivity of Plum pox virus detection, IC-RTPCR was used. The material was also tested for the presence of ‘Candidatus Phytoplasma prunorum’ by nested-PCR method.

The presence of viruses was found in 8 plants. ELISA test revealed that four plants of cv. ‘Jelica’ were found to be positive on the presence of Apple chlorotic leaf spot virus. Latent infection with Plum pox virus was detected by IC-RTPCR in 4 candidate clones (1 plant of each of cvs ‘Valerija’, ‘Čačanska Rodna’, ‘Čačanska Lepotica’ and ‘Požegača’). The rest of the material was free of all other viruses. The infection with ‘Candidatus Phytoplasma prunorum’ was not evidenced in any of the tested plants.

Keywords: certification, plum, viruses, phytoplasmas