Sweet pepper breeding against bacterial spot (Xanthomonas euvesicatoria) in Serbia

Abstract

Bacterial spot of pepper (BS) caused by Xanthomonas euvesicatoria is one of the most important pepper diseases in Serbia. Growing of resistant pepper genotypes is the most efficient way of BS control. The study was started in 2013, when eight pepper varieties from the Institute of Field and Vegetable Crops, Novi Sad (IFVCNS), Cal wonder and isogenic line from Early Cal wonder (ECW-20R) were inoculated with X. euvesicatoria strain P8 in the field conditions. Intensity of infection was evaluated according to the Horsfall-Barratt (HB) scale. Nonparametric Kruskal-Wallis test was used for statistical analysis. All tested varieties were susceptible, except ECW-20R. In the same year, several IFVCNS pepper varieties were crossed with ECW-20R and also with line 30. After crossing 3 hybrids were sown in a greenhouse in October 2013 to obtain F2 generation. Those F2 transplants with resistant parents and Cal Wonder were planted 2014 in open field and inoculated. In the other field, IFVCNS varieties (Amfora, Una, Matica), line 30, ECW-20R and their 6 hybrids were evaluated under natural infection. Hybrids showed a significant resistance in relation to susceptible parents, except combination Matica x ECW-20R. Seeds of selected plants (F2 and F1 generation) from those two fields were sown for transplants producing in 2015 in order to obtain F3 and F2 generation. Transplants were inoculated in a greenhouse. Healthy plants were transplanted in the open field and after three months evaluated again. Progenies from ECW-20R were more resistant than progenies from line 30.