The Detection of Crown Gall Disease in Kahramanmaraş and Surrounding Provinces

Abstract

Aims: The aim of the study is to isolate the bacterial agent causing crown gall disease in Kahramanmaraş and its surrounding provinces, determine its prevalence in the region, and conduct its identification. 
 Material and methods: Between June and September of 2017-2019, strains obtained from the shoots and galls of vines showing symptoms of galls in vineyards in Kahramanmaraş, Adıyaman, Kilis, Gaziantep, and Şanlıurfa provinces were subjected to pathogenicity tests, classical, molecular, and MALDI-TOF MS identification.
 Results and Discussion: In this study, the prevalence of crown gall disease in 46 vineyards showing disease symptoms was determined as follows: Kahramanmaraş 76.47%, Adıyaman 75%, Gaziantep 50%, Kilis 33.33%, and Şanlıurfa 20%. From the 46 contaminated vineyards in the study area, 24 pathogenic of R. vitis strains were obtained. In the pathogenicity test conducted with R. vitis strains on the Hatun Parmağı grape variety under greenhouse conditions, the most virulent strains were determined based on the weights of the galls formed, and they were identified as CU52-3/2, CU39-11/5, and CU39-8/1. According to classical tests, 13 strains showed 100% similarity to R. vitis, while molecular characterization with R. vitis-specific primers revealed that 17 strains had the virA gene, 13 strains had the pehA gene, 10 strsains had the virF gene, and 6 strains had the octopine-type plasmid. Ten strains, representing the sample, were identicated as R. vitis through MALDI-TOF MS analysis. This study revealed the impact of pathogenic strains with different virulences on the same grape variety. In line with this, of control methods against highly virulent bacterial agents in reducing losses in plants can be investigated for their applicability in field and orchard areas in subsequent studies.
 Conclusions: Research on different grape varieties is essential to develop varieties that are resistant or tolerant to R. vitis, the pathogen causing this prevalent disease in Turkish viticulture.