Vegetative compatibility of Sclerotinia sclerotiorum (Lib.) de Bary strains isolated in Hungary

Similarly to other Ascomycetes, Sclerotinia sclerotiorum isolates of the same vegetative compatibility groups are able to form heterokaryons. However, little information exists on vegetative compatibility groups (VCGs) within this species. The aim of our study was to examine vegetative compatibility among 29 Hungarian field isolates of S. sclerotiorum. Lines resistant to one of 2 different fungicides (procymidone and tebuconazole) were used to test heterokaryon formation. Thirteen VCGs have been identified, 6 of them containing more than one strains. Twenty-one strains were compatible with at least one another. Strains isolated from different locations never belonged to the same VCG. Results suggest that there are a great number of VCGs in S. sclerotiorum

Susceptibility of sour cherry cultivars to isolates of Monilia laxa (Ehrenbergh) Saccardo et Voglino

In this study, the susceptibility of 7 commercially important sour cherry cultivars to Monilinia laxa was studied. Artificial inoculation was made with M. laxa isolates, which were isolated from different woody plants. Artificial inoculation was prepared in the laboratory and in the field. In laboratory, flowers of sour cherries while in the field, the two-year old twigs were inoculated in 2006 and 2007. According to results of stigmata inoculation, there were infection ability differences among the isolates originated from five different stone fruit host. Cultivars could be sorted into two susceptibility groups. In the field, twig inoculation in 2007 was made at blossom period and in 2007 at harvest. Seven sour cherry cultivars were inoculated with 8-day-old mycelial culture of M. laxa originated from sour cherry and almond. The agressivity and pathogenicity of the two isolates were measured by the degree of floem death: Results showed that year and phenological stage considerably influenced the degree of symptoms caused by the fungus. After artificial inoculation, tissue death progression was studied by fluorescent microscope. According to results, sour cherry cultivars were sorted into disease susceptibility groups. Susceptibility orders were identical to results on stigmata inoculation

Susceptibility of sour cherry cultivars to isolates of Monilia laxa (Ehrenbergh) Saccardo et Voglino

In this study, the susceptibility of 7 commercially important sour cherry cultivars to Monilinia laxa was studied. Artificial inoculation was made with M. laxa isolates, which were isolated from different woody plants. Artificial inoculation was prepared in the laboratory and in the field. In laboratory, flowers of sour cherries while in the field, the two-year old twigs were inoculated in 2006 and 2007. According to results of stigmata inoculation, there were infection ability differences among the isolates originated from five different stone fruit host. Cultivars could be sorted into two susceptibility groups. In the field, twig inoculation in 2007 was made at blossom period and in 2007 at harvest. Seven sour cherry cultivars were inoculated with 8-day-old mycelial culture of M. laxa originated from sour cherry and almond. The agressivity and pathogenicity of the two isolates were measured by the degree of floem death: Results showed that year and phenological stage considerably influenced the degree of symptoms caused by the fungus. After artificial inoculation, tissue death progression was studied by fluorescent microscope. According to results, sour cherry cultivars were sorted into disease susceptibility groups. Susceptibility orders were identical to results on stigmata inoculation

Mycelial compatibility of Sclerotinia sclerotiorum strains of different areas

Mycelial compatibility of 47 strains of Sclerotinia sclerotiorum, a plant pathogenic fungus was investigated. Since fungal strains of the same mycelial compatibility group (MCG) are genetically uniform, or highly similar, the number of MCGs reflects the genetic variability within the species. Pairings were carried out on tomato agar, and scored compatible or incompatible depending on the reaction between the strains. Strains of the same origin often gave incompatible reactions (barrage zone between their colonies), confirming the existance of several MCGs at the some place. Same MCGs were found even at distant locations, reflecting that some of the genotypes are widespread in the country

In situ characterization of some sweet and sour cherry autochthonous genotypes in West Serbia region

Autochthonous cherry genotypes in the Republic of Serbia can potentially provide a rich and useful genetic variability, especially for ripening time, fruit quality and resistance to diseases. Fruit Research Institute, Cacak has a long tradition in collecting new sweet and sour cherry genotypes, as well as in evaluation and utilization of autochthonous material with good agronomic properties. This study was carried out to determine the main biological properties of six sweet cherry (Prunus avium L.) genotypes ('GT-1', 'GT-2', 'GT-3', 'GT-4', 'GT-5', 'GT-6'), and eight sour cherry (Prunus cerasus L.) genotypes ('GV-1', 'GV-2', 'GV-3', 'GV-6', 'GV-7', 'GV-10', 'GV-12', 'GV-13'). Over two years (2016-2017), the following properties of in situ cherry genotypes in West Serbia region were investigated: ripening time, pomological properties (morphometric and chemical), and field resistance to causal agents of cherry diseases - cherry leaf spot (Blumeriella jaapii (Rehm.) v. Arx.), brown rot (Monilinia spp.) and cherry fruit fly (Rhagoletis cerasi L.). The highest average fruit weight among investigated sweet and sour cherry genotypes was found in 'GT-5' (11.00 g) and 'GV-13' (7.64 g), respectively. The highest soluble solids content was found in 'GT-1' and 'GT-3' (16.20%) and 'GV-7' (17.30%), respectively. In terms of field resistance to pathogens, 'GT-1', 'GV-6' and 'GV-10' showed the best performance. To avoid the loss of this material, it is necessary to collect and characterize these genotypes to allow their conservation in germplasm collections, and to provide preconditions for a successful cherry breeding work