Physiological specialization of Septoria tritici Rob. and Desm.
Sanin S.S., Sanina A.A., Paholkova E.V.
All-Russia Research Institute of Phytopathology, 143050, B.Vyazemy, Moscow region, Russia
Knowledge of the physiological specialization of the pathogen is one of the preconditions of successful realization of programs on selection of plants on diseases resistance. The objective of this study was to determine the physiological specialization of Septoria tritici in two populations in the Central and North Caucasian regions of the European part of Russia. The wheat cultivars with different reactions to the pathogen were selected on the basis of previous research. Twenty-one isolates of S. tritici, originating from different regions of Russia and more than 300 winter and spring wheat cultivars were used in experiments. Testing the interaction “cultivar x isolate” was carried out at the seedling stage using two parameters: the infection degree of the two primary leaves area (%) and intensity of the sporulation of the pathogen in vivo. By these indexes S. tritici isolates were divided into three pathogenicity groups (low, moderate and high). Similarly, reactions of wheat cultivars to the pathogen were classified into resistant (R), intermediate (M) and susceptible (S) types. Using the method of complete connection of the cluster analysis, six cultivars with specific reactions with individual isolates of the pathogen were preliminiarily selected: Harkovskaya 46, Mironovskaya 808, Saratovskaya 29, Moskovskaya 35, Bezostaya 1 and Odesskaya 51. Based on isolate pathogenicity to the differential cultivars and morphological type of colonies on nutrient medium (agarized potato-glucose), 43 races of S. tritici were identified in the Central region and 48 races in the North Caucasian region. The racial compositions of S. tritici populations in investigated regions were different. Only three races were detected in both regions. More races that are virulent on more than half (4) of the differential cultivars were detected in the population of North-Caucasian region (about 17%) than in the Central region (9%). Essential distinctions on isolate morphotypes between populations were not observed. In both populations isolates of yeast-like and mixed colony type were dominant. The work was carried out under the project of International Science Technology Centre.
Application of RFLP for genetic characterization of Colletotrichum pathogens of lupins.
Katarzyna Pieczul, Maria Rataj-Guranowska
Collection of Plant Pathogens, Institute of Plant Protection, Miczurina 20, Poznań, Poland
Anthracnose caused by Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. is one of the most important disease of lupins in Poland. The pathogen infects all species commonly cultivated - Lupinus luteus (L.), L. albus (L.), L. angustifolius (L.) and L. polyphyllus (L.), causing brown lesions and typical twisting steams or petioles. Population of C. gloeosporioides from lupins based on RFLP and RAPD analysis was divided into two major, distinct groups - COL 1 and COL 2. The majority of isolates were classified as COL 2 and were found throughout the world including Europe. On the basis of the nucleotide sequence of the rDNA internally transcribed spacer (ITS), the lupin anthracnose casual pathogen was identified as C. acutatum by some authors. Fifty-three isolates used in this study were obtained in 1995 – 2003 years, from naturally infected lupin plants, collected from different regions of Poland. Colletotrichum sp. was also isolated from other plants - Pisum sativum L. subsp. arvense, Orniothopus sativus Brot. and Lycopersicon esculentum Mill. Single-spore cultures were prepared from each isolate. All isolates were included into Collection of Plant Pathogens Institute of Plant Protection in Poznań. Restriction fragment length polymorphism (RFLP) was used to assess genetic variations among isolates. Genomic DNA was extracted from fresh mycelium, using DNeasy Plant Mini Kit Qiagen according to manufacturer’s instructions. Universal primers ITS 1 and ITS 4 were used for PCR amplification of 5,8S rDNA and internal transcribed spacers as previously described. Amplificated product of approximately 560 base pairs was digested with 11 restriction enzymes, separated on agarose gel and compared with RFLP patterns of isolates which belong to COL 1 and COL 2. All Polish lupins isolates have the same RFLP patterns and correspond to the world dominating COL 2 group patterns. Surprisingly isolates from Pisum sativum L. subsp. arvense and Lycopersicon esculentum were included also into this group. The second, major group COL 1 was not detected in Poland. Two isolates from Orniothopus sativus were in the same RFLP group, distinct from RFLP patterns for COL 1 and COL 2 groups.
Oak powdery mildew: morphological and genetic identification of several isolates collected in south part of Czech Republic.
Dr. Miloslava Kavkova*, Dr. Vladislav Curn**, Barbora Kubátová** and Veronika Heřmanová**
*University of South Bohemia in České Budějovice, Faculty of Biology, Dept. Of Botany České budějovice CZ-37005, Czech Republic e-mail:
** University of South Bohemia in České Budějovice, Faculty of Agriculture, Biotechnological Centre, Studentská 13, České Budějovice CZ-37005, Czech Republic
The oaks, Quercus petraea and Quercus robur are two major forest broadleaf species in Central Europe. At the moment, oaks are the most endangered genus in Czech Republic after elms because of environmental conditions, complex of disease including tracheomycoses, oak powdery mildew and improper reproductive material. In the past, the mixture forests were substituted by spruce monocultures that caused many of