Resistance of IFVCNS inbred lines to race F with origin from Spain

Broomrape (Orobanche cumana) is one of the most important constraints for sunflower croping. Parasite populations are segregating on virulence criterion and different races are described. Breeding efforts directed for development of resistant genotypes face challenges such as genetically diverse broomrape populations and broomrape of different virulence. One strategy to minimize the impact of broomrape virulence variability in breeding for resistance is to test sunflower genotypes resistance with broomrape with different origins. In this study, a selection of 24 IFVCNS inbred lines based on resistance to dominant broomrape populations in Serbia was tested to broomrape race F, collected in a sunflower field of Andalusia region in Spain. Six-week greenhouse pot experiments were conducted in CSIC, Spain. The line B117, used as susceptible control, had broomrape on all tested plants. For 13 genotypes no broomrape was present on roots, 10 genotypes had broomrape attached on part of tested plants, and broomrape incidence on one genotype was 100%. Inbred lines were analyzed on the basis of genetic background and importance in breeding. In the group of AB-OR lines, with origins from Helianthus divaricarus, 7 out of 9 lines were completely resistant. Inbred line HA-267, with a single recessive mode of resistance inheritance, was confirmed resistant. Inbred lines, RUB-3 and SOL-SU-26 were also completely resistant to broomrape. The results indicate the importance of using different broomrape populations and conducting multi-location experiments to enhance the breeding process together with using various sources of resistance. Selection of resistance genotypes will be further tested for their resistance to broomrape populations and resilience to adverse enviromental conditions.

This work is supported by the European Commission through projects CROPINNO, grant number 101059784, the Science Fund of the Republic of Serbia, through IDEAS project “Creating climate smart sunflower for future challenges” (SMARTSUN), grant number 7732457, and by the Ministry of Science, Technological Development and Innovation of Republic of Serbia, grant number 451-03-66/2024-03/20032, and by the Centre of Excellence for Innovations in Breeding of Climate- Resilient Crops – Climate Crop, Institute of Field and Vegetable Crops, Novi Sad, Serbia.

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