Diversity and population genetic structure of Venturia inaequalis on different apple cultivars in the north of Iran

Document Type : Research Paper

Authors

1 Assistant Professor, Department of Entomology and Plant Pathology, College of Aburaihan, University of Tehran, Tehran, 33916-53755, Iran and Ph. D. Candidate, Department of Plant Protection, Faculty of Agricultural Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Karaj, 31587-77871, Iran

2 Associate Professor, Department of Plant Protection, Faculty of Agricultural Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Karaj, 31587-77871, Iran

3 Professor, Department of Plant Protection, Faculty of Agricultural Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Karaj, 31587-77871, Iran

4 Professor, Department of Biotechnology, Faculty of Agricultural Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran

Abstract

Apple scab disease caused by Venturia inaequalis is the most important economic disease worldwide where the apple is grown and causes annual epidemics. It reduces the quality and quantity of the yields in different regions of Iran. In this study, diversity and population genetic structure of V. inaequalis were surveyed on different apple cultivars using 18 microsatellite markers. 51 isolates were obtained from infected leaf and fruit specimens from wild apple, Iranian endemic and commercial apples from Northern provinces of Iran (Mazandaran, Golestan and Guilan). 28 SSR primers were used to investigate the genetic diversity of this pathogen. Among them, 18 primers showed polymorphism between isolates and populations. AMOVA analyses revealed that 97% of the variation was distributed among individuals within populations, and 3% was attributable to the differences among populations. Gene diversity indexes including Nei’s gene diversity, Shannon index and allele numbers in every population showed that diversity within the population on endemic cultivars is more than the diversity in the population of wild and commercial cultivars. Also, the population of commercial cultivars has more diversity in comparison with the wild population. High genetic diversity within the populations is caused by annual sexual reproduction, gene flow between populations and probably the existence of this fungus for a long time in this region.

Keywords


  1. Ashkan, S. M. (2011). A textbook of fruit crops diseases in Iran. Aeeizh, 472 pp, Tehran, Iran.
    (in Farsi)
  2. Boehm, E. W. A., Freeman, S., Shabi, E. & Michailides, T. J. (2003). Microsatellite primers indicate the presence of asexual populations of Venturia inaequalis in coastal Israeli apple orchards. Phytoparasitica, 31(3), 236-251.
  3. Bruce, A., McDonald, B. A. & Linde, C. (2002). Pathogen population genetics, evolutionary potential, and durable resistance. Annual Review of Phytopathology, 40, 349-79. 
  4. Clark, M. D. (2014). Characterizing the host response and genetic control of resistance in ''Honeycrisp'' to apple scab (Venturia inaequalis). Ph. D. dissertation. University of Minnesota. 228 PP.
  5. Ershad, D. (2009). Fungi of Iran. Iranian Research Institute of Plant Protection, 531 pp, Tehran, Iran. (in Farsi)
  6. Guerin, F., Franck, P., Loiseau, A., Devaux, M. & Le Cam, B. (2004). Isolation of 21 new polymorphic microsatellite loci in the phytopathogenic fungus Venturia inaequalis. Molecular Ecology Notes, 4 (2), 268-270.
  7. Guérin, F., Gladieux, P. & Le Cam, B. (2007). Origin and colonization history of newly virulent strains of the phytopathogenic fungus Venturia inaequalis. Fungal Genetics and Biology, 44, 284-292.
  8. Gharghani, A., Zamani, Z., Talaie, A., Oraguzie, N. C., Fatahi, R., Hajnajari, H., Wiedow, C. & Gardiner, S. E. (2009). Genetic identity and relationships of Iranian apple (Malus domestica Borkh.) cultivars and landraces, wild Malus species and representative old apple cultivars based on simple sequence repeat (SSR) marker analysis. Genetic Resources and Crop Evolution, 56, 829-842.
  9. Gladieux, P., Zhang, X.-G., Afoufa-Bastien, D., Valdebenito Sanhueza, R.-M., Sbaghi, M., et al. (2008). On the origin and spread of the scab disease of apple: out of central Asia. PLoS ONE 3(1), e1455. doi:10.1371/journal.pone.0001455.
  10. McDonald, B. A. (1997). The population genetics of fungi: tools and techniques. Phytopathology, 87 (4), 448-453.
  11. McDonald, B. A. & Linde, C. (2002). Pathogen population genetics, evolutionary potential, and durable resistance. Annual Review of Phytopathology, 40, 349-79.
  12. Nei, M. (1987). Molecular evolutionary genetics. (1st ed.). New York, USA: Columbia University Press.
  13. Padder, B. A., Shah, M. D., Ahmad, M., Sofi, T. A., Ahanger, F. A. & Hamid, A. (2011). Genetic differentiation among populations of Venturia inaequalis in Kashmir: A north-western state of India. Asian Journal of Plant Pathology, 5, 75-83.
  14. Passey, T. A. J., Shaw, M. W. & Xu, X.-M. (2015). Differentiation in populations of the apple scab fungus Venturia inaequalis on cultivars in a mixed orchard remain over time. Plant Pathology, Doi: 10.1111/ppa.12492.
  15. Peakall, R. & Smous, P. E. (2012). GenALex 6.5: genetic analysis in Excel. Population genetic software for teaching and research-an update. Bioinformatics, 28, 2537-2539.
  16. Ruszkiewicz-Michalska, M. & Połeć, E. (2006). The genus Fusicladium (Hyphomycetes) inPoland. Acta Mycologica, 41 (2), 285-298.
  17. Stukenbrock, E. H. & McDonald, B. A. (2008). The origins of plant pathogens in agro-ecosystems. Annual Review of Phytopathology, 46, 75-100.
  18. Schubert, K., Ritschel, A. & Braun, U. (2003). A monograph of Fusicladium s. lat. (Hyphomycetes). Schlechtendalia, 9, 1-132.
  19. Tenzer, I., Degli Ivanissevich, S., Morgante, M. & Gessler, C. (1999). Identification of microsatellite markers and their application to population genetics of Venturia inaequalis. Phytopathology, 89 (9), 748-753.
  20. Xu, X., Yang, Y., Thakur, V., Roberts, A. & Barbara, D. (2008). Population variation of apple scab (Venturia inaequalis) isolates from Asia and Europe. Plant Disease, 92, 247-252.
  21. Xu, X., Roberts, T., Barbara, D., Harvey, N. G., Gao, L. & Sargent, D. J. (2009). A genetic linkage map of Venturia inaequalis, the causal agent of apple scab. BMC Research Notes, 2, 163. Doi: 10.1186/1756-0500-2-163.
  22. Yeh, F. C., Yang, R. C. & Boyle T. (1999). POPGENE version 1.31., Microsoft Window-based Freeware for population genetic analysis. University of Alberta, Edmonton, Canada.
  23. Zhang, L. (2010). Genetic diversity and temporal dynamics of Venturia inaequalis populations following two apple scab epidemics in Pennsylvania. Master thesis, The Pennsylvania State University, The Graduate School College of Agricultural Sciences. Available: https://etda.libraries.psu.edu/catalog/11414.