Analysis of strawberry genetic collection (Fragaria L.) for Rca2 and Rpfl genes with molecular markers

Strawberry (Fragaria x ananassa Duch.) varieties are susceptible to many fungal diseases. Identification of forms, carrying resistance genes, is an important stage in breeding programs leading to resistant varieties. The use of molecular markers allows to determine with high reliability the presence of the necessary genes in the genome and to identify promising forms. Some of the common strawberry's diseases, causing significant damage to strawberry plantations, are anthracnose (Colletotrichum acutatum Simmonds) and red stele root rot (Phytophthora fragariae var. fragariae Hickman). Dominant Rca2 gene is involved in monogenic resistance to C. acutatum pathogenicity group 2. Rpf1, Rpf2, Rpf3 genes are determined in monogenic resistance to red stele root rot. The purpose of this study was molecular genetic testing genotypes of genus Fragaria L. to identify carriers of Rca2 allele anthracnose resistance and Rpf1 allele red stele root rot resistance. The objects of study were the wild species of the genus Fragaria L. and strawberry varieties (Fragaria x ananassa Duch.) of different ecological and geographic origin. To assess allelic state Rca2 anthracnose resistance gene the dominant SCAR marker STS-Rca2_240 was used, was linked to the resistance gene Rca2 with a genetic distance of 2.8 cM. Rpf1 gene red stele root rot resistance was identified with the dominant SCAR marker R1A, was linked to the resistance gene Rpf1 with a genetic distance of 3.0 cM. The resistant allele of the marker STS-Rca2_240 was identified in the Laetitia variety (Rca2Rca2 or Rca2rca2 genotype), which allows us to recommend it as a promising source in breeding for anthracnose resistance. The other studied forms have homozygous recessive state of the marker STS-Rca2_240 (putative genotype rca2rca2). The resistant allele of the marker SCAR-R1A in the varieties and wild species of strawberry under study is absent, which presumably indicates their homozygous recessive genotype of Rpf1 gene (rpf1rpf1).

1. Aleksandrov I.N., Skripka O.V., Dudchenko I.P., Surina T.A., Nikiforov S.V. Red stele root rot in strawberry. Zashchita i Karantin Ras-teniy = Plant Protection and Quarantine. 2007;5:32-34. (in Russian)

2. De los Santos B., Barrau C., Romero F. Strawberry fungal diseases. In: Crop Management and Postharvest Handling of Horticultural Products. 2004;4:233-268.

3. Denoyes-Rothan B., Guerin G., Lerceteau-Kohler E., Risser G. Inheritance of a race-specific resistance to Colletotrichum acutatum in Fragaria ananassa. Phytopathology. 2005;95:405-412. DOI 10.1094/PHYTO-95-0405.

4. Denoyes-Rothan B., Lerceteau-Kohler E., Guerin G., Bosseur S., Bariac J., Martin E., Roudeillac P. QTL analysis for resistance to Colletotrichum acutatum and Phytophthora cactorum in octoploid strawberry (Fragariax ananassa). Acta Hortic. 2004;663:147-151. DOI 10.17660/ActaHortic.2004.663.19.

5. Dudchenko I.P., Skripka O.V., Kopina M.B. Outbreak of strawberry anthracnose in the Voronezh region. Current Mycology in Russia: Materials of the III Int. Mycological Forum. Moscow, 2015;5(4):28-29. (in Russian)

6. Duncan J.M., Cowan J.B. Effect of temperature and soil moisture content on persistence and infectivity of Phytophthora fragariae in naturally infected soil. Trans. Br. Mycol. Soc. 1980;75:133-139.

7. FAOStat. 2018. Available at http://faostat3.fao.org/download/Q/QC/E.

8. Folta K.M., Davis T.M. Strawberry genes and genomics. Crit. Rev. Plant Sci. 2006;25:399-415. DOI 10.1080/07352680600824831.

9. Golovin S.E. New diseases of strawberries in the central Russia. Plodo-vodstvo i Yagodovodstvo Rossii = Pomiculture and Small Fruits Culture in Russia. 2014;1:88-95. (in Russian)

10. Haymes K.M., Van de Weg W.E., Arens P., Maas J.L., Vosman B., Den Nijs A.P.M. Development of SCAR markers linked to a Phytophthora fragariae resistance gene and their assessment in European and North American strawberry genotypes. J. Am. Soc. Hortic. Sci. 2000;125(3):330-339.

11. Hummer K., Hancock J.F. Strawberry genomics: botanical history, cultivation, traditional breeding, and new technologies. In: Folta K.M., Gardiner S.E. (Eds.). Genetics and Genomics of Rosaceae (ser. Plant Genetics and Genomics: Crops and Models). Springer, 2009;413-436.

12. Korbin M.U. Molecular approaches to disease resistance in Fragaria spp. J. Plant Prot. Res. 2011;51(1):60-65. DOI 10.2478/v10045-011-0011-2.

13. Leandro L.F.S., Gleason M.L., Nutter F.W., Jr., Wegulo S.N., Dixon P.M. Germination and sporulation of Colletotrichum acutatum on symptomless strawberry leaves. Phytopathology. 2001;91(7):659-664. DOI 10.1094/PHYTO.2001.91.7.659.

14. Lerceteau-Kohler E., Guerin G., Denoyes-Rothan B. Identification of SCAR markers linked to Rca2 anthracnose resistance gene and their assessment in strawberry germplasm. Theor. Appl. Genet. 2005; 111:862-870. DOI 10.1007/s00122-005-0008-1.

15. Lerceteau-Kohler E., Roudeillac P., Markocic M., Guerin G., Praud K., Denoyes-Rothan B. The use of molecular markers for durable resistance breeding in the cultivated strawberry (Fragaria x ananassa). Acta Hortic. 2002;567(2):615-618. DOI 10.17660/ActaHortic.2002.567.132.

16. Newton A.C., Duncan J.M., Augustin N.H., Guy D.C., Cooke D.E.L. Survival, distribution and genetic variability of inoculum of the strawberry red core pathogen, Phytophthora fragariae var. fragariae, in soil. Plant Pathol. 2010;59(3):472-479. DOI 10.1111/j.1365-3059.2010.02273.x.

17. Njuguna W. Development and Use of Molecular Tools in Fragaria. Oregon State Univ., 2010.

18. Sasnauskas A., Rugienius R., Gelvonauskiene D., Zalunskaite I., Staniene G., Siksnianas T., Stanys V., Bobinas C. Screening of strawberries with the red stele (Phytophthora fragariae) resistance gene Rpfl using sequence specific DNA markers. Acta Hortic. 2007; 760:165-169. DOI 10.17660/ActaHortic.2007.760.21.

19. Simpson D.W., Winterbottom C.Q., Bell J.A., Maltoni M.L. Resistance to a single UK isolate of Colletotrichum acutatum in strawberry germplasm from Northern Europe. Euphytica. 1994;77(1-2):161-164.

20. Smith B.J. Epidemiology and pathology of strawberry anthracnose: a North American perspective. HortScience. 2008;43(1):69-73.

21. Sturzeanu M., Coman M., Ciuca M., Ancu I., Cristina D., Turcu A.G. Molecular characterization of allelic status of the Rpfl and Rca2 genes in six cultivars of strawberries. Acta Hortic. 2016;1139:107-112. DOI 10.17660/ActaHortic.2016.1139.19.

22. Szkuta G. Czerwona zgnilizana korzeni truskawki [Red core of strawberry]. Ochrona Roslin. 2006;51:17-21.

23. Van de Weg W.E. Resistance to Phytophthora fragariae var. fragariae in strawberry: the Rpf2 gene. Theor. Appl. Genet. 1997a;94(8):1092-1096. DOI 10.1007/s001220050520.

24. Van de Weg W.E. A gene-for-gene model to explain interactions between cultivars of strawberry and races of Phytophthora fragariae var. fragariae. Theor. Appl. Genet. 1997b;94(3-4):445-451. DOI 10.1007/s001220050435.

25. Whitaker V.M. Applications of molecular markers in strawberry. J. Berry Res. 2011;1:115-127. DOI 10.3233/BR-2011-013.