|NOH, YOUNG-HEE - University Of Florida|
|MANGANDI, JOZER - University Of Florida|
|VERMA, SUJEET - University Of Florida|
|LU, YI-TIEN - University Of Florida|
|FAN, ZHEN - University Of Florida|
|PERES, NATALIA - University Of Florida|
|WHITAKER, VANCE - University Of Florida|
|LEE, SEONGHEE - University Of Florida|
Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2018
Publication Date: 7/30/2018
Citation: Noh, Y., Mangandi, J., Verma, S., Zurn, J.D., Lu, Y., Fan, Z., Bassil, N.V., Peres, N., Whitaker, V.M., Lee, S. 2018. Development and validation of marker assays for high-throughput detection of Phytophthora crown rot resistance, FaRPc2, in the cultivated octoploid strawberry. Molecular Breeding. 38:104.
Interpretive Summary: Phytophthora crown rot is a destructive root disease of cultivated strawberries. In a previous study, the resistance locus FaPc2 was identified to provide good resistance to the disease. To help imporving breeding of new resistant strawberry cultivars, a diagnostic test for the resistance locus was needed. The work presented describes the development of three DNA tests which can be used to help breeders select individuals with the FaPc2 resistance. These tests were found to work best in varieties developed by the University of Florida and some of the varieties produced by the University of California Davis. These two programs are amoung the largest public breeding progams and these tests can help develop numerous new resistant varieties.
Technical Abstract: Phytophthora crown rot (PhCR) caused by Phytophthora cactorum is a destructive disease of the allo-octoploid cultivated strawberry (Fragaria ×ananassa). Many major strawberry cultivars grown worldwide are susceptible to PhCR. Genetic resistance was detected in the University of Florida (UF) breeding program and was found to be primarily controlled by the FaRPc2 locus. In the current study, we developed DNA markers for two haplotypes associated with resistance, H2 and H3, at FaRPc2. Marker validation and marker-assisted selection were performed in breeding populations. Seven single nucleotide polymorphism (SNP)-based high resolution melting (HRM) markers linked to H2 and four HRM markers for H3 were developed. One HRM marker, RPCHRM3, linked to H3 was converted to a Kompetitive Allele Specific PCR (KASP) marker. To examine the accuracy of marker selection in breeding populations, all markers associated with FaRPc2 were tested in 206 UF breeding accessions in addition to 38 diverse accessions preserved at the USDA-ARS National Clonal Germplasm Repository, in Corvallis, Oregon. The most informative markers for H2 and H3 are being implemented in the UF strawberry breeding program to improve PhCR resistance.