Location: Grape Genetics Research Unit (GGRU)Title: QTL mapping of downy mildew and botrytis bunch rot resistance in a Vitis aestivalis-derived 'Norton'-based population
|SAPKOTA, SURYA - Cornell University - New York|
|CHEN, LI-LING - Missouri State University|
|YANG, SHANSHAN - Cornell University - New York|
|HYMA, KATIE - Cornell University - New York|
|HWANG, CHIN-FENG - Missouri State University|
Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2018
Publication Date: 11/11/2019
Citation: Sapkota, S.D., Chen, L.L., Yang, S., Hyma, K.E., Cadle-Davidson, L.E. and Hwang, C.F. 2019. Quantitative trait locus mapping of downy mildew and botrytis bunch rot resistance in a Vitis aestivalis-derived 'Norton'-based population. Acta Hortic. 1248:305-312. https://doi.org/10.17660/ActaHortic.2019.1248.44.
Interpretive Summary: ‘Norton’ is the official grape of Missouri. It is grown where European grapes perform poorly due to disease or cold. Norton’s natural resistance to the elements makes it a useful parent for improving European grapes by traditional breeding. To identify the genetic basis for resistance to downy mildew and Botrytis bunch rot, ‘Norton’ and ‘Cabernet Sauvignon’ were cross-hybridized to make a mapping family of 182 seedlings. Genetic resistance to downy mildew and Botrytis bunch rot was measured in this family for two years. A genetic map was constructed using 2,072 DNA markers across the 19 grape chromosomes. DNA markers on chromosome 18 predicted resistance to downy mildew, and DNA markers on chromosome 2 predicted resistance to Botrytis bunch rot. These DNA markers can be used to accelerate breeding to combine disease resistance with European grape quality.
Technical Abstract: Vitis aestivalis-derived ‘Norton’ is the official grape of the State of Missouri grown in regions with high disease pressure and cold winter temperatures where V. vinifera is not adapted. It reportedly offers an abundance of traits, including resistance to powdery and downy mildew as well as Botrytis bunch rot, which can be used to naturally improve existing V. vinifera germplasm. To identify genetic determinants for resistance to downy mildew caused by Plasmopara viticola and Botrytis bunch rot caused by Botrytis cinerea in V. aestivalis-derived ‘Norton’, a mapping population of 182 individuals was constructed from a cross between ‘Norton’ and V. vinifera ‘Cabernet Sauvignon’. A consensus genetic map was constructed with 411 simple sequence repeat (SSR) markers. In collaboration with VitisGen (www.vitisgen.org), approximately 43,320 single nucleotide polymorphism (SNP) markers generated by genotyping-by-sequencing (GBS) were identified, and a consensus map of 3,825 SNPs was developed. Of these, 1,665 SNP and 407 SSR markers were clustered into 19 linkage groups for a total of 2,072 markers spanning a genetic distance of 2,203.5 cM. In preparation for placing traits on this integrated high-resolution map, disease progression and resistance reaction in response to P. viticola and B. cinerea were evaluated in this population for two years. The quantitative trait loci (QTL) analysis indicated a major resistance locus on linkage group 18 for downy mildew and linkage group 2 for Botrytis bunch rot, respectively. The ultimate goal of this program is to use genetic markers to rapidly deploy favorable alleles and accelerate breeding cycles for new cultivar releases.