Genetic study of Botrytis bunch rot resistance in grapevine

Surya Sapkota, MSU Graduate Student
Li-Ling Chen, Missouri State University
Chin-Feng Hwang, Missouri State University

Abstract

Grape bunch rot, caused by the necrotrophic fungal pathogen Botrytis cinerea, is one of the most destructive diseases in grapevines worldwide. At this point, control of Botrytis bunch rot is achieved through a combination of canopy management and fungicide usage. The identification of resistant germplasm could result in improved disease management. The Vitis aestivalis-derived 'Norton' is one of the very few commercial red grape cultivars that can be grown under elevated B. Cinerea pressure where highly susceptible V. Vinifera is difficult to grow. Tests on the F progeny from a cross between V. Aestivalis-derived 'Norton' and V. Vinifera 'Cabernet Sauvignon' may elucidate the underlying genetic and molecular mechanisms of berry disease resistance and berry quality. To this end, we have developed a population of 92 F genotypes from this cross that has yielded fruit for the past three years. Also, a linkage map employing simple sequence repeat (SSR) markers clustered in 19 chromosomes has been under construction. By using genotyping-by-sequencing (GBS) technology as part of the VitisGen (www.vitisgen.org) project, we aim to improve marker-density and identify the tightly linked markers associated with Botrytis bunch rot resistance. The overall goals of this study are to use genetic markers to rapidly implement favorable alleles and accelerate breeding cycles for new improved cultivar releases that warrant decreased pesticide use in the vineyard, resulting in greater environmental and economic sustainability. 1 1