RT Journal Article SR Electronic T1 Evaluating Grapevine Cultivars for Resistance to Anthracnose Based on Lesion Number and Length JF American Journal of Enology and Viticulture JO Am. J. Enol. Vitic. FD American Society for Enology and Viticulture SP 262 OP 268 DO 10.5344/ajev.2012.11109 VO 63 IS 2 A1 Atsushi Kono A1 Akihiko Sato A1 Masaaki Nakano A1 Masahiko Yamada A1 Nobuhito Mitani A1 Yusuke Ban YR 2012 UL http://www.ajevonline.org/content/63/2/262.abstract AB Anthracnose is one of the most detrimental diseases of grapevines in humid regions. To lessen the risk of crop damage and to reduce fungicide application, resistant cultivars are needed. The resistance of grapevines to anthracnose caused by Elsinoƫ ampelina (de Bary) Shear was evaluated in two ways: the resistance against ingress was evaluated using the number of lesions and the resistance against colonization was evaluated using the lesion length. First, both forms of resistance in 13 cultivars were evaluated in a detached-leaf assay for three years using greenhouse-grown cuttings. Both lesion number and lesion length revealed a genetic component of the resistance, with greater phenotypic variation among interspecific hybrid cultivars than among Vitis vinifera cultivars. The detached-leaf assay revealed significant differences in lesion length among V. vinifera accessions; Exotic and Perlette showed moderate resistance. Lesion diameters were measured in a fungicide-free vineyard to evaluate the resistance of six cultivars, and significant differences were found among the cultivars. The lesion shape in susceptible cultivars was almost circular, whereas the shape in resistant cultivars was usually irregular. Results showed that evaluations based on the lesion number and length can reliably predict resistance to anthracnose without the need for large field trials and that some V. vinifera cultivars exhibited moderate resistance to this disease.