Genetic control and combining ability of resistance to American mildew, Septoria leaf spot and gall mite in black currant

Abstract

The character of gene interaction determining resistance to fungal diseases and gall mite was investigated by topcrossing method in black currant cultivars and forms of different genetic nature. For crossings three maternal varieties (testers) and seven paternal varieties and forms of different resistance to American mildew, Septoria leaf spot and gall mite were employed. Eleven cultivars and forms were assessed that differed in combining ability of resistance to fungal diseases and gall mite. Resistance to American mildew (Sphaerotheca mors-uvae) and Septoria leaf spot (Mycosphaerella ribis) is determined by genes with additive effects. In genetic control for resistance to gall mite (Cecidophyopsis ribis) important are both genes - with additive and non-additive (dominant and epistatic) effects. Black currant form D16/1/-25 was ascertained to be a donor of resistance to American mildew and Septoria leaf spot and cultivar Ben Gairn - a donor of resistance to gall mite.

Keywords

• black currant
• combining ability
• genetic control
• sphaerotheca mors-uvae
• mycosphaerella ribis
• cecido-phyopsis ribis