PHENOTYPIC AND MOLECULAR SCREENING OF DRY BEAN (Phaseolus vulgaris L.) BREEDING LINES FOR RESISTANCE TO bean common mosaic virus AND bean common mosaic necrosis virus

Abstract

Bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV) are among the most economically important virus species infecting common bean. The use of resistant plant cultivars is the most effective way to control these viruses. In this study, 204 breeding lines were tested for resistance levels to BCMV and BCMNV. Initially, BCMNV NL-3 and BCMV NL-4 strains were individually sap-inoculated onto the leaves of bean plants belonging to each breeding lines with 10 replications, and the reactions of plants were evaluated for symptomatic appearance of virus infection 21 days after inoculation. Two sets of plants from each line were inoculated with NL-3 and NL4 respectively. Additionally, molecular markers linked to resistance genes confirmed phenotypic evaluation. As a result, 153 breeding lines were found to carry the dominant I gene whereas four and five of the tested lines had the recessive genes bc-1² and bc-2², respectively. In conclusion, these resistant breeding lines could be proposed to be registered as new improved cultivars after evaluating them in terms of yield and grain quality. In addition, seeds of the resistant breeding lines can be used as the source of virus-resistant germplasm in breeding studies and be maintained at the national genebank facility in Turkey.