Author
BRISCO, E. - Michigan State University | |
Porch, Timothy - Tim | |
Cregan, Perry | |
KELLY, J. - Michigan State University |
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/1/2014 Publication Date: 6/2/2014 Citation: Brisco, E.I., Porch Clay, T.G., Cregan, P.B., Kelly, J.D. 2014. Identification of QTL associated with resistance to leafhopper species Empoasca fabae and Empoasca kraemeri in common bean. Crop Science. doi:10.2135/cropsci2014.02.0159. Interpretive Summary: Leafhoppers, within the Empoasca species, are a major insect pest of common bean that cause significant economic losses in both tropical and temperate regions of the Americas. The objective of this study was to use molecular markers to identify genetic regions, or quantitative trait loci (QTL), associated with traits related to leafhopper resistance in common bean. Traits for leaf curl and leaf burn damage as well as Empoasca spp. nymph counts were evaluated in a population of beans in temperate (Michigan) and tropical (Puerto Rico) climates. Fourteen QTL associated with resistance were identified on five chromosomes explaining up to 66 % of the resistance response. A major QTL associated with multiple resistance traits and closely linked to a seed color gene was detected for both leafhopper species in multiple seasons on bean chromosome Pv07, thus validating results in previous studies. A novel genetic region for E. fabae nymph counts was identified on chromosome Pv02 that may be associated with antibiosis resistance, where the plants resistance mechanism is detrimental to the insect. Resistance to each leafhopper species appears to be controlled by separate genetic mechanisms in common bean as there was little overlap of QTL between species. These genetic regions and associated molecular markers could be used to develop beans with leafhopper resistance as an alternative to costly chemical control while reducing risks to the environment and human health. Technical Abstract: Empoasca species leafhoppers are a major insect pest of common bean, Phaseolus vulgaris that cause significant economic losses in both tropical (E. kraemeri) and temperate (E. fabae) regions of the Americas. The objective of this study was to use Indel and single nucleotide polymorphism (SNP) markers from the BARCBean6K_3 Beadchip to identify quantitative trait loci (QTL) associated with traits related to leafhopper resistance in common bean. Traits for leaf curl and leaf burn damage as well as Empoasca spp. nymph counts were evaluated in an inbred backcross line population (Matterhorn*/EMP507) of beans in temperate (Michigan) and tropical (Puerto Rico) climates. Fourteen QTL associated with resistance to E. fabae and E. kraemeri were identified on five chromosomes explaining up to 66.0 % of the phenotypic variation in single resistance traits. A major QTL cluster associated with multiple resistance traits and closely linked to the P color gene was detected for both leafhopper species in multiple seasons on Pv07 (LH7.1, LH7.2, LH7.3), thus validating a similar QTL identified in previous studies. A novel QTL for E. fabae nymph counts was identified on Pv02 that may be associated with antibiosis resistance. Resistance to each leafhopper species appears to be controlled by separate genetic mechanisms in common bean as there was little overlap of QTL regions between species. These QTL could be used to develop beans with leafhopper resistance as an alternative to costly chemical controls while reducing risks to the environment and human health. |