Variation in Reaction to Fusarium spp. Identified in a Common Bean (Phaseolus vulgaris L.) Population Developed for Field‐Based Resistance to Root Rot and Wilt

Abstract

Fusarium oxysporum f. sp. phaseoli (FOP) and Fusarium solani f. sp. phaseoli (FSP) cause wilt and root rot symptoms in beans (Phaseolus vulgaris L.) and frequently cause a reduction in pod yield. The objectives of this study were to determine the degree of phenotypic variation for reaction to FOP and FSP present in an ‘Eagle’ × Puebla 152 (EP) recombinant inbred line (RIL) population and to determine if previously identified quantitative trait loci (QTLs) associated with resistance to Aphanomyces euteiches were consistent with those associated with resistance to FOP and FSP. Transgressive segregation was observed among the EP RILs for reaction to FOP. The narrow sense heritabilities for resistance to FOP based on foliar and root symptoms were 0.25 ± 0.07 and 0.29 ± 0.07, respectively. Similarly, the narrow sense heritability for resistance to FSP was 0.23 ± 0.12. Random amplified polymorphic DNA (RAPD) markers W13.350 on linkage group B6 and AG13.600 on linkage group B8 were associated with QTLs for root and foliar response to FOP; an additional RAPD marker, U12.500 on linkage group B2, was associated with foliar response to FOP. Selection for QTLs associated with resistance to FOP should result in bean lines with reduced severity to both foliar and root symptoms caused by FOP. Two QTLs, AM2.400 and U20.1150 on linkage groups B3 and B8, respectively, were identified as associated with resistance to FSP. The QTLs associated with FOP, FSP, and A. euteiches are independent, indicating that it may be possible to use RAPD markers to pyramid resistance to all three soil borne pathogens.