Reaction to Three Races of Fusarium Wilt in the Phaseolus vulgaris Core Collection

Abstract

Seven races of Fusarium oxysporum f. sp. phaseoli Kendrick and Snyder (Fop) cause Fusarium wilt (FW) disease of common bean (Phaseolus vulgaris L.). FW occurs worldwide and has recently become a serious disease in the central and western USA. The objectives of this research were to identify new sources of resistance to Fop, characterize the Central/South American (CA/SA) Phaseolus Core Collection for reaction to races 1, 4, and 5 Fop and determine if a previously reported sequence characterized amplified region (SCAR) molecular marker would be useful to identify resistance among accessions that make up the CA/SA Core Collection. Seedlings from the CA/SA Core Collection were screened for reaction by a root dip inoculation procedure. Among accessions evaluated for reaction to race 1 Fop, 21 were resistant, 47 intermediate, and 126 susceptible. Fifteen accessions were resistant to race 4, 61 intermediate, and 114 were susceptible. Nine accessions were resistant to both races 1 and 4, and five of the nine (PI 207373, PI 307802, PI 308908, PI 309877, PI 310842) were also resistant to race 5 Fop. All accessions resistant to races 1, 4, and 5 of Fop were characterized as Middle American, which suggests that resistance to multiple races of Fop should be more prevalent in germplasm from Middle America. The SCAR marker previously developed to identify a quantitative trait locus (QTL) associated with resistance to Fop was not associated with resistance in the Core Collection.

Identification and Confirmation of Quantitative Trait Loci for Root Rot Resistance in Snap Bean

“…Regions located in linkage group B2 and B5 were associated with root rot resistance; however, neither of these linkage groups were associated with root rot resistance in the present study. The lack of agreement of the results of the present study with previous studies (Fall et al, 2001; Román‐Avilés and Kelly, 2005; Brick et al, 2006) may be partially due to their focus on Fusarium wilt and Fusarium root rot and supports previous reports that Fusarium spp. do not play a significant role in the root rot complex evaluated at Hancock, WI (Boomstra, 1975; Beebe and Bliss, 1979).…”

“…Fall (2001) also developed a sequence characterized amplified region (SCAR) marker to facilitate the large scale use of the linkage relationship between U20.750 and resistance to Fusarium wilt. Brick et al (2006) evaluated the SCAR marker developed by Fall (2001) to determine its usefulness to characterize resistance to Fusarium wilt in 202 accessions that represented the USDA Central and South American P. vulgaris core collection. Results indicated that amplification of the SCAR marker developed by Fall (2001) was not associated with resistance to F. oxysporum f. sp.…”

“…f. sp. phaseoli J.B. Kendrick and W.C. Snyder) has also been identified using an independent RIL population (Fall et al, 2001; Fall, 2001); however the QTL identified was not useful in identifying lines with resistance to Fusarium wilt in germplasm of the core collection (Brick et al, 2006).…”

Forming Core Collections in Barnyard, Kodo, and Little Millets using Morphoagronomic Descriptors

“…The availability of core collections in these neglected crops provides researchers opportunity to discover new sources of variation for use in genetic improvement of these crops. To date, research at ICRISAT and elsewhere has proven beyond doubt the utility of these representative subsets in identifying agronomically beneficial germplasm for use in crop breeding (Bowman et al, 2001;Brick et al, 2006;Grunwald et al, 2003;Mahuku et al, 2003;Micklas et al, 1999;Tullu et al, 2001;Upadhyaya et al, 2013Upadhyaya et al, , 2014. Molecular characterization of these subsets should further provide information on population structure and diversity and allelic richness, which may be used to identify genetically diverse germplasm for use in genomics and applied breeding of these crops.…”

Population structure and genetic differentiation among the USDA common bean (Phaseolus vulgaris L.) core collection

“…A number of studies have accessed diversity in the CIAT collection (Tohme et al 1996;Beebe et al 2000Beebe et al , 2001Blair et al 2006;Diaz and Blair 2006). Fewer studies of the diversity in the NPGS have been performed (Miklas et al 1999;Brick et al 2006).…”