Resistance in Common Bean to Uromyces Appendiculatus Under Field and Greenhouse Conditions

Abstract

Bean rust, caused by Uromyces appendiculatus, is a major disease in common bean which occurs annually in The Rhodope Mountains and sporadic in the plains of Bulgaria. The present study aims to find sources of resistance in common bean to the pathogen for using in a breeding program. The reaction of fifty-five Phaseolus vulgaris accessions to the pathogen was monitored under field condition. Infection type, disease intensity and area under the disease progress curve were calculated. Twelve common bean cultivars were inoculated with eight pathotypes of races 20-2, 20-16, and 20-18 in the greenhouse, and infection type was estimated. Twelve accessions had an immune reaction, eight accessions had resistant a reaction, two accessions had a middle resistant reaction, and seven accessions had a susceptible reaction to U. appendiculatus population in both field estimations. Five cultivars showed resistant phenotype to the eight pathotypes in the greenhouse, four of which were resistant in the field (Abritus, Beslet, Trakiya, and Prelom). Five cultivars had a susceptible or resistant reaction to the pathotypes of the same race, resulting from different interaction between resistant genes in the host and virulent genes in the pathogen. Nine accessions showed race-nonspecific resistance in the field expressed in low disease intensity and susceptible/resistant phenotype.

Resistance in Common Bean(phaseolus Vulgaris L.) to Uromyces Appendiculatus in Bulgaria

“…The results presented in Table 2 from a total of three investigations show that cultivars Abritus, Trakia, Pokrovnik and Prelom do not react with an identical reaction to different pathotypes referred to the same race of U. appendiculatus. Koleva and Kiryakov (2021) observed similar results in cultivars Ustrem and Pukliv 2. The authors explained the different infection type as the result of a different interaction between resistance genes in the host and virulent genes in the pathogen.…”

“…The cultivar shows a sensitive reaction to the pathotypes of races 29-1, 20-3, 52-3 and 20-0. Trakia cultivar is immune to the pathotypes of races 20-19, 20-3 and 20-18, sensitive to 29-0 and 29-1 and hypersensitive to all others pathotypes used by Beleva ( 2010) and Koleva and Kiryakov (2021). Compared by the rest, races 29-0 and 29-1 are the only ones that overcome race-specific genes Ur-4 (Early Gallatin) and Ur-9, Ur-12 (Pompadour Checa 50).…”

“…Therefore, results obtained under field conditions are confirmed or rejected under greenhouse conditions using a set of races/pathotypes. The results obtained in this way provide information about the interaction between race-specific gene in the cultivar and virulent gene in the pathogen, which is demonstrated only by IT (Koleva and Kiryakov, 2021). The Pokrovnik line shows immune reaction to races 20-0, 20-2 and 20-3 (Kiryakov and Genchev, 2004), immune reaction to pathotype of race 20-19, hypersensitive to 20-3 and 52-3, and sensitive reaction to pathotypes of races 29-0, 29-1 and 20-0 (Beleva, 2010) (Table 2).…”

“…The Pokrovnik line shows immune reaction to races 20-0, 20-2 and 20-3 (Kiryakov and Genchev, 2004), immune reaction to pathotype of race 20-19, hypersensitive to 20-3 and 52-3, and sensitive reaction to pathotypes of races 29-0, 29-1 and 20-0 (Beleva, 2010) (Table 2). The cultivar Abritus showed an immune phenotype to the three race 20-16 pathotypes used by Koleva and Kiryakov (2021), as well as to two of the pathotypes of race 20-18. To the other two pathotypes of the same race, the cultivar shows resistant reaction, as well as to the pathotypes of races 29-0, 20-19 and 20-2 used by Beleva (2010).…”

“…Pastor-Corrales and Stavely (30) proposed a method for identifying race-specific genes using a set of races. Following this method is possible to suppose that cultivar Trakiya has a combination of race-specific genes Ur-4 and Ur-9 (Ur-12 govern adult plant resistance) but additional investigations have to be made to confirm or reject this supposal (Koleva and Kiryakov, 2021). The cultivar Prelom shows an immune, hypersensitive or resistant reaction to the pathotypes of races 20-2, 20-16 and 20-18 used by Koleva and Kiryakov (2021), recently identified and distributed in North-Eastern Bulgaria (Koleva and Kiryakov, 2020).…”