Mold In Common Bean Research Articles

Colony Age of Trichoderma azevedoi Alters the Profile of Volatile Organic Compounds and Ability to Suppress Sclerotinia sclerotiorum in Bean Plants.

Common bean (Phaseolus vulgaris L.) is one of the most important crops in human food production. The occurrence of diseases, such as white mold, caused by Sclerotinia sclerotiorum can limit the production of this legume. The use of Trichoderma has become an important strategy in the suppression of this disease. The aim of the present study was to evaluate the effect of volatile organic compounds (VOCs) emitted by Trichoderma azevedoi CEN1241 in five different growth periods on the severity of white mold in common bean. The in vitro assays were carried out in double-plate and split-plate, and the in vivo assays, through the exposure of the mycelia of S. sclerotiorum to the VOCs of T. azevedoi CEN1241 and subsequent inoculation in bean plants. Chemical analysis by gas chromatography coupled to mass spectrometry detected 37 VOCs produced by T. azevedoi CEN1241, covering six major chemical classes. The profile of VOCs produced by T. azevedoi CEN1241 varied according to colony age and was shown to be related to the ability of the biocontrol agent to suppress S. sclerotiorum. T. azevedoi CEN1241 VOCs reduced the size of S. sclerotiorum lesions on bean fragments in vitro and reduced disease severity in a greenhouse. This study demonstrated in a more applied way that the mechanism of antibiosis through the production of volatile compounds exerted by Trichoderma can complement other mechanisms, such as parasitism and competition, thus contributing to a better efficiency in the control of white mold in bean plants.

Draft genome sequence of Bacillus sp. strain FSQ1, a biological control agent against white mold in common bean (Phaseolus vulgaris L.).

Bacillus sp. strain FSQ1 was isolated from the common bean (Phaseolus vulgaris L.). The genome of this strain presented 3,598,499bp; 43.0% G+C content; 925,913bp N50; 2 L50; 33 contigs; 97 RNAs and 3,908 predicted coding DNA sequences (CDS) distributed in 315 subsystems. Based on genome mining, the biological control activity of strains FSQ1 could be associated with the biosynthesis of rhizocticin A and bacillibactin. Thus, this strain is a promising active ingredient for the formulation of biopesticides.

Phosphonates and SAR-trigger elicitors reducing the intensity of white mold in common bean

White mold caused by the fungus Sclerotinia sclerotiorum is one of the main common bean diseases. The aim of this study was to evaluate the effect of phosphonates and elicitors in reducing the severity of white mold. The experiment was carried out in a randomized block design with six treatments and six replications in a split-plot, where each experimental plot consisted of one bean plant. The treatments were acibenzolar-S-methyl—ASM (500 g L−1) 0.25 g L−1, chitosan (85% deacetylation) 50 mg L−1, fluazinam (500 g L−1) 120 g L−1, copper phosphite (275 g L−1) 250 g L−1, and copper ethylphosphonate (20% P2O5 + 1.75% S + 3.5% Cu) 5 mL L−1 and control. Inoculation was performed 28 DAS, and assessment of disease severity was conducted 8 days after inoculation (DAI) using a grade scale. The parameters evaluated were photosystem II (PSII) quantum yield (Fv/Fm) and total chlorophyll content 3, 6, and 9 days after application (DAA) of the chemicals and 3, 6, and 8 DAI. Statistical analyses were performed using R Statistical Software. The phytosanitary chemicals herein evaluated promoted lower intensity of S. sclerotiorum infection in common bean plants compared to the control. No decrease in chlorophyll content was observed, but there was a reduction in Fv/Fm values in inoculated plants compared with uninoculated plants caused by S. sclerotiorum infection, which resulted in damage to the photochemical step of photosynthesis. In this sense, the tested phosphonates and elicitors, especially ASM and copper ethylphosphonate, enhanced protection and reduced disease severity.

Management of white mold in common bean using partial resistance and fungicide applications

White mold (WM) is a damaging disease of common bean in Brazil and fungicide applications can effectively control it. However, in the absence of fungicide, some type III bean genotypes have exhibited less WM disease and higher yields under field conditions than the current Brazilian cultivars. Here we assessed the possibility of reducing the number of foliar fungicide applications to control WM using genotypes partially resistant to WM. The production of sclerotia was also assessed. We conducted sprinkler-irrigated trials combining genotypes (susceptible, moderately resistant or partially resistant to WM) with a number of fluazinam applications (0, 1, 2 or 3) under low, low/moderate, moderate or high WM pressure. Under low and low/moderate pressure, one fungicide application reduced WM disease for the susceptible genotype, but did not affect WM disease for the partially resistant genotype. In these conditions, fungicide did not affect yield for either of the genotypes. Under moderate and high pressure and in the cross-site analysis, genotype-by-fungicide interactions were nonsignificant for WM incidence, WM severity index, yield and sclerotia weight. Averaged across site and fungicide, the partially resistant genotype presented a 30% lower WM severity index and produced 2.3-fold fewer sclerotia than the susceptible genotype. We conclude that partially field-resistant beans may contribute to the integrated management of WM, with a potential, at least under light pressure, to reduce the use of fungicide.

Biochemical responses of common bean to white mold potentiated by phosphites

Considering that the mechanisms for phosphite-afforded disease control remain elusive, this study investigated whether zinc (Zn) and copper (Cu) phosphites could possible potentiate common bean resistance to white mold, caused by Sclerotinia sclerotiorum, through the stimulation of biochemical defence responses. Lesion area and disease severity were decreased by phosphites spray, but Zn phosphite outcompeted Cu phosphite. Histopathological observations revealed fewer fungal hyphae and less collapse of the mesophyll cells in the Zn and Cu phosphite-sprayed plants compared to water-sprayed ones. The S. sclerotiorum-triggered accumulation of reactive oxygen species, oxalic acid (a fungal secreted toxin) and malondialdehyde (an indicator of cellular damage) were constrained as a result of Zn and Cu phosphites spray. Activities of antioxidant enzymes (superoxide dismutase, peroxidase, ascorbate peroxidase and glutathione-S-transferase at 12 h after inoculation (hai) and catalase at 60 and 84 hai) were higher for Zn and Cu phosphites-sprayed plants than for water-sprayed ones. Activities of defence-related enzymes chitinase (CHI) at 12 hai, β-1,3-glucanase (GLU) and polyphenoloxidase (PPO) were higher at 12–84 hai for Zn, and Cu phosphites sprayed plants, phenylalanine ammonia-lyase at 36–84 hai for the Zn phosphite sprayed ones, CHI at 12–36 hai, GLU at 12–60 hai, PPO at 36 hai and PAL and lipoxygenase at 12 hai for the Cu phosphite sprayed ones upon inoculation with S. sclerotiorum relative to their water-sprayed counterparts. Concentrations of total soluble phenols and lignin-thioglycolic acid derivatives were not affected by Cu phosphite spray on infected plants but were higher and lower, respectively, for Zn phosphite sprayed plants at 60 hai compared to water-sprayed ones. Taken together, the findings from the present study shed light on the biochemical defence mechanisms involved in the Zn and Cu phosphites-mediated suppression of white mold in common bean.

Fungitoxicity activity of Phosphorus and Calcarea carbonica against Sclerotinia sclerotiorum and control of white mold in common bean (Phaseolus vulgaris) with extremely diluted aqueous solutions

Common bean (Phaseolus vulgaris L.) is one of the main Brazilian agricultural crops. Numerous diseases have affected such a crop during its life cycle, such as white mold, caused by Sclerotinia sclerotiorum. This fungus is quite aggressive and requires an intensive use of pesticides. This study aimed at evaluating white mold control and antimicrobial activity against S. sclerotiorum using extremely diluted aqueous solutions of Phosphorus and Calcarea carbonica, at 6CH, 12CH, 24CH, 36CH and 48CH dynamizations (centesimal Hahnemannian). The tests were carried out in a completely randomized design, with 10 treatments and 5 replicates each, considering water as control. Variables including disease progression, the number of dead plants, the number of sclerotia, and mycelial growth were evaluated by in vivo and in vitro tests. The treatments Phosphorus 12CH, Phosphorus 48CH, Calcarea carbonica 12CH, and Calcarea carbonica 48CH presented resistance-inducing action by slowing down the disease progression up to 83% and decreasing the number of dead plants up to 90%. In vitro tests showed that the treatments Phosphorus 12CH, Phosphorus 48CH and Calcarea carbonica 48CH slowed down the mycelial growth. The latter also completely inhibited the production of sclerotia. These results indicate the potential of Phosphorus 12CH, Phosphorus 48CH, Calcarea carbonica 12CH, and Calcarea carbonica 48CH for controlling S. sclerotiorum in common beans.

Incidence and severity of white mold in common bean submitted to different cultivation practices

ABSTRACT Due to the socioeconomic importance of common bean in Brazil, studies that allow establishing favorable conditions for not compromising the crop with white mold, in view of the enormous damages caused by this fungus, become vital to Brazilian agriculture. Therefore, the aim of this study was to evaluate the incidence and severity of white mold in common bean (Phaseolus vulgaris L.), cultivar ‘Madrepérola’, subjected to different irrigation intervals, planting densities and fungicide application. The research was conducted in Viçosa-MG, Brazil, in the years 2011 and 2012. The statistical analysis used the split-split-plot scheme. The fungicide applications (with or without fungicide) were allocated to plots, the irrigation intervals (3, 6, 9 and 12 days) to sub-plots and planting densities (6, 9, 12 and 15 plants per linear meter) to sub-subplots, in a randomized block design with three replicates. The variation of the irrigation intervals did not contribute significantly to the control of white mold. It is recommended to use lower planting densities in order to minimize the damages caused by the disease. The use of the fungicide was the main method of white mold control in two consecutive years.

Meta-QTL for resistance to white mold in common bean.

White mold, caused by the fungus Sclerotinia sclerotiorum (Lib.) de Bary, is a major disease that limits common bean production and quality worldwide. The host-pathogen interaction is complex, with partial resistance in the host inherited as a quantitative trait with low to moderate heritability. Our objective was to identify meta-QTL conditioning partial resistance to white mold from individual QTL identified across multiple populations and environments. The physical positions for 37 individual QTL were identified across 14 recombinant inbred bi-parental populations (six new, three re-genotyped, and five from the literature). A meta-QTL analysis of the 37 QTL was conducted using the genetic linkage map of Stampede x Red Hawk population as the reference. The 37 QTL condensed into 17 named loci (12 previously named and five new) of which nine were defined as meta-QTL WM1.1, WM2.2, WM3.1, WM5.4, WM6.2, WM7.1, WM7.4, WM7.5, and WM8.3. The nine meta-QTL had confidence intervals ranging from 0.65 to 9.41 Mb. Candidate genes shown to express under S. sclerotiorum infection in other studies, including cell wall receptor kinase, COI1, ethylene responsive transcription factor, peroxidase, and MYB transcription factor, were found within the confidence interval for five of the meta-QTL. The nine meta-QTL are recommended as potential targets for MAS for partial resistance to white mold in common bean.

Biological control of white mold by Trichoderma harzianum in common bean under field conditions

Abstract: The objective of this work was to evaluate Trichoderma harzianum isolates for biological control of white mold in common bean (Phaseolus vulgaris). Five isolates were evaluated for biocontrol of white mold in 'Perola' common bean under field conditions, in the 2009 and 2010 crop seasons. A commercial isolate (1306) and a control treatment were included. Foliar applications at 2x109 conidia mL-1 were performed at 42 and 52 days after sowing (DAS), in 2009, and at 52 DAS in 2010. The CEN287, CEN316, and 1306 isolates decreased the number of Sclerotinia sclerotiorum apothecia per square meter in comparison to the control, in both crop seasons. CEN287, CEN316, and 1306 decreased white mold severity during the experimental period, when compared to the control.

Identification of QTLs of resistance to white mold in common bean from multiple markers by using Bayesian analysis.

In this study, we identified simple sequence repeat, ampli-fied fragment length polymorphism, and sequence-related amplified poly-morphism markers linked to quantitative trait loci (QTLs) for resistance to white mold disease in common bean progenies derived from a cross between lines CNFC 9506 and RP-2, evaluated using the oxalic acid test and using Bayesian analysis. DNA was extracted from 186 F₂ plants and their parental lines for molecular analysis. Fifteen experiments were car-ried out for phenotypic analysis, which included 186 F₂:₄ progenies, the F₁ generation, the F₂ generation, and the lines CNFC 9506, RP-2, and G122 as common treatments. A completely randomized experimental design with 3 replications was used in controlled environments. The adjusted means for the F₂:₄ generation were to identify QTLs by Bayesian shrink-age analysis. Significant differences were observed among the progenies for the reaction to white mold. The moving away method under the Bayes-ian approach was effective for identifying QTLs when it was not possible to obtain a genetic map because of low marker density. Using the Wald test, 25 markers identified QTLs for resistance to white mold, as well as 16 simple sequence repeats, 7 amplified fragment length polymorphisms, and 2 sequence-related amplified polymorphisms. The markers BM184, BM211, and PV-gaat001 showed low distances from QTLs related white mold resistance. In addition, these markers showed, signal effects with increasing resistance to white mold and high heritability in the analysis with oxalic acid, and thus, are promising for marker-assisted selection.

Identification of QTL for agronomic traits and resistance to white mold in wild and landrace germplasm of common bean

With 1 figure and 5 tablesAbstractWhite mold, caused by Sclerotinia sclerotiorum (Lib.) De Bary, is a serious yield reducing fungal pathogen of common bean (Phaseolus vulgaris L.). Our objective was to identify QTL for resistance to white mold from wild and landrace accessions of common bean using two inbred backcross line (IBL) populations derived from the recurrent black bean parent ‘Tacana’. Selective phenotyping failed to detect QTL for field disease resistance but other agronomic traits less sensitive to environmental conditions or population size were detected. Four novel QTLs for white mold resistance WM3.3TW, WM7.5TL, WM9.2TW, and WM11.1TL were identified in the greenhouse straw test on linkage groups B3, B7, B9, and B11, respectively, and two previously mapped QTL were also validated on B2 and B4. QTL, SY2.1TL that accounted for 19–37% of the variation for yield under white mold pressure over 3 years, was detected on B2 in the TL population. Enhanced resistance to white mold in common bean could be achieved by combining different QTL associated with physiological resistance with yield under disease pressure.

Marker-assisted backcrossing using microsatellites and validation of SCAR Phs marker for resistance to white mold in common bean

Molecular markers may accelerate selection through the identification of plants with higher proportion of recurrent parent genome, as well as identifying those plants bearing target alleles like quantitative traits loci (QTLs) for white mold resistance. The objectives of this work were: 1) to employ microsatellite markers (SSR) in order to accelerate the recovery of recurrent parent genome 2) to validate sequence characterized amplified region (SCAR) Phs associated with a QTL that confers resistance to white mold, as previously identified in bean populations. Lines G122 and M20 were crossed, which generated 267 F 1 plants from backcross (BC) BC 1 and 113 plants from backcross BC 2 .SSR polymorphic markers were adopted. The relationship between BC plants and the recurrent parent was estimated based on the recurrent genome proportion (PR) in each BC plant, and the Sorensen-Dice genetic similarity ( sg ir ). To determine how much the phenotypic variation is explained by SCAR Phs , 56 F 1:2 BC 1 progenies were evaluated on the field following a random block design with two replications through the straw test method. SSR markers are efficient in identifying individuals with a greater proportion of the recurrent genome. SCAR Phs was not efficient for the indirect selection of common beans for white mold resistance.

Gamete and recurrent selection for improving physiological resistance to white mold in common bean

White mold (WM) is a widely distributed and severe disease of common bean in North America. The objective of this study was to determine the effectiveness of gamete (GS) and recurrent (RS) selection methods for improving WM resistance. Two double-crosses, namely USPT-WM-1/CORNELL 601//USPT-CBB-1/92BG-7 and ‘Chas’/I 9365-25//ABL 15/A 195 were made. Equal numbers of progenies from both crosses were subjected to GS and RS. The GS was practiced from F1 to F4 by selecting WM resistant single plants followed by progeny testing in the subsequent generation. Two cycles of RS were practiced by intermating selected WM resistant plants in each cycle. Thirteen selected families in each method and parents were evaluated at 16, 23, and 33 days post first inoculation in replicated trials in two greenhouse environments. Higher frequencies of families with lower WM scores were obtained from GS than RS. The average genetic gains due to GS and RS were 19.6 and 7.9%, respectively. Employing multiple-parent-crosses involving parents of diverse evolutionary origins delayed WM evaluation, and application of GS are recommended for improving physiological WM resistance in common bean.Key words: Interspecific breeding line, introgressing resistance, multiple-parent crosses, Phaseolus vulgaris, pyramiding resistance, Sclerotinia sclerotiorum

Gamete selection for improving physiological resistance to white mold in common bean

White mold (WM), caused by Sclerotinia sclerotiorum (Lib.) de Bary, is a widespread disease of dry and green bean (Phaseolus vulgaris L.) in North America. Gamete selection (GS) was effective to combine and pyramide resistant genes and quantitative trait loci (QTL) for common bacterial blight. Our objective was to determine the effectiveness of GS to introgress physiological resistance to white mold. Two inter-gene-pool double-cross populations were developed. Selection for WM resistance was practiced from F1 to F4. Thirteen selected F1:5 breeding lines of each population and their four parents were evaluated. Two separate inoculations were made on each plant 1 week apart using a cut-stem method. The WM reaction was scored at 16, 23, and 33 days post inoculation (DPI) using a scale from 1 (no disease) to 9 (severely diseased or dead). In F1, 52% of Pop I (USPT-WM-1/CORN 601//USPT-CBB-1/92BG-7) and 67% of Pop II (Chase/I9365-25//ABL 15/A 195) susceptible plants were discarded. In F4, only 1.2% of families from Pop I, and 0.9% for Pop II, survived the selection process. An average of 20.5% gain in WM resistance was obtained for both populations in F4. Four breeding lines of Pop I had significantly (P = 0.05) lower WM score (4.1–4.6) and four were equal (4.7–4.9) to the best WM-resistant parent 92BG-7 (4.9), while ten breeding lines of Pop II were equal (4.5–4.8) to the best WM-resistant parent A 195 (4.6). Thus, GS was effective for improving WM resistance in common bean.

Impact of flower age and colour on infection of bean and alfalfa by Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is the causal agent of white mold of common bean (Phaseolus vulgaris) and blossom blight of alfalfa (Medicago sativa). No resistant cultivars of bean and alfalfa are currently available to growers in Canada. Studying physiological resistance is an important first step toward assessing and developing resistance in commercial cultivars. Flowers are generally the first tissue to be colonized by S. sclerotiorum in bean and alfalfa, and petal age has recently been shown to affect infection by S. sclerotiorum in canola (Brassica napus). Therefore, the development of the pathogen on detached flowers of bean and alfalfa was examined, focusing on the impact of flower colour and age on ascospore germination and mycelial growth. The colour and age of bean flowers did not affect ascospore germination or mycelial growth. Germtube growth was faster in extracts of 1-day-old petals than in extracts of 7-day-old petals for some cultivars. Petal extracts of bean had no inhibitory effect on ascospore germination and fungal growth, regardless of petal age and colour. Coloured flowers (purple or yellow) of alfalfa were colonized more slowly than white flowers. There was no difference in ascospore germination or mycelial growth in aqueous extracts from alfalfa petals of different colour, age or number. Petal age and colour did not have a substantial effect on the germination and development of S. sclerotiorum in alfalfa and bean.

Marker-assisted selection for white mold resistance in common bean

A marker-assisted selection (MAS) study was conducted on two recombinant inbred line (RIL) populations of common bean (Phaseolus vulgaris) to test the effectiveness of MAS for resistance to white mold (Sclerotinia sclerotiorum). Markers for quantitative trait loci (QTL) on linkage groups B2 and B7 that were previously associated with resistance and plant architectural avoidance traits in the resistant parent Bunsi were chosen. In the Bunsi/Midland population 10 RILs included in the MAS selected group developed significantly less disease than the control group based on two years of field evaluation under white mold pressure. Growth habit had no significant effect on disease severity or incidence. In the Bunsi/Raven RIL population, disease scores in the MAS selected group were significantly lower than scores in the control group over two years. Additional progress in enhancing resistance to white mold was detected when yield and plant architecture were included in the selection process. Lower disease scores among RILs were observed when comparisons were made to RILs selected using MAS alone. Yield is an important trait that should be considered when selecting for resistance to white mold. Finally the potential of Bunsi as a genetic donor of QTL for white mold resistance was confirmed in both populations studied. This study supported the effectiveness of MAS to enhance selection for a complexly inherited trait such as resistance to white mold in common bean.

Identification of QTL Associated with White Mold Resistance in Common Bean

White mold, caused by the necrotrophic fungusSclerotinia sclerotiorum(Lib.) de Bary, is a serious disease of common bean (Phaseolus vulgarisL.). The use of resistant cultivars is the preferred control strategy, but the approach has been difficult to implement because of quantitative nature of genetic resistance to white mold. The objectives of this study were to identify quantitative trait loci (QTL) associated with resistance toS. sclerotiorum, identify QTL associated with agronomic traits that contribute to white mold avoidance, and locate putative QTL on the integrated bean map. Bulked segregant analysis using multiple trait bulks that included disease severity index (DSI), yield, and days to flower was used to detect QTL associated with field resistance to white mold in a Middle American recombinant inbred line (RIL) population of common bean. QTL that accounted for 9.2 to 14.7% of the phenotypic variation for DSI were located on linkage groups B2, B5, B7, and B8 of the integrated bean map. In addition, QTL were detected for seed size and yield and agronomic traits associated with disease avoidance: days to maturity, days to flower, and lodging. Heritability estimates for DSI were moderate (0.41) and correlations with agronomic traits that included lodging (0.56**), architecture (0.35**), canopy height (−0.33**), and yield (−0.64**) support the importance of these traits in disease avoidance. Data from the current study provides breeders with critical information on which traits and genomic regions to target as part of an overall strategy to enhance resistance to white mold in common bean.

QTL Conferring Resistance and Avoidance to White Mold in Common Bean

White mold, caused by Sclerotinia sclerotiorum (Lib.) De Bary, is a serious fungal disease that negatively affects production of common bean (Phaseolus vulgaris L.). Resistance to white mold in common bean is complexly inherited and comprised of physiological resistance and avoidance mechanisms. The objectives of this research were to discover quantitative trait loci (QTL) conferring resistance to white mold in navy beans, to determine if a multitrait bulking strategy was an efficient approach for locating QTL conferring resistance to white mold, and to identify agronomic traits associated with QTL for white mold avoidance in the field. A 98 F 3 -derived Bunsi/Newport population was evaluated in three environments for resistance to white mold and agronomic traits. A 28 recombinant inbred line population derived from a Huron/Newport cross was evaluated for the resistance and yield in four environments and was used to confirm marker associations. Marker BC20.1800 on B2 was associated with disease severity index (DSI) (12%) across environments, and was confirmed in the second population. Markers linked to QTL were also detected on B7 for DSI (17%), resistance to oxalate (16%), yield (37%), as well as days to flowering (14%), branching pattern (9%), lodging (9%) and seed size (20%). Growth habit unexpectedly mapped to B7, and represents a novel source of determinacy in navy bean. Multiple-trait bulking based on low DSI, high yield, and 40 to 45 d to flowering versus high DSI, low yield, and 40 to 45 d to flowering effectively identified more markers linked to QTL for resistance to white mold than did bulks based on low and high DSI alone. Selection based on QTL that confer resistance to white mold, such as the Bunsi-derived QTL located on B2 and B7 of the bean genome, combined with certain desirable agronomic traits offers the opportunity to develop resistant cultivars and improve our understanding of resistance to white mold in common bean.

QTL Conferring Resistance and Avoidance to White Mold in Common Bean

QTL Conferring Resistance and Avoidance to White Mold in Common Bean

Agronomic Traits Affecting Resistance to White Mold in Common Bean

Resistance to white mold [caused by Sclerotinia sclerotiorum (Lib.) de Bary] in common bean (Phaseolus vulgaris L.) is complexly inherited, and highly influenced by environmental factors. The identification of agronomically desirable avoidance mechanisms in advanced or elite lines and segregating populations is essential. The objectives of this study were to determine the relationship between nine agronomic traits (growth habit, days to flower, canopy height and width, branching pattern, lodging, days to maturity, seed size, and yield) and resistance to white mold in the field, corresponding heritabilities of resistance and agronomic traits, and the effect of the agronomic traits on disease and seed yield. A group of elite lines, and two recombinant populations derived from crosses between two resistant navy bean cultivars, Bunsi and Huron, to a susceptible cultivar, Newport, were evaluated for disease severity index (DSI) and agronomic traits in multiple field seasons. Heritability estimates for DSI were moderate (0.47) in the Bunsi/Newport population and high (0.82) in the Huron/Newport population. All agronomic traits displayed moderate to high heritability estimates. The agronomic traits that associated significantly with DSI in the three populations differed greatly. The most important agronomic trait that reduced DSI and contributed to yield was indeterminate growth habit. Increased canopy height, width, and lodging were generally associated with an increase in DSI, whereas traits such as days to flower and maturity varied in relation to DSI and yield across environments and populations. The complexity of the relationship of agronomic traits to DSI and yield highlights the difficulties bean breeders face in selecting among elite lines and within segregating populations for resistance to white mold in the field.