Effectiveness of Moringa oleifera (Lam) Extracts against Sclerotinia sclerotorium (Lib) De Bary, the Causative Agent of White Mold  of Common Bean (Phaseolus vulgaris L.)

Abstract Background White mold (WM) is a major disease in common bean ( Phaseolus vulgaris L.), and its complex quantitative genetic control has limited the development of WM resistant cultivars. WM2.2 is one of the nine meta-QTL that has a major effect on WM tolerance. This QTL explains up to 35% of the phenotypic variation and was previously mapped to a large interval on Pv02. Our objective was to narrow the interval of this QTL using QTL-based bulk segregant analysis.Results The phenotypic and genotypic data from two RIL populations (R31 and Z0726-9), which possess different genetic backgrounds for white mold resistance, were used to select resistant and susceptible lines to generate subpopulations for bulk DNA sequencing, and reads were aligned against the sequence of the resistance parent. The QTL physical intervals for each RIL population were mapped by fixed SNPs in 10kb-2kb sliding windows. WM2.2 QTL was split into two regions WM2.2a (3.54-4.56 Mbp; euchromatic) and WM 2.2b (12.19 to 26.41 Mbp; heterochromatic) in populations R31 and Z0726-9, respectively. For each QTL interval, the possible functional contribution of significant non-synonymous and synonymous polymorphisms was investigated. Gene models encoding for pentatricopeptide repeat, gibberellin 2-oxidase, and heat-shock proteins are the likely candidate genes associated with WM2.2a resistance. A TIR-NBS-LRR class of disease resistance protein and a EF-TU receptor are potential candidate genes associated with WM2.2b resistance and most likely trigger a physiological resistance response to WM.Conclusion QTL-based pooled sequencing analysis revealed that the large genomic region associated with WM2.2 meta QTL consists of two major QTL each associated with a different WM resistance function. WM2.2a region is most likely associated with avoidance mechanisms while WM2.2b region triggers physiological resistance.

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

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v21n10p691-696 ◽

2017 ◽

Vol 21 (10) ◽

pp. 691-696 ◽

Cited By ~ 1

Author(s):

David R. P. Montes ◽

Rubens A. Oliveira ◽

Luan B. Giovanelli ◽

Reginaldo M. de Oliveira ◽

Júlio C. M. Baptestini ◽

...

Keyword(s):

Statistical Analysis ◽

Phaseolus Vulgaris ◽

Common Bean ◽

Block Design ◽

White Mold ◽

Phaseolus Vulgaris L ◽

Main Method ◽

Randomized Block Design ◽

Cultivation Practices ◽

Favorable Conditions

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.

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