Evaluation efficiency of severity of angular leaf spot in common bean based on diseased and healthy leaf area

This study compared severity of angular leaf spot in common bean lines, based on the healthy and diseased leaf area, and the graded scale. We used 12 common bean lines in the dry and rainy seasons. Two contiguous experiments were conducted in each season, with and without chemical control of the pathogen. We evaluated the percentage of the healthy and diseased leaf area; severity based on a graded scale and the area under the disease progress curve; and yield. The diseased or healthy leaf area is efficient to evaluate the severity of angular leaf spot with a sample of 20 to 30 leaflets per plot. For all traits, the results of central and border areas did not differ, indicating that the evaluation of border rows is unnecessary and, finally, the severity assessment of the upper plant half can discriminate the lines more efficiently.

Download Full-text

Effects of Angular Leaf Spot and Rust on Yield Loss of Phaseolus vulgaris

Phytopathology ◽

10.1094/phyto.2001.91.11.1045 ◽

2001 ◽

Vol 91 (11) ◽

pp. 1045-1053 ◽

Cited By ~ 56

Author(s):

W. C. de Jesus ◽

F. X. R. do Vale ◽

R. R. Coelho ◽

B. Hau ◽

L. Zambolim ◽

...

Keyword(s):

Phaseolus Vulgaris ◽

Leaf Area ◽

Leaf Spot ◽

Field Experiments ◽

Angular Leaf Spot ◽

Growth And Yield ◽

Control Treatment ◽

Healthy Leaf ◽

Progress Curve ◽

Host Growth

Three field experiments were conducted in 1997, 1998, and 1999 to investigate the effects of angular leaf spot and rust, separately or combined, on host growth and yield of individual bean plants (Phaseolus vulgaris). In each experiment, three treatments were established by inoculating cv. Carioca with Phaeoisariopsis griseola, Uromyces appendiculatus, or with both pathogens. An additional control treatment was not inoculated, but was sprayed with a fungicide. In the 1997 and 1999 experiments, angular leaf spot reached higher disease levels than rust, whereas in 1998, rust was more severe than angular leaf spot. Host growth, expressed as healthy leaf area duration (HAD), and yield were the highest in 1997 and lowest in 1998. In each experiment, the treatments did not differ significantly to the area under leaf area progress curve, HAD, and healthy leaf area absorption (HAA). All inoculated treatments had significantly more severe disease and less yield than the control treatment. Based on the analysis of 60 plants in each experiment, yield was not related to the areas under disease progress curve for either or both diseases. In 1997 and 1999, yield was related to HAD (R2 = 0.57 and 0.43) and HAA(R2 = 0.60 and 0.55). Based on the combined analysis of all 36 plots, angular leaf spot reduced the leaf area because of defoliation, whereas rust did not affect the leaf area. Rust reduced yield more than four times that of angular leaf spot, although the decrease in photosynthesis to angular leaf spot was twice that of rust.

Download Full-text

Field Characterization of Partial Resistance to Gray Leaf Spot in Elite Maize Germplasm

Phytopathology ◽

10.1094/phyto-12-19-0446-r ◽

2020 ◽

Vol 110 (10) ◽

pp. 1668-1679

Author(s):

James O. Nyanapah ◽

Patrick O. Ayiecho ◽

Julius O. Nyabundi ◽

Washington Otieno ◽

Peter S. Ojiambo

Keyword(s):

Disease Resistance ◽

Leaf Area ◽

Plant Development ◽

Leaf Spot ◽

Partial Resistance ◽

Inflection Point ◽

Inbred Lines ◽

Gray Leaf Spot ◽

Diseased Leaf ◽

Diseased Leaf Area

Forty-eight inbred lines of maize with varying levels of resistance to gray leaf spot (GLS) were artificially inoculated with Cercospora zeina and evaluated to characterize partial disease resistance in maize under field conditions from 2012 to 2014 across 12 environments in western Kenya. Eight measures of disease epidemic—that is, final percent diseased leaf area (FPDLA), standardized area under the disease progress curve (SAUDPC), weighted mean absolute rate of disease increase (ρ), disease severity scale (CDSG), percent diseased leaf area at the inflection point (PDLAIP), SAUDPC at the inflection point (SAUDPCIP), time from inoculation to transition of disease progress from the increasing to the decreasing phase of epidemic increase (TIP), and latent period (LP)—were examined. Inbred lines significantly (P < 0.05) affected all measures of disease epidemic except ρ. However, the proportion of the variation attributed to the analysis of variance model was most strongly associated with SAUDPC (R2 = 89.4%). Inbred lines were also most consistently ranked for disease resistance based on SAUDPC. Although SAUDPC was deemed the most useful variable for quantifying partial resistance in the test genotypes, the proportion of the variation in SAUDPC in each plot was most strongly (R2 = 93.9%) explained by disease ratings taken between the VT and R4 stages of plant development. Individual disease ratings at the R4 stage of plant development were nearly as effective as SAUDPC in discerning the differential reaction of test genotypes. Thus, GLS rankings of inbred lines based on disease ratings at these plant developmental stages should be useful in prebreeding nurseries and preliminary evaluation trials involving large germplasm populations.

Download Full-text

Inheritance and development of molecular markers linked to angular leaf spot resistance genes in the common bean accession G10909

Molecular Breeding ◽

10.1007/s11032-010-9461-x ◽

2010 ◽

Vol 28 (1) ◽

pp. 57-71 ◽

Cited By ~ 17

Author(s):

George S. Mahuku ◽

María Antonia Henríquez ◽

Carmenza Montoya ◽

Carlos Jara ◽

Henry Teran ◽

...

Keyword(s):

Molecular Markers ◽

Common Bean ◽

Resistance Genes ◽

Leaf Spot ◽

Angular Leaf Spot ◽

The Common

Download Full-text

Response of Ugandan common bean varieties to Pseudocercospora griseola and Angular leaf spot disease development in varietal mixtures

International Journal of Pest Management ◽

10.1080/09670874.2016.1234656 ◽

2016 ◽

Vol 63 (2) ◽

pp. 119-127 ◽

Cited By ~ 3

Author(s):

N. Olango ◽

G. Tusiime ◽

J.W. Mulumba ◽

R. Nankya ◽

C. Fadda ◽

...

Keyword(s):

Common Bean ◽

Leaf Spot ◽

Angular Leaf Spot ◽

Leaf Spot Disease ◽

Disease Development ◽

Spot Disease ◽

Pseudocercospora Griseola

Download Full-text

Genetic characterization of angular leaf spot resistance in selected common bean landraces from Tanzania

AFRICAN JOURNAL OF BIOTECHNOLOGY ◽

10.5897/ajb2014.14056 ◽

2015 ◽

Vol 14 (43) ◽

pp. 2943-2948 ◽

Cited By ~ 1

Author(s):

Muhamba Tryphone George ◽

Amos Chilagane Luseko ◽

Nchimbi Msolla Susan ◽

Mbogo Kusolwa Paul

Keyword(s):

Common Bean ◽

Leaf Spot ◽

Genetic Characterization ◽

Angular Leaf Spot

Download Full-text

Characterization of the common bean host and Pseudocercospora griseola, the causative agent of angular leaf spot disease in Tanzania

African Journal of Plant Science ◽

10.5897/ajps2016.1427 ◽

2016 ◽

Vol 10 (11) ◽

pp. 238-245 ◽

Cited By ~ 1

Author(s):

Amos Chilagane Luseko ◽

Nchimbi-Msolla Susan ◽

Mbogo Kusolwa Paul ◽

Gabriel Porch Timothy ◽

Miryam Serrato Diaz Luz ◽

...

Keyword(s):

Common Bean ◽

Causative Agent ◽

Leaf Spot ◽

Angular Leaf Spot ◽

Leaf Spot Disease ◽

Spot Disease ◽

The Common ◽

Pseudocercospora Griseola

Download Full-text

Identification of Phaeoisariopsis griseola pathotypes from five States in Brazil

Fitopatologia Brasileira ◽

10.1590/s0100-41582002000100012 ◽

2002 ◽

Vol 27 (1) ◽

pp. 78-81 ◽

Cited By ~ 19

Author(s):

ALOISIO SARTORATO

Keyword(s):

Phaseolus Vulgaris ◽

Common Bean ◽

Resistance Genes ◽

Leaf Spot ◽

Angular Leaf Spot ◽

Phaeoisariopsis Griseola ◽

Moist Chamber ◽

Differential Cultivars ◽

Pathogenic Variability ◽

Resistant Genotypes

Due to the increased importance of angular leaf spot of common bean (Phaseolus vulgaris) in Brazil, monitoring the pathogenic variability of its causal agent (Phaeoisariopsis griseola) is the best strategy for a breeding program aimed at developing resistant genotypes. Fifty one isolates of P. griseola collected in five Brazilian States were tested on a set of 12 international differential cultivars in the greenhouse. When inoculated plants showed symptoms but no sporulation was observed, they were transferred to a moist chamber for approximately 20-24 h. After this period of time, if no sporulation was observed, the plants were considered resistant; otherwise, they were considered susceptible. From the fifty-one tested isolates, seven different pathotypes were identified. No Andean pathotypes were identified; consequently, all isolates were classified as Middle American pathotypes. Pathotype 63-31 was the most widespread. Pathotype 63-63 overcame resistance genes present in all differential cultivars and also the resistance gene(s) present in the cultivar AND 277. This fact has important implications for breeding angular leaf spot resistance in beans, and suggests that searching for new resistance genes to angular leaf spot must be pursued.

Download Full-text