Pinolide, a New Nonenolide Produced by Didymella pinodes, the Causal Agent of Ascochyta Blight on Pisum sativum

2012 ◽  
Vol 60 (21) ◽  
pp. 5273-5278 ◽  
Author(s):  
Alessio Cimmino ◽  
Anna Andolfi ◽  
Sara Fondevilla ◽  
Mohamed A. Abouzeid ◽  
Diego Rubiales ◽  
...  
Keyword(s):  
Pisum Sativum ◽  
Ascochyta Blight ◽  
Causal Agent ◽  
Didymella Pinodes

scholarly journals Relative Host Resistance to Black Spot Disease in Field Pea (Pisum sativum) is Determined by Individual Pathogens

Plant Disease ◽  
2015 ◽  
Vol 99 (5) ◽  
pp. 580-587 ◽  
Author(s):  
Hieu Sy Tran ◽  
Ming Pei You ◽  
Tanveer N. Khan ◽  
Martin J. Barbetti
Keyword(s):  
Pisum Sativum ◽  
Host Resistance ◽  
Ascochyta Blight ◽  
Black Spot ◽  
Field Pea ◽  
Breeding Programs ◽  
Didymella Pinodes ◽  
Progress Curve ◽  
The Individual ◽  
Important Disease

Black spot, also known as Ascochyta blight, is the most important disease on field pea (Pisum sativum). It is caused by a complex of pathogens, the most important of which in Australia include Didymella pinodes, Phoma pinodella, and P. koolunga. The relative proportions of these and other component pathogens of the complex fluctuate widely across time and geographic locations in Australia, limiting the ability of breeders to develop varieties with effective resistance to black spot. To address this, 40 field pea genotypes were tested under controlled environment conditions for their individual stem and leaf responses against these three pathogens. Disease severity was calculated as area under disease progress curve (AUDPC), and subsequently converted to mean rank (MR). The overall rank (OR) for each pathogen was used to compare response of genotypes under inoculation with each pathogen. The expressions of host resistance across the field pea genotypes were largely dependent upon the individual test pathogen and whether the test was on stem or leaf. Overall, P. koolunga caused most severe stem disease; significantly more severe than either D. pinodes or P. pinodella. This is the first report of the host resistance identified in field pea to P. koolunga; the five genotypes showing highest resistance on stem, viz. 05P778-BSR-701, ATC 5338, ATC 5345, Dundale, and ATC 866, had AUDPC MR values <250.4, while the AUDPC MR values of the 19 genotypes showing the best resistance on leaf was less than 296.8. Two genotypes, ATC 866 and Dundale, showed resistance against P. koolunga on both stem and leaf. Against D. pinodes, the four and 16 most resistant genotypes on stem and leaf had AUDPC MR values <111.2 and <136.6, respectively, with four genotypes showing resistance on both stem and leaf including 05P770-BSR-705, Austrian Winter Pea, 06P822-(F5)-BSR-6, and 98107-62E. Against P. pinodella, four and eight genotypes showing the best resistance on stem and leaf had AUDPC MR values <81.3 and <221.9, respectively; three genotypes, viz. 98107-62E, Dundale, and Austrian Winter Pea showed combined resistance on stem and leaf. A few genotypes identified with resistance against two major pathogens of the complex will be of particular significance to breeding programs. These findings explain why field pea varieties arising from breeding programs in Australia fail to display the level or consistency of resistance required against black spot and why there needs to be a wider focus than D. pinodes in breeding programs.

Importance of seed-borne inoculum in the etiology of the Ascochyta blight complex of field peas (Pisum sativum L.) grown in Victoria

1995 ◽  
Vol 35 (4) ◽  
pp. 525 ◽  
Author(s):  
TW Bretag ◽  
TV Price ◽  
PJ Keane
Keyword(s):  
Pisum Sativum ◽  
Ascochyta Blight ◽  
Mycosphaerella Pinodes ◽  
Seed Infection ◽  
Seeding Rate ◽  
Pisum Sativum L ◽  
Field Peas ◽  
Ascochyta Pisi ◽  
Growing Region ◽  
Seed Infestation

Fungi associated with the ascochyta blight complex of field peas were isolated from 436 of 691 seedlots tested. Of the fungi detected, 94.8% of isolates were Mycosphaerella pinodes, 4.2% Phoma medicaginis, and 1.0% Ascochyta pisi. The levels of infestation of seed varied considerably from year to year and between seedlots, depending on the amount of rainfall between flowering and maturity. Within a particular pea-growing region, the level of seed-borne infection was often highest in seed from crops harvested latest. In addition, crops sown early were usually more severely affected by disease than late-sown crops, and this resulted in higher levels of seed infection. There was no correlation between the level of seed infestation by M. pinodes and the severity of ascochyta blight; however, where the level of seed infection was high (>11%) there was a significant reduction in emergence, which caused a reduction in grain yield. It may therefore be possible to use seed with high levels of seed-borne ascochyta blight fungi, provided the seeding rate is increased to compensate for poor emergence.

scholarly journals Aggressiveness Changes in Populations of Didymella pinodes over Winter and Spring Pea Cropping Seasons

2016 ◽  
Vol 82 (14) ◽  
pp. 4330-4339 ◽  
Author(s):  
G. Laloi ◽  
J. Montarry ◽  
M. Guibert ◽  
D. Andrivon ◽  
D. Michot ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Ascochyta Blight ◽  
Growing Season ◽  
Climatic Conditions ◽  
Single Population ◽  
High Genetic Diversity ◽  
Content Type ◽  
Didymella Pinodes ◽  
Pathogenicity Tests ◽  
Cropping Seasons

ABSTRACTAscochyta blight, caused by the necrotrophic ascomyceteDidymella pinodes, is responsible for severe losses in winter and spring pea crops. Despite different climatic conditions, epidemics on winter and spring crops are due to a single population ofD. pinodes, suggesting gene flow either between the two crops or from reservoir sources during the cropping season. This should lead to similar pathogenicity characteristics in isolates sampled from the two crops. However, these hypotheses have never been formally tested. We therefore sampled a total of 520D. pinodesstrains throughout a growing season from winter and spring pea plots (WP and SP, respectively) and from winter and spring trap plants (TWP and TSP). Amplified fragment length polymorphism (AFLP) markers revealed high genetic diversity within subpopulations, whereas pathogenicity tests showed that mean aggressiveness increases over the course of an epidemic. These results support the idea that alloinoculum contributes to the carryover of epidemics between winter and spring crops and that the most aggressive isolates are selected as an epidemic progresses.IMPORTANCEAscochyta blight, caused byDidymella pinodes, is responsible for severe losses in pea crops. While previous studies have shown that ascochyta blight epidemics on winter and spring crops are due to a single population ofD. pinodes, suggesting that isolates from the two crops present similar pathogenicity characteristics, that hypothesis have never been tested. Genetic analysis of subpopulations sampled throughout a growing season from winter and spring pea plots revealed high genetic diversity within subpopulations, whereas pathogenicity tests showed that mean aggressiveness increases over the course of an epidemic.

Variation in pathogenicity among and within Mycosphaerella pinodes populations collected from field pea in Australia

1998 ◽  
Vol 76 (11) ◽  
pp. 1955-1966 ◽  
Author(s):  
J M Wroth
Keyword(s):  
Cluster Analysis ◽  
Pisum Sativum ◽  
Host Resistance ◽  
Ascochyta Blight ◽  
Mycosphaerella Pinodes ◽  
Environment Interaction ◽  
Pathogen Population ◽  
Host Genotype ◽  
Host Pathogen Interaction ◽  
The Relationship

Ninety-nine single ascospore isolates of Mycosphaerella pinodes (Berk. & Blox.) Vestergr. from widely separated locations in southern Australia varied greatly in their ability to cause disease in leaves and stems of 10 host genotypes when assayed at two inoculum pressures. There were highly significant differences between the infection pressures, isolates, and host genotypes that accounted for most of the variance. A small proportion of the variance included a highly significant host genotype beta isolate interactions in leaves and stems and a highly significant host genotype beta isolate beta environment interaction in leaves. The continuous variation in disease responses among isolates precluded classification into distinct pathotypes. A cluster analysis of the data revealed that many isolates were closely related irrespective of the host cultivar or location from which they were collected. The relationship between mean host resistance and the variation among isolates was assessed, and it was concluded that increasing host resistance was unlikely to increase variation in the pathogen population; therefore, resistance should be relatively stable.Key words: Ascochyta blight, Pisum sativum, host-pathogen interaction, cluster analysis.

Lentisone, a New Phytotoxic Anthraquinone Produced by Ascochyta lentis, the Causal Agent of Ascochyta Blight in Lens culinaris

2013 ◽  
Vol 61 (30) ◽  
pp. 7301-7308 ◽  
Author(s):  
Anna Andolfi ◽  
Alessio Cimmino ◽  
Angel M. Villegas-Fernández ◽  
Angela Tuzi ◽  
Antonello Santini ◽  
...  
Keyword(s):  
Lens Culinaris ◽  
Ascochyta Blight ◽  
Causal Agent ◽  
Ascochyta Lentis

Fungicidal control of ascochyta blight of field pea

1996 ◽  
Vol 76 (1) ◽  
pp. 67-71 ◽  
Author(s):  
T. D. Warkentin ◽  
K. Y. Rashid ◽  
A. G. Xue
Keyword(s):  
Pisum Sativum ◽  
Key Words ◽  
Untreated Control ◽  
Seed Weight ◽  
Ascochyta Blight ◽  
Field Pea ◽  
Mycosphaerella Pinodes ◽  
Yield Increase ◽  
Pisum Sativum L

The use of fungicides for the control of ascochyta blight in field pea was investigated. Four fungicides were applied to the cultivars AC Tamor and Radley at two locations in Manitoba in 1993 and 1994. Fungicides were applied either once, twice, or three times at 10-d intervals, beginning at the initiation of flowering. Chlorothalonil and benomyl were effective m reducing the severity of ascochyta blight and increasing the yield and seed weight of field pea. The triple application of chlorothalonil resulted in a mean yield increase of 33% over that of the untreated control. Iprodione and propiconazole were relatively ineffective in controlling ascochyta blight. The percentage of seedborne ascochyta was not significantly affected by fungicide treatments. The severity of ascochyta blight was greater in 1993 that in 1994, resulting in greater benefits of chlorothalonil and benomyl applications in 1993. Key words: Field pea, Pisum sativum L., ascochyta blight, Mycosphaerella pinodes, fungicide

Sign in / Sign up

Export Citation Format

Share Document