New Races in Parameterized Algorithmics

Anthracnose, caused by the fungus Colletotrichum lindemuthianum (Sacc. & Magnus) Briosi & Cavara, is one of the most destructive diseases of dry bean (Phaseolus vulgaris L.) in the world. Between 2005 and 2015, commercial fields of dry beans in Manitoba and Ontario were surveyed to determine the frequency of occurrence of races of the anthracnose fungus. Throughout the study, race 73 was most prevalent in Manitoba and Ontario. However, three anthracnose races not previously reported in Canada also were identified. These three new races and four previously identified anthracnose races were used to screen 52 dry bean cultivars, as well as a mung bean and azuki bean cultivar from Ontario, for their seedling reactions to determine their patterns of race resistance. The dry bean cultivars were classified into a total of 19 resistance spectra based on the pattern of seedling reactions to the seven anthracnose races. The most common resistance spectrum was susceptible to the majority of the anthracnose races and no cultivar was resistant to all of the races. Many bean cultivars produced intermediate anthracnose ratings to races 31 and 105 and tests of 16 dry bean cultivars against those races indicated that all cultivars with intermediate ratings to a specific race were segregating in their seedling reactions and none of the cultivars produced plants with only intermediate anthracnose severity ratings. This study provides new information on the anthracnose reactions of common bean cultivars in Canada, which should be useful for the development of new bean cultivars with durable resistance.

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Genetic dissection of partial resistance to race 6 of Venturia inaequalis in apple

Genome ◽

10.1139/g02-127 ◽

2003 ◽

Vol 46 (2) ◽

pp. 224-234 ◽

Cited By ~ 60

Author(s):

C E Durel ◽

L Parisi ◽

F Laurens ◽

W E Van de Weg ◽

R Liebhard ◽

...

Keyword(s):

Resistance Gene ◽

Malus Domestica ◽

Quantitative Trait ◽

Partial Resistance ◽

Venturia Inaequalis ◽

Genetic Dissection ◽

Resistance Breakdown ◽

Trait Locus ◽

New Races ◽

Genomic Regions

Scab, caused by the fungus Venturia inaequalis, is one of the most important diseases of apple (Malus × domestica). The major resistance gene, Vf, has been widely used in apple breeding programs, but two new races of the fungus (races 6 and 7) are able to overcome this gene. A mapped F1 progeny derived from a cross between the cultivars Prima and Fiesta has been inoculated with two monoconidial strains of race 6. These strains originated from sporulating leaves of 'Prima' and a descendant of 'Prima' that were grown in an orchard in northern Germany. 'Prima' carries the Vf resistance gene, whereas 'Fiesta' lacks Vf. A large variation in resistance and (or) susceptibility was observed among the individuals of the progeny. Several quantitative trait loci (QTLs) for resistance were identified that mapped on four genomic regions. One of them was located in the very close vicinity of the Vf resistance gene on linkage group LG-1 of the 'Prima' genetic map. This QTL is isolate specific because it was only detected with one of the two isolates. Two out of the three other genomic regions were identified with both isolates (LG-11 and LG-17). On LG-11, a QTL effect was detected in both parents. The genetic dissection of this QTL indicated a favourable intra-locus interaction between some parental alleles.Key words: Malus × domestica, partial resistance, Venturia inaequalis, resistance breakdown, quantitative trait locus.

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XV.—Three new races of Cephalophus monticola

Annals and Magazine of Natural History ◽

10.1080/00222932208632653 ◽

1922 ◽

Vol 9 (50) ◽

pp. 174-176

Author(s):

Gilbert Blaine

Keyword(s):

Cephalophus Monticola ◽

New Races

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Two-Layer Planarization: Improving on Parameterized Algorithmics

Journal of Graph Algorithms and Applications ◽

10.7155/jgaa.00106 ◽

2005 ◽

Vol 9 (2) ◽

pp. 205-238 ◽

Cited By ~ 16

Author(s):

Henning Fernau

Keyword(s):

Parameterized Algorithmics

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Parameterized Algorithmics for Finding Exact Solutions of NP-Hard Biological Problems

Methods in Molecular Biology - Bioinformatics ◽

10.1007/978-1-4939-6613-4_20 ◽

2016 ◽

pp. 363-402 ◽

Cited By ~ 1

Author(s):

Falk Hüffner ◽

Christian Komusiewicz ◽

Rolf Niedermeier ◽

Sebastian Wernicke

Keyword(s):

Exact Solutions ◽

Np Hard ◽

Parameterized Algorithmics

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Twin-Cover: Beyond Vertex Cover in Parameterized Algorithmics

Parameterized and Exact Computation - Lecture Notes in Computer Science ◽

10.1007/978-3-642-28050-4_21 ◽

2012 ◽

pp. 259-271 ◽

Cited By ~ 17

Author(s):

Robert Ganian

Keyword(s):

Vertex Cover ◽

Parameterized Algorithmics

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Pathogenic Specialization of Venturia nashicola, Causal Agent of Asian Pear Scab, and Resistance of Pear Cultivars Kinchaku and Xiangli

Phytopathology ◽

10.1094/phyto-06-20-0220-r ◽

2020 ◽

Author(s):

Hideo Ishii ◽

Kumiko Nishimura ◽

Kenji Tanabe ◽

Yuichi Yamaoka

Keyword(s):

Resistance Breeding ◽

Scab Resistance ◽

Japanese Pear ◽

Pyrus Pyrifolia ◽

Asian Pear ◽

Sexual Recombination ◽

Venturia Nashicola ◽

Race 1 ◽

New Races ◽

Race 2

Scab, caused by Venturia nashicola is one of the most serious diseases of Asian pears including Japanese pear (Pyrus pyrifolia var. culta) and Chinese pears (P. bretschneideri and P. ussuriensis). Breeding of scab-resistant pear cultivars is essential to minimize the use of fungicides and the risk of fungicide resistance developing in the pathogen. A survey of pathogenic specialization in V. nashicola is needed to ensure durable scab resistance in cultivated pears. Race 1, 2, and 3 isolates of V. nashicola, each differing in pathogenicity to Japanese pear cv. Kousui and Asian pear strain Mamenashi 12, have been reported from Japan. In the present study, isolates collected from scabbed pears in China and Taiwan were classified as V. nashicola based on conidial size and mating ability. However, various isolates were found to have pathogenicity distinct from races 1, 2, and 3 in tests on seven differential host genotypes: Kousui; Mamenashi 12; Chinese pear cvs. Jingbaili, Yali, Linyuli, Nanguoli; and Taiwanese pear cv. Hengshanli. The new races were designated as races 4 to 7. Progenies characteristic of race 3 isolates were produced in a cross between race 1 and race 2 isolates, suggesting the possible role of sexual recombination in the emergence of novel races. Japanese pear cv. Kinchaku and cv. Xiangli of P. sinkiangensis (Korla fragrant pear grown in China) didn’t show visible symptoms after inoculation with any of the seven races. The broad scab resistance in Kinchaku and Xiangli makes them a promising genetic resource for resistance breeding programs.

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