Quantitative Resistance to witches’ broom disease in progenies of different sources of resistance.

The witches' broom disease caused by the fungus Crinipellis perniciosa is the main phytossanitary constraint for cacao production in Brazil. The integrated management of the disease involves resistance as one of the components. The breeding program conducted by the Brazilian Institution, CEPLAC is directed toward the pyramidation of resistance genes from different sources to achieve a more durable resistance. This study aimed to identify sources of resistance in progenies of cacao accessions collected in the basins of ten Amazonian rivers and compared to progenies from the Peruvian clones 'Scavina 6' and 'Sacavina 12'. Progenies from 40 Amazonian accessions and 'Scavina' were evaluated in the field for six years for witches' broom resistance through multivariate and repeated measurement analyses evaluating the effect of progeny, area, block, year, and their interactions. There were differences in the mean number of vegetative brooms on some Amazonian progenies and 'Scavina' descendants. There was an increase in the number of vegetative brooms in the last year for 'Scavina' progenies, but that was not observed for the Amazonian progenies 64, 66, 156, 194, 195, 269 and 274. There were different gene/alleles for resistance in the Amazonian progenies in comparison to the traditional 'Scavina' accessions. These new sources of resistance will be important for pyramiding resistance genes and consequently increasing the stability and durability of the resistance to witches' broom.

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Influence of Soybean Cropping Sequences on Seed Yield and Female Index of the Soybean Cyst Nematode

Plant Disease ◽

10.1094/pdis.1998.82.6.615 ◽

1998 ◽

Vol 82 (6) ◽

pp. 615-619 ◽

Cited By ~ 17

Author(s):

Lawrence D. Young

Keyword(s):

Soybean Cyst Nematode ◽

Cyst Nematode ◽

Resistant Cultivar ◽

Breeding Line ◽

Sources Of Resistance ◽

Resistant Cultivars ◽

Cropping Sequence ◽

Moderately Resistant ◽

Different Sources ◽

Female Index

Several soybean (Glycine max) cropping sequences were planted for 12 years in a field that, at the beginning of the test, was infested with race 14 of the soybean cyst nematode, Heterodera glycines. Continuous soybean cropping sequences included H. glycines-susceptible cultivars Forrest, J82-21, Peking × Centennial breeding line, and moderately resistant cultivars Bedford and J81-116. Forrest treated with aldicarb or pentachloronitrobenzene (PCNB) plus metalaxyl and resistant breeding line JS83-236 followed by resistant cultivars Cordell and Hartwig were additional continuous soybean sequences. Rotations included two sequences each of Bedford with J81-116 or J82-21, and three sequences of Bedford with corn (Zea mays) and susceptible Essex soybean. Rotations of Bedford, corn, and Essex had 12-year mean yields significantly greater than continuous Bedford or Forrest. The female index (FI) of H. glycines on five cultivars and lines was used to bioassay changes in parasitic potential in each cropping sequence. The FI on Bedford bioassay plants increased significantly over time for all field treatments involving Bedford. When J82-21 was the bioassay plant, FI decreased significantly in treatments involving Bedford. There were no significant changes in FI for any treatment when Forrest, J81-16, and Peking were used as bioassays. Rotations of soybean cultivars with different sources of resistance and rotations of resistant and susceptible cultivars with a nonhost crop were not successful practices to manage the nematode's ability to parasitize the resistant cultivar Bedford. However, rotation of resistant and susceptible cultivars with a nonhost crop produced greater mean soybean yields and slowed the shift toward greater parasitism of the resistant cultivar sufficiently to warrant adoption of this practice.

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Advances in understanding the epidemiology, molecular biology and control of net blotch and the net blotch barley interaction

10.19103/as.2021.0092.31 ◽

2021 ◽

pp. 477-524

Author(s):

Anke Martin ◽

◽

Barsha Poudel ◽

Buddhika Amarasinghe Dahanayaka ◽

Mark S. McLean ◽

...

Keyword(s):

Molecular Biology ◽

Fungicide Resistance ◽

Net Blotch ◽

Sources Of Resistance ◽

Breeding Programs ◽

Barley Cultivars ◽

Sexual And Asexual Reproduction ◽

And Control ◽

Different Sources ◽

Durable Disease Resistance

Net blotches are the most widely distributed foliar diseases of barley worldwide, causing significant losses in grain yield. They occur as net form net blotch, caused by Pyrenophora teres f. teres and spot form net blotch caused by P. teres f. maculata. Both sexual and asexual reproduction play a role in the P. teres disease cycles leading to changes in genetic variation of populations. Breeding programs have to keep pace with pathogenic changes and ensure different sources of resistance are present in current barley cultivars. Knowledge of the genetic architecture and genes involved in virulence is thus vital to increase the durability of net blotch resistance in barley cultivars. This chapter explores the molecular biology, life-cycle and epidemiology of the net blotch fungi and discusses the key challenges we are facing in managing the net blotches using both fungicide resistance and breeding strategies to achieve durable disease resistance in barley.

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Survival of Wheat Curl Mites on Different Sources of Resistance in Wheat

Crop Science ◽

10.2135/cropsci1999.3961887x ◽

1999 ◽

Vol 39 (6) ◽

pp. 1887-1889 ◽

Cited By ~ 39

Author(s):

T. L. Harvey ◽

D. L. Seifers ◽

T. J. Martin ◽

G. Brown-Guedira ◽

B. S. Gill

Keyword(s):

Sources Of Resistance ◽

Different Sources

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Dealing with resistance to the use of Industry 4.0 technologies in production disturbance management

Journal of Manufacturing Technology Management ◽

10.1108/jmtm-12-2020-0475 ◽

2021 ◽

Vol 32 (9) ◽

pp. 285-303

Author(s):

Adriana Ito ◽

Torbjörn Ylipää ◽

Per Gullander ◽

Jon Bokrantz ◽

Victor Centerholt ◽

...

Keyword(s):

Literature Review ◽

Industry 4.0 ◽

Design Methodology ◽

New Technologies ◽

Production Systems ◽

Qualitative Approach ◽

Sources Of Resistance ◽

Content Type ◽

Disturbance Management ◽

Different Sources

PurposeResistance is expected to emerge with the implementation and use of new technologies in production systems. This work focuses on identifying sources of resistance to the use of Industry 4.0 technologies when managing production disturbances and suitable managerial approaches to deal with them.Design/methodology/approachA qualitative approach was chosen in this research. The authors conducted a literature review and a series of interviews. Thirty-one papers from the literature review were analysed, and 16 people from five different companies were interviewed.FindingsThe authors identified five different sources of resistance and three managerial approaches to dealing with them. The sources of resistance were based on (1) feelings of over-supervision, (2) unclear values, (3) feelings of inadequacy, (4) concerns about loss of power and jobs and (5) work overload. The three approaches to dealing with resistance are (1) communication, (2) participation and (3) training.Originality/valueThis work identifies the sources and strategies to deal with resistance to the use of Industry 4.0 technologies in the management of production disturbances. The managerial literature in this area is limited, and to the authors's knowledge, the specific sources for resistance and strategies to deal with that in this topic have not been systematically investigated before.

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ASSOCIATION AMONG SOURCES OF RESISTANCE TO WITCHES' BROOM DISEASE FOR THE INCREMENT OF THE LEVEL AND DURABILITY OF THE CHARACTER

Agrotrópica (Itabuna) ◽

10.21757/0103-3816.2012v24n1p27-30 ◽

2012 ◽

Vol 24 (1) ◽

pp. 27-30 ◽

Cited By ~ 8

Author(s):

José Luis Pires ◽

Gilson Pires de Melo ◽

Milton Macoto Yamada ◽

Karina Peres Gramacho

Keyword(s):

Sources Of Resistance ◽

Broom Disease

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Histopathology of the Plasmodiophora brassicae-Chinese Cabbage Interaction in Hosts Carrying Different Sources of Resistance

Frontiers in Plant Science ◽

10.3389/fpls.2021.783550 ◽

2022 ◽

Vol 12 ◽

Author(s):

Xitong Liu ◽

Stephen E. Strelkov ◽

Rifei Sun ◽

Sheau-Fang Hwang ◽

Rudolph Fredua-Agyeman ◽

...

Keyword(s):

Chinese Cabbage ◽

Vascular System ◽

Plasmodiophora Brassicae ◽

Secondary Infection ◽

Root Hairs ◽

Recessive Gene ◽

Post Inoculation ◽

Sources Of Resistance ◽

Cortical Infection ◽

Different Sources

Clubroot is a serious soil-borne disease of crucifers caused by the obligate parasite Plasmodiophora brassicae. The genetic basis and histopathology of clubroot resistance in two Chinese cabbage (Brassica rapa ssp. pekinensis) inbred lines Bap055 and Bap246, challenged with pathotype 4 of P. brassicae, was evaluated. The Chinese cabbage cultivar “Juxin” served as a susceptible check. The resistance in Bap055 was found to be controlled by the CRa gene, while resistance in Bap246 fit a model of control by unknown recessive gene. Infection of the roots by P. brassicae was examined by inverted microscopy. Despite their resistance, primary and secondary infection were observed to occur in Bap055 and Bap246. Primary infection was detected at 2 days post-inoculation (DPI) in “Juxin,” at 4 DPI in Bap055, and at 6 DPI in Bap246. Infection occurred most quickly on “Juxin,” with 60% of the root hairs infected at 10 DPI, followed by Bap055 (31% of the root hairs infected at 12 DPI) and Bap246 (20% of the root hairs infected at 14 DPI). Secondary infection of “Juxin” was first observed at 8 DPI, while in Bap055 and Bap246, secondary infection was first observed at 10 DPI. At 14 DPI, the percentage of cortical infection in “Juxin,” Bap055 and Bap246 was 93.3, 20.0, and 11.1%, respectively. Although cortical infection was more widespread in Bap055 than in Bap246, secondary infection in both of these hosts was restricted relative to the susceptible check, and the vascular system remained intact. A large number of binucleate secondary plasmodia were observed in “Juxin” and the vascular system was disrupted at 16 DPI; in Bap055 and Bap246, only a few secondary plasmodia were visible, with no binucleate secondary plasmodia. The defense mechanisms and expression of resistance appears to differ between Chinese cabbage cultivars carrying different sources of resistance.

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Evaluation of different sources of resistance for breeding powdery mildew resistant grapevine varieties

International Journal of Horticultural Science ◽

10.31421/ijhs/5/1-2/19 ◽

1999 ◽

Vol 5 (1-2) ◽

Author(s):

J. Korbuly

Keyword(s):

Powdery Mildew ◽

Vitis Vinifera ◽

Wild Species ◽

Powdery Mildew Resistance ◽

East Asian ◽

Close Correlation ◽

Sources Of Resistance ◽

Mildew Resistance ◽

Additive Gene ◽

Different Sources

The appearance of resistance to powdery mildew was investigated on seedling progenies of interspecific crossings. Hybrids of American and East-Asian wild species and one Vitis vinifera variety (Janjal kara) were used as source of resistance in the crossings. The resistance of foliage and of berries were tested in the field at the time of vintage. The degree of resistance was ranked into six classes. In American and Asian hybrid derivatives there were few highly resistant progenies, but in the hybrids of Janjal kara variety more than 90 % of the progenies proved to be highly resistant to powdery mildew. According to the distribution of classes of resistance in the populations the resistance of American and Asian sources are mostly influenced by additive gene affects. The resistance of Janjal kara seemed to be mono or digenic. No close correlation was found between the powdery mildew resistance of the foliage and that of the berries.

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Development and Utilization of a Core Collection in Theobroma cacao based on RAPD Marker-based Estimates of Genetic Distance

HortScience ◽

10.21273/hortsci.32.3.513c ◽

1997 ◽

Vol 32 (3) ◽

pp. 513C-513

Author(s):

Jane M. Marita ◽

José Luis Pires ◽

W. Martin Aitken ◽

James Nienhuis

Keyword(s):

Genetic Diversity ◽

Genetic Distance ◽

Random Sampling ◽

Theobroma Cacao ◽

Core Collection ◽

Genetic Relationships ◽

Rapd Marker ◽

Sources Of Resistance ◽

Resistant Varieties ◽

Broom Disease

An increased need to understand the genetic relationships among cacao (Theobroma cacao) germplasm exists to identify cultivars that possess resistance to witches' broom disease (caused by Crinipellis perniciosa). Loss of production due to witches' broom disease in important cacao-growing areas, such as Bahia, Brazil, has generated a strong demand for disease-resistant varieties. Varieties based on single sources of resistance have been released; however, other genotypes are needed to enlarge the genetic diversity of cultivars in breeding programs. A core collection has been created to represent the range of genetic diversity available among the more than 600 cacao accessions at Centro de Pesquisa do Cacau (CEPEC). The cacao core facilitates access to the collection and is intended to enhance its use. This core collection was created from RAPD marker-based estimates of genetic distance among a subset of 270 accessions from the entire collection. The subset was sampled based on 1) witches' broom disease resistance data, 2) random sampling of the collection, and 3) random sampling of recently acquired accessions. Differences in RAPD marker frequencies were used to identify accessions in a witches' broom disease breeding program that contribute to the genetic diversity of the collection as a whole. In addition, differences in RAPD marker frequency allowed the comparison between accessions in the original collection and those acquired from new geographic regions that may expand the collection's genetic diversity.

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Mono-Locus and Pyramided Resistant Grapevine Cultivars Reveal Early Putative Biomarkers Upon Artificial Inoculation With Plasmopara viticola

Frontiers in Plant Science ◽

10.3389/fpls.2021.693887 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ramona Mihaela Ciubotaru ◽

Pietro Franceschi ◽

Luca Zulini ◽

Marco Stefanini ◽

Domen Škrab ◽

...

Keyword(s):

Plasmopara Viticola ◽

Pinot Noir ◽

Artificial Inoculation ◽

Sources Of Resistance ◽

Volatile Organic ◽

Primary Compounds ◽

Plant Metabolite ◽

Different Sources ◽

Resistant Genotypes ◽

Selection Of

One of the most economically important grapevine diseases is Downy mildew (DM) caused by the oomycete Plasmopara viticola. A strategy to reduce the use of fungicides to compensate for the high susceptibility of V. vinifera is the selection of grapevine varieties showing pathogen-specific resistance. We applied a metabolomics approach to evaluate the metabolic modulation in mono-locus resistant genotypes carrying one locus associated with P. viticola resistance (Rpv) (BC4- Rpv1, Bianca- Rpv3-1, F12P160- Rpv12, Solaris- Rpv10), as well as in pyramided resistant genotypes carrying more than one Rpv (F12P60- Rpv3-1; Rpv12 and F12P127- Rpv3-1, Rpv3-3; Rpv10) taking as a reference the susceptible genotype Pinot Noir. In order to understand if different sources of resistance are associated with different degrees of resistance and, implicitly, with different responses to the pathogen, we considered the most important classes of plant metabolite primary compounds, lipids, phenols and volatile organic compounds at 0, 12, 48, and 96 h post-artificial inoculation (hpi). We identified 264 modulated compounds; among these, 22 metabolites were found accumulated in significant quantities in the resistant cultivars compared to Pinot Noir. In mono-locus genotypes, the highest modulation of the metabolites was noticed at 48 and 96 hpi, except for Solaris, that showed a behavior similar to the pyramided genotypes in which the changes started to occur as early as 12 hpi. Bianca, Solaris and F12P60 showed the highest number of interesting compounds accumulated after the artificial infection and with a putative effect against the pathogen. In contrast, Pinot Noir showed a less effective defense response in containing DM growth.

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