Susceptibility of Hop Cultivars to Downy Mildew: Associations with Chemical Characteristics and Region of Origin

2016 ◽  
Vol 17 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Joanna L. Woods ◽  
David H. Gent
Keyword(s):  
United States ◽  
Downy Mildew ◽  
The United States ◽  
High Yield ◽  
Downy Mildew Resistance ◽  
Region Of Origin ◽  
Mildew Resistance ◽  
The United Kingdom ◽  
Pseudoperonospora Humuli ◽  
High Level

Hop downy mildew (caused by Pseudoperonospora humuli) is a yield-limiting disease in many hop-production regions of the world. In this research, 110 cultivars that are or were widely grown in the United States, Europe, or Australasia were evaluated in western Oregon over three years for their reaction to the shoot infection phase of downy mildew and vigor. There was a large range of downy mildew susceptibility and vigor amongst commercial cultivars, with some cultivars possessing a very high level of resistance. Overall, however, disease resistance and vigor were significantly greater in cultivars originating from Europe than those originating from the United States, Japan, and Australia/New Zealand. Amongst a subset of 79 cultivars, vigor was negatively correlated with levels, in cones, of cohumulone, a chemical constitute of bittering acids typically found in germplasm derived from North America. The generally poor vigor observed in cultivars derived outside of Europe likely is indicative of a lack of tolerance to the crown infection phase of the disease. Thus, the best sources of downy mildew resistance seems to be found in cultivars from the United Kingdom and continental Europe, and such cultivars are typically lower yielding and lack distinctive aroma and flavor characteristics presently desired by craft brewers. Introgression of downy mildew resistance into North American germplasm with high yield and desirable brewing characteristics is needed. Accepted for publication 3 March 2016. Published 7 March 2016.

scholarly journals Inheritance of True Leaf Stage Downy Mildew Resistance in Broccoli

2001 ◽  
Vol 126 (6) ◽  
pp. 727-729 ◽  
Author(s):  
Min Wang ◽  
Mark W. Farnham ◽  
Claude E. Thomas
Keyword(s):  
Downy Mildew ◽  
Control Method ◽  
Recurrent Parent ◽  
Downy Mildew Resistance ◽  
Resistant Parent ◽  
Dh Population ◽  
Mildew Resistance ◽  
Leaf Stage ◽  
True Leaf ◽  
High Level

Downy mildew, incited by the biotrophic fungal parasite, Peronospora parasitica (Pers. Fr.) Fr., is one of the most destructive diseases of broccoli (Brassica oleracea L., Italica Group) and other related crop species throughout the world. Cultivation of resistant cultivars is the most desirable control method because it provides a practical, long-term, and environmentally benign means of limiting damage from this disease. The commercial hybrid cultivar, Everest, has been shown previously to contain a high level of downy mildew resistance. Doubled-haploid (DH) lines developed from that hybrid were also shown to exhibit a similar, high level of resistance at the three- to four-leaf stage. To determine the mode of inheritance of this true leaf resistance, the resistant DH line was crossed to a susceptible line (derived from `Marathon') to produce an F1 hybrid. Subsequently, F2 and backcross (BC) populations were developed from the hybrid. In addition, a DH population of ≈100 lines was developed from the same F1 used to create the F2 and BC. All populations were evaluated for response to artificial inoculation with P. parasitica at the three- to four-leaf stage. F1 plants were resistant like the resistant parent and F2 populations segregated approximately nine resistant to seven susceptible. Using the resistant parent as recurrent parent, BC populations contained all resistant plants, while the BC to the susceptible parent fit a 1 resistant: 3 susceptible segregation ratio. These results can be explained by a model with two complementary dominant genes. This model was confirmed by the DH population that segregated ≈1:3, resistant to susceptible. Due to the dominant nature of this resistance, controlling genes should be easily incorporated into F1 hybrids and used commercially to prevent downy mildew.

scholarly journals HERITABILITY AND HETEROSIS OF GRAIN YIELD ON DOWNY MILDEW RESISTANCE (DMR) AND QUALITY PROTEIN MAIZE (QPM) INBREDS AND THEIR SINGLE CROSS HYBRIDS

Zuriat ◽  
2015 ◽  
Vol 16 (1) ◽  
Author(s):  
D. Ruswandi ◽  
N. Wicaksana ◽  
M. Rachmadi ◽  
A. Ismail ◽  
D. Arief ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Grain Yield ◽  
Downy Mildew ◽  
High Yield ◽  
Quality Protein Maize ◽  
Downy Mildew Resistance ◽  
Narrow Sense Heritability ◽  
Mildew Resistance ◽  
Single Cross ◽  
Single Cross Hybrids

Improvement of high yield maize cultivars possessing high quality of seed as showed by high lysine and tryptophan content must be fulfilled with resistance against downy mildew pathogen in any maize breeding program. A set of experiment to study genetic variability and to estimate both heritability and heterosis of important characters of grain yield on DMR and QPM lines has been conducted. Four downy mildew resistance (DMR) lines, i.e. Nei 9008, P 345, Ki 3, and MR 10; three quality protein maize (QPM) lines, including CML 161, CML 163, and CML 172; and their single cross hybrids formed based on line × tester mating design were used in the experiment. The following characters: height of the first ear, seeds number per row, seed weight per ear, and grain yield per plot showed broad genetic variability. Narrow sense heritability (hns) of grain yield and its components ranged from 0.01 to 0.71. Broad sense heritability (hbs), on the other hand, ranged from 0.20 to 0.74. It was found that hybrid derived from crossing between parental inbred lines possessing broad genetic background would express high heterosis.

scholarly journals Redistribution and Insurance in Welfare States Around the World

2020 ◽  
Author(s):  
Charlotte Bartels ◽  
Dirk Neumann
Keyword(s):  
United States ◽  
United Kingdom ◽  
The Elderly ◽  
The United States ◽  
Welfare States ◽  
Income Smoothing ◽  
Working Paper ◽  
The United Kingdom ◽  
Long Run ◽  
High Level

Redistribution across individuals in a one-year-period framework is an empirically intensely studied question. However, a substantial share of annual redistribution might turn out to serve individual insurance in a longer perspective, reducing the level of actual redistribution across individuals. This paper investigates to what extent long-run redistribution diverges from annual redistribution in welfare states of different types. Exploiting panel data from the Cross-National Equivalent File (CNEF) for Australia, Germany, South Korea, Switzerland, the United Kingdom, and the United States, we find that welfare states like Germany that are assumed to engage in a high level of redistribution actually achieve relatively less redistribution between individuals in the long run than the United Kingdom or the United States. Regression results show that a higher share of elderly in a country is associated with more annual redistribution, but with less long-run redistribution between individuals. The results suggest that, in welfare states with aging populations, we might expect growing annual redistribution that, to a substantial extent, is in fact income smoothing for the elderly. (Stone Center on Socio-Economic Inequality Working Paper Series)

scholarly journals Resistance of Cucumber Cultivars to a New Strain of Cucurbit Downy Mildew

HortScience ◽  
2012 ◽  
Vol 47 (2) ◽  
pp. 171-178 ◽  
Author(s):  
Adam D. Call ◽  
Adam D. Criswell ◽  
Todd C. Wehner ◽  
Kaori Ando ◽  
Rebecca Grumet
Keyword(s):  
North Carolina ◽  
Downy Mildew ◽  
The United States ◽  
Leaf Damage ◽  
High Yield ◽  
Breeding Lines ◽  
Yield And Quality ◽  
Resistant Lines ◽  
High Level ◽  
Moderately Resistant

Downy mildew, a foliar disease caused by the oomycete Pseudoperonospora cubensis (Berk. and Curt.) Rostow, is one of the most destructive pathogens of cucurbits. From 1961 to 2003, resistant cucumber cultivars in the United States had sufficient resistance to grow a successful crop without the use of fungicides. The pathogen resurged as a major problem in 2004. Since then, the dm-1 gene has not been effective against the new strain of downy mildew, and yield losses are high without the use of fungicides. The objective of this experiment was to identify cultivars having high yield and resistance to the new downy mildew. The experiment had 86 cultivars and breeding lines (hereafter collectively referred to as cultigens) and was conducted in Clinton, NC, in 2007 and 2009, in Castle Hayne, NC, in 2008 and 2009, and in Bath, MI, in 2007 to 2009. Plots were rated weekly on a 0 to 9 scale (0 = none, 1–2 = trace, 3–4 = slight, 5–6 = moderate, 7–8 = severe, and 9 = dead). Mean ratings for downy mildew leaf damage ranged from 2.9 to 5.7 in Michigan in 2008 and 2009 and from 3.8 to 6.8 in North Carolina in 2007 to 2009. None of the cultigens tested in this study showed a high level of resistance, although differences in resistance were detected. Lines WI 2757 and M 21 and cultivar Picklet were consistently among the top resistant lines in North Carolina and Michigan. The cultivars Coolgreen, Wis. SMR 18, and Straight 8 were identified as moderately to highly susceptible. An unreleased hybrid, ‘Nun 5053 F1’, and the cultivar Cates were the top yielding lines overall. The highest yield in a single year and location was from the cultivar Cates in Clinton, NC, in 2009, with 25.6 Mg·ha−1. The best cultivars in this study were only moderately resistant and would likely require fungicide applications to achieve high yield and quality in the presence of downy mildew. Until high resistance becomes available, growers would benefit by using fungicides in combination with tolerant and moderately resistant cultigens.

Effectiveness of Programs for the Prevention of Child Sexual Abuse

2020 ◽  
Vol 25 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Amaia Del Campo ◽  
Marisalva Fávero
Keyword(s):  
United States ◽  
Sexual Abuse ◽  
New Zealand ◽  
Critical Analysis ◽  
Prevention Programs ◽  
The United States ◽  
Sexual Abuse Prevention ◽  
Negative Effects ◽  
The United Kingdom ◽  
Methodological Considerations

Abstract. During the last decades, several studies have been conducted on the effectiveness of sexual abuse prevention programs implemented in different countries. In this article, we present a review of 70 studies (1981–2017) evaluating prevention programs, conducted mostly in the United States and Canada, although with a considerable presence also in other countries, such as New Zealand and the United Kingdom. The results of these studies, in general, are very promising and encourage us to continue this type of intervention, almost unanimously confirming its effectiveness. Prevention programs encourage children and adolescents to report the abuse experienced and they may help to reduce the trauma of sexual abuse if there are victims among the participants. We also found that some evaluations have not considered the possible negative effects of this type of programs in the event that they are applied inappropriately. Finally, we present some methodological considerations as critical analysis to this type of evaluations.

Science, Politics, and the Pandemic

2020 ◽  
Vol 119 (820) ◽  
pp. 303-309
Author(s):  
J. Nicholas Ziegler
Keyword(s):  
United States ◽  
Biomedical Research ◽  
Scale Up ◽  
Political Leadership ◽  
The United States ◽  
Scientific Advice ◽  
The United Kingdom ◽  
Effective Policy ◽  
Scientific Expertise ◽  
The Uk

Comparing the virus responses in Germany, the United Kingdom, and the United States shows that in order for scientific expertise to result in effective policy, rational political leadership is required. Each of these three countries is known for advanced biomedical research, yet their experiences in the COVID-19 pandemic diverged widely. Germany’s political leadership carefully followed scientific advice and organized public–private partnerships to scale up testing, resulting in relatively low infection levels. The UK and US political responses were far more erratic and less informed by scientific advice—and proved much less effective.

Sign in / Sign up

Export Citation Format

Share Document