Race Differentials Research Articles

イネいもち病菌レースの分化およびいもち病の環境保全型防除に関する研究

イネいもち病菌レースの分化およびいもち病の環境保全型防除に関する研究

Does the Gender of the Intake Probation Officer Contextualize the Treatment of Black Youth?

The presence of race differentials in case outcomes has recently been explained by a focus on the characteristics of the decision makers within the context of the interplay between discretion, a reliance on stereotyping, and the perceptions of decision makers. We continue this line of inquiry by assessing what effects the gender of the intake officer may have in understanding the treatment of male youth. Using data from juvenile court records within a single juvenile court jurisdiction, the research is guided by two general questions. Do female and male officers make similar intake decisions once relevant legal and extralegal considerations related to the youth are controlled? Do female and male officers rely on similar legal and extralegal considerations and give equal weight to those considerations when making intake decisions? The results from our inquiry have implications for broadening the scope of the contexts of intake juvenile justice decision making, especially in terms of how the characteristics of decision makers influence case outcomes. The implications of the results may also better inform efforts that address the equitable treatment of youth in the juvenile justice system.

Genetic differentiation among sympatric cuckoo host races: males matter

Generalist parasites regularly evolve host-specific races that each specialize on one particular host species. Many host-specific races originate from geographically structured populations where local adaptations to different host species drive the differentiation of distinct races. However, in sympatric populations where several host races coexist, gene flow could potentially disrupt such host-specific adaptations. Here, we analyse genetic differentiation among three sympatrically breeding host races of the brood-parasitic common cuckoo, Cuculus canorus. In this species, host-specific adaptations are assumed to be controlled by females only, possibly via the female-specific W-chromosome, thereby avoiding that gene flow via males disrupts local adaptations. Although males were more likely to have offspring in two different host species (43% versus 7%), they did not have significantly more descendants being raised outside their putative foster species than females (9% versus 2%). We found significant genetic differentiation for both biparentally inherited microsatellite DNA markers and maternally inherited mitochondrial DNA markers. To our knowledge, this is the first study that finds significant genetic differentiation in biparentally inherited markers among cuckoo host-specific races. Our results imply that males also may contribute to the evolution and maintenance of the different races, and hence that the genes responsible for egg phenotype may be found on autosomal chromosomes rather than the female-specific W-chromosome as previously assumed.

Molecular Variation Among Isolates of Verticillium dahliae and Polymerase Chain Reaction-Based Differentiation of Races

Verticillium dahliae is a soilborne fungal pathogen that causes vascular wilt in a variety of economically important crops worldwide. There are two races of V. dahliae that infect tomato and lettuce. Although race-1-specific resistance has been identified in both tomato and lettuce, no resistant sources are available for race 2. Molecular analyses were employed to characterize the genetic variability and race structure of 101 isolates of V. dahliae from a variety of hosts, mainly from central and coastal California, and 10 isolates exotic to this area. Analyses of the 16 simple sequence repeat (SSR) markers illustrated that tomato subpopulations from central California were distinct relative to the marigold subpopulations. In contrast, cotton and olive isolates showed admixture with tomato isolates. Analyses of both the ribosomal DNA intergenic spacer regions and SSR markers revealed high genetic variability among isolates but were unable to delineate races of V. dahliae. However, a polymerase chain reaction (PCR) assay was applied to amplify a race-1-specific amplicon from the isolates in many hosts from different geographic areas, and was coupled with virulence assays for validation of the data. Results of the PCR assay showed 100% concordance with the virulence assay to differentiate race 1 from race 2 of 48 isolates from tomato. The results indicate that the PCR assay can be applied to differentiate the two races to support our related aim of breeding host resistance, and further reveal insights into the distribution of races in tomato and lettuce cropping systems in California.

A Sequence-amplified Characterized Region Marker for a Single, Dominant Gene in Melon PI 134198 that Confers Resistance to a Unique Race of Podosphaera xanthii in China

Melon production in China is threatened by cucurbit powdery mildew incited by Podosphaera xanthii, which can cause severe yield losses. Disease reactions of 10 melon P. xanthii race differentials indicated the presence of a unique race of P. xanthii, denoted pxCh1, in the Shanghai area. Resistance to P. xanthii race pxCh1 in melon PI 134198, which originated from India, was controlled by a single, dominant gene, designated Pm-8, in a cross with susceptible melon inbred S717. A search for a molecular marker linked to Pm-8 was initiated using the same cross. Bulk segregant analysis of their F2 progeny revealed one sequence-related amplified polymorphism (SRAP) marker of 148 bp linked to Pm-8, at 3.9 cM. The SRAP segment was recovered, cloned, and sequenced and converted into a sequence-amplified characterized region marker for marker-assisted selection of Pm-8 in breeding programs to develop melon cultivars resistant to P. xanthii race pxCh1.

국내 고추 역병균의 병원성 분화

본 연구는 고추 역병균의 교배형 분포와 병원성 분화를 구명하기 위하여 수행하였다. 2005년부터 2007년까지 고추 역병에 감염된 식물로부터 총 143균주를 분리하였고 분리된 균주의 교배형을 조사하였다. 2005년 분리된 20균주 중 A1 교배형이 75%, A2 교배형이 25%인 것으로 조사되었다. 2006년 분리된 총 91균주 중 A1 교배형이 49.0%이고 A2 교배형이 42.9%로 나타났으며 교배가 되지 않는 S형(sterile type)이 3.3%로 분리되었다. 2007년 분리된 균주는 2006년과 비슷한 양상을 나타내었다. 전체 143균주의 교배형은 A1 56.6%, A2 39.2%, S형 4.2%로 조사되었다. 50종 고추에 교배형이 다른 대표적인 3균주를 접종하여 병원성 반응이 다른 13개의 고추를 선발하여 고추 역병균 병원성 분화 조사를 위한 판별품종군을 만들었다. 고추역병 판별품종군을 이용하여 병원성 여부를 조사한 결과 11종의 서로 다른 병원성 반응을 나타내는 것으로 조사되었다. 이를 통해 국내에 최소 11개의 고추 역병균 레이스가 존재한다는 것을 확인할 수 있었다. This study was examined to identify the race differentiation and distribution of mating type on Phytophthora capsici population in Korea. One hundred forty three isolates of P. capsici were collected from several locations of Korea in 2005-2007. In 2005, 20 isolates of P. capsici were collected and surveyed as A1 mating type of 75% and A2 mating type of 25%. In 2006, a total of 91 isolates were collected and separated as A1 mating type of 49.0%, A2 mating type of 42.9% and S type (sterile) of 3.3%. Isolates obtained in 2007 were similar to 2006 results. Totally, ratio of mating type of 153 isolates was confirmed that A1 type was 56.6%, A2 type was 39.2%, and S type was 4.2%. Thirteen pepper cultivars with different pathogenic response to 3 typical isolates having different mating were screened among 50 pepper cultivars and determined as race differential cultivars for investigation. The 11 races of P. capsici were found by using 13-race differential cultivars. These results indicated that at least 11 races of P. capsici are existed and confirmed race differentiation of P. capsici in pepper.

Cucurbit downy mildew (Pseudoperonospora cubensis)—biology, ecology, epidemiology, host-pathogen interaction and control

Cucurbit downy mildew, caused by the oomycete Pseudoperonospora cubensis, is a devastating, worldwide-distributed disease of cucurbit crops in the open field and under cover. This review provides recent data on the taxonomy, biology, ecology, host range, geographic distribution and epidemiology of P. cubensis. Special attention is given to host-pathogen interactions between P. cubensis and its economically-important cucurbit hosts (Cucumis sativus, C. melo, Cucurbita pepo, C. maxima, and Citrullus lanatus); pathogenic variability in P. cubensis at the species, genus, and population levels; and, differentiation of pathotypes and races. Genetics and variability of host resistance and cellular and molecular aspects of such resistance are considered. A focus is given to methods of crop protection, including prevention and agrotechnical aspects, breeding for resistance—classical and transgenic approaches, chemical control and fungicide resistance. Novel technologies in biological and integrated control are also discussed. This review also summarizes the most important topics for future research and international collaboration.

MALE MARITAL WAGE DIFFERENTIALS: TRAINING, PERSONAL CHARACTERISTICS, AND FIXED EFFECTS

Using the National Longitudinal Survey of Youth 1979, we replicate previous estimates of the marital wage differential for white men, extend the analysis to African American men, then explain the within and between race differentials. We first control for formal job training, then for cognitive skills, parental background, and self‐esteem with little effect. By contrast, the white differential but not the black differential disappears in fixed‐effects estimation. We reconcile the cross‐section/panel differentials by focusing on the distinct identification conditions employed by each technique. Men who never change marital status play a significant role in white cross‐sectional estimates. (JEL J31, J12)

Prevalence and timing of diagnosable mental health, alcohol, and substance use problems among older adolescents in the child welfare system

This study reports the prevalence of PTSD, major depression, alcohol abuse/dependence and substance abuse/dependence diagnoses assessed with a structured clinical interview protocol in a population-based, multi-state, age cohort of older adolescents about to exit child welfare systems. PTSD was the most common diagnosis and was observed at rates above those seen in the general population. Rates of specific diagnoses varied according to gender, race, type of child welfare placement, and state of residence. In general, African American youth and those in kinship family foster care were less likely to have mental health and substance use problems. Analysis of the timing of onset relative to entry into care revealed that Caucasian youth were more likely to have diagnoses prior to entry into state custody, and race differentials were less pronounced for diagnosis after placement in foster care. Observed state-to-state differences suggest that age of entry into care and the likelihood of pre-existing mental health and substance use conditions could be attributable to child welfare policies regarding screening and placement.

Morphological and pathogenic variability of Indian isolates of Fusarium oxysporum f. sp. ciceris causing chickpea wilt

Wilt of chickpea (Cicer arietinum) caused by Fusarium oxysporum f. sp. ciceris is prevalent in almost all chickpea growing areas of the world and its incidence varied from 14.1 to 32.0% in the different states of India surveyed. The isolates were highly variable in their colony growth pattern, size of colony and pigmentations. The size of microconidia varied from 5.1–12.8 × 2.5–5.0 μm, whereas macroconidia ranged from 16.5–37.9 × 4.0–5.9 μm with 1–5 septations. One hundred and twelve isolates were grouped into 12 categories on the basis of their radial growth, size of macroconidia and growth pattern. Majority of the isolates were highly pathogenic causing more than 50% wilt in chickpea cultivar JG 62. Virulence analysis of 56 representative isolates on a set of 18 cultivars of chickpea, including 10 international differentials, grouped them into three categories. Chickpea cultivar KWR 108 differentiated all isolates of Punjab, Haryana and Delhi states and a few isolates of Rajasthan from others by showing resistant reactions and were placed in the first group. The rest of the isolates of Rajasthan state showed susceptible reactions on KWR 108 placed in a second group. Cultivar CPS 1 distinguished the isolates of Jharkhand state and placed them into a third group. An international set of cultivars recommended for race differentiation were not able to distinguish all the isolates into known races of the pathogen, therefore cultivar KWR 108 should be included in the existing differential set of cultivars.

Phylogeography and host race differentiation in the European mistletoe (Viscum album L.)

Mistletoes are bird dispersed, hemi-parasitic shrubs infecting a large number of woody host plants. Chloroplast fragment length polymorphisms were used to study genetic differentiation among presumed host races, population genetic structure, and to elucidate the postglacial migration history of mistletoe (Viscum album) across the entire natural distribution range in Europe. The populations sampled belong to four closely related taxa, three of which are widely distributed and differ in their host trees, whereas a fourth taxon is rare and endemic to the Island of Crete. The molecular analysis of chloroplast DNA variation supported the distinction of these four taxa. We further found evidence for phylogeographical structure in each of the three widely distributed host races. Independent of host race, mistletoe haplotypes from Turkey were distinct and distant from those found elsewhere in Europe, suggesting that highly differentiated populations, and possibly new taxa, exist at the range limit of the species.

Race differentials in employment effects of psychological distress: A study of non-Hispanic Whites and African-Americans in the United States

This study used two sub-samples of African-Americans and non-Hispanic Whites from the 2002–2003 U.S. National Survey on Drug Use and Health to examine differential effects of psychological distress (PD) on employment. Failing to reject exogeneity of PD in the employment specifications, we estimated standard probit of employment. We found that PD significantly reduced employment probability regardless of race; but the reduction was 7.4% for African-Americans, compared to 5.3% for Whites. Using individuals with PD only, we estimated the Oaxaca–Blinder decomposition and found endowments explained 61% of employment differences between Whites with PDs and African-Americans with PDs while 39% of these differences were due to unexplained factors. These findings suggest that targeted policies for prevention and effective treatment of PD might yield higher employment benefits for minorities.

Genetic differentiation in sympatric populations of the groundnut seed beetle Caryedon serratus (Coleoptera: Chrysomelidae): new insights from molecular and ecological data

Abstract. The extent of genetic differentiation between native and groundnut-feedingforms of the groundnut seed beetle Caryedon serratus Olivier was studied. Sixteen samples(560 individuals of both sexes collected in four localities in Senegal) of C. serratus werereared from pods of four distinct host plants (Arachis hypogaea L., Bauhinia rufescens Lam.,Piliostigma reticulatum (DC) Hochst and Tamarindus indica L.), and five microsatellite lociwere analysed. Phylogenetic and statistical analyses indicated that host plants stronglyinfluence the degree of genetic differentiation between sampled individuals. Within hostplants, genetic differentiation was low. Genetic differentiation between hosts was highlysignificant (average u¼ 0.374) and geographical distances between localities did notinfluence the genetic structuration of C. serratus populations from a given host plant. Theresults of this study show that C. serratus could be under a host race formation process.Key words: Caryedon serratus, microsatellites, genetic differentiation, groundnut, hostplants, SenegalIntroductionHost race differentiation within populations, orgenetic differentiation in host use, is a widespreadphenomenon among insects and other invertebrates(Bush and Smith, 1998; Strauss and Zangler, 2002).Althoughthepossibilitythatitcanresultinsympatricspeciation is still debated, it may well be one of themajormechanismsthatledtopresent-daydiversityinherbivorous insects (Bernays and Chapman, 1994).One of the arguments against sympatric speciationvia host shift and host race formation is that theexistence of host races has not been demonstrated(Futuyma et al., 1993). However, establishing thebiological status of sympatric sister populationsutilizing different hosts is fairly straightforwardand objective. This does not necessarily imply thatthese host races have differentiated while insympatry, but such a demonstration is a necessarystep for investigating sympatric speciation viahost race formation. Recent studies (Bradshaw et al.,

Recombinant Inbred Line Differential Identifies Race-Specific Resistance to Phytophthora Root Rot in Capsicum annuum

A differential series is the normal method for identification of races within a plant pathogen and a host interaction. A host differential is extremely useful for phytopathological as well as breeding purposes. A set of recombinant inbred lines (RILs) were developed and characterized for race differentiation of Phytophthora root rot caused by Phytophthora capsici. The highly resistant Capsicum annuum accession Criollo de Morelos-334 was hybridized to a susceptible cultivar, Early Jalapeno, to generate the RIL population. The host differential characterized 17 isolates of P. capsici into 13 races. The establishment of a stable host differential for the P. capsici and C. annuum interaction will assist researchers in understanding the complex inheritance of resistance to Phytophthora root rot and to develop resistant cultivars.

Isolation and identification of Phytophthora capsici in Guangdong Province and measurement of their pathogenicity and physiological race differentiation

Five isolates collected from different pepper-cropping regions in Guangdong Province, China were determined. Based on their morphological characteristics and symptoms after being re-inoculated to pepper, these isolates were identified as Phytophythora capsici Leonian. The sporangia induced on carrot medium (CA) were morphologically similar and most of their shapes were ovate or elliptic, and obviously papillate. The mean size of the sporangium was 40.8–45.9 (l) μm × 23.2–30.9 (b) μm, with l/b ratio 1.4–1.8. There were evident differences in my celial growth rate, productivity of sporangia and pathogenicity to pepper among the isolates. A test of physiological characteristics showed that one isolate was determined as Race 1, and the other four isolates belonged to Race 3. It is concluded that Race 3 is most likely to be the predominent race in Guangdong Province, China.

Host‐race formation in Chaetostomella cylindrica (Diptera: Tephritidae): Morphological and morphometric evidence

Chaetostomella cylindrica is a highly oligophagous tephritid infesting the flower heads of six genera and 10 species of thistles in Lebanon, and is predominant on two hosts in sympatry, Notobasis syriaca and Onopordum illyricum. Adult flies emerging from N. syriaca fit more closely the description of the species with respect to the colour and pattern on the mesonotum. This study compares morphometrically and morphologically the host races associated with N. syriaca and O. illyricum. Immatures of both races were similar, but all stages of the Onopordum‐associated race were significantly larger. Morphometric studies, based on two head and five wing measurements, using canonical discriminant analysis, allowed for the differentiation of the host races with more than 70% accuracy. The aculeus shape and length differed significantly between females of both races. The holotype of Trypeta lurida Loew 1844 was examined and appeared closer to the Onopordum host race. Chaetostomella cylindrica appears to be a complex of cryptic and reproductively isolated species. Present address: Mohammad S. Al‐Zein, Old Dominion University, Norfolk, VA, USA.

Long and happy living: Trends and patterns of happy life expectancy in the U.S., 1970–2000

This study assesses the trends and differentials in length of quality life in the U.S. population as measured by happy life expectancy in 1970, 1980, 1990, and 2000. The analysis combines age-specific prevalence rates of subjective well-being from a large nationally representative survey and life table estimates of mortality in decennial Census years. Employing the period prevalence-rate life table method—Sullivan method, the analysis finds evidence for improvement in quality of life in the U.S. Happy life expectancy largely increased in both absolute terms (number of years) and relative terms (proportion of life) over time at all adult ages examined. And increases in total life expectancy were mainly contributed by increases in expectancy in happy years rather than unhappy years. Happy life expectancy is longer than active life expectancy. And there has been greater compression of unhappiness than compression of morbidity. There are substantial differentials in happy life expectancy by sex and race because of differential prevalence rates of happiness. Women and whites had longer years of total and happy life expectancies at most ages and dates, while men and blacks had greater proportions of happy life expectancies across the three decades. Although race differentials generally decreased at older ages and with time, relative disadvantages of blacks persisted.

A Rapid Technique for Determination of Races of Phytophthora nicotianae on Tobacco.

A laboratory technique for determining races of Phytophthora nicotianae on tobacco (Nicotiana tabacum) was developed and compared with a commonly used greenhouse method. The laboratory technique was based on production and inoculation of tobacco seedlings in tissue culture plates. Three P. nicotianae isolates from North Carolina previously determined as race 0 and 1 were used. Four tobacco cultivars and two breeding lines with different types of resistance were used as differential cultivars: K-326, K-346, NC-71, NC-1071, L8, and Ky14xL8. Plants were evaluated 7 and 14 days after inoculation. Five differential cultivars (K-326, K-346, NC-1071, NC-71, and L8) were determined to be sufficient to differentiate races 0 and 1. Cv. Ky14xL8 was ineffective for differentiation of races and produced inconsistent results. The laboratory technique was as effective as the greenhouse technique for distinguishing different races of P. nicotianae for every isolate in all experiments. Additionally, the most reliable results for both methods were obtained when evaluations were made 14 days after inoculation. The laboratory technique was validated with 21 isolates collected from four counties in North Carolina. The laboratory technique produced results 2 weeks faster than the greenhouse technique and required significantly less space and labor than the greenhouse technique for the same number of isolates. Additionally, the larger number of seedlings used in the laboratory technique increased the robustness of the results, especially for isolates for which race identification was unclear with the greenhouse technique. We propose that the laboratory technique has the potential for evaluation of tobacco resistance in other pathosystems as well.

Phenotypic and genotypic identification of anthracnose resistance in kidney bean cultivars grown in western Canada

Five previously published molecular markers that are closely linked to the genes conditioning the resistance of common bean (Phaseolus vulgaris) to anthracnose (Colletotrichum lindemuthianum) and the seedling reactions to six anthracnose races were used to detect the presence or absence of four anthracnose resistance genes in seven kidney bean entries, five race differentials and two check cultivars. Under controlled environmental conditions, the kidney bean cultivar Napoleon and the navy bean Envoy were resistant against all of the anthracnose races and they appear to combine resistance genes Co-1 and Co-2 with either a third unidentified gene or is controlled by Co-12. The kidney bean cultivar AC Elk was only susceptible to race 31, which suggested that it carries genes Co-1 and Co-2, but molecular analyses only detected the presence of Co-1. Kidney bean cultivar GTS 401 was susceptible to all the races and no resistance genes were detected. Five other kidney bean entries, namely AC Calmont, Pink Panther, W K380, Red Hawk and Michigan Dark Red Kidney (MDRK), were only susceptible to races 2, 23 and 31. In these five kidney bean cultivars, the presence of gene Co-1 alone conferred the resistance to races 73, 89 and 1096. Genes Co-4, Co-42 and Co-5 were not detected with molecular markers in any of the seven kidney bean entries. Key words: Anthracnose (Colletotrichum lindemuthianum), disease resistance, gene identification, kidney bean (Phaseolus vulgaris)

Selective Sweeps Reveal Candidate Genes for Adaptation to Drought and Salt Tolerance in Common Sunflower, Helianthus annuus

Here we report the results of an analysis of variation at 128 EST-based microsatellites in wild Helianthus annuus, using populations from the species' typical plains habitat in Kansas and Colorado, as well as two arid desert and two distinct brackish marsh areas in Utah. The test statistics lnRV and lnRH were used to find regions of the genome that were significantly less variable in one population relative to the others and thus are likely to contain genes under selection. A small but detectable percentage (1.5-6%) of genes showed evidence for selection from both statistics in any particular environment, and a total of 17 loci showed evidence of selection in at least one environment. Distance-based measures provided additional evidence of selection for 15 of the 17 loci. Global F(ST)-values were significantly higher for candidate loci, as expected under divergent selection. However, pairwise F(ST)-values were lower for populations that shared a selective sweep. Moreover, while spatially separated populations undergoing similar selective pressures showed evidence of divergence at some loci, they evolved in concert at other loci. Thus, this study illustrates how selective sweeps might contribute both to the integration of conspecific populations and to the differentiation of races or species.