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1.
Science ; 384(6696): 697-703, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38723080

ABSTRACT

Changes in climate shift the geographic locations that are suitable for malaria transmission because of the thermal constraints on vector Anopheles mosquitos and Plasmodium spp. malaria parasites and the lack of availability of surface water for vector breeding. Previous Africa-wide assessments have tended to solely represent surface water using precipitation, ignoring many important hydrological processes. Here, we applied a validated and weighted ensemble of global hydrological and climate models to estimate present and future areas of hydroclimatic suitability for malaria transmission. With explicit surface water representation, we predict a net decrease in areas suitable for malaria transmission from 2025 onward, greater sensitivity to future greenhouse gas emissions, and different, more complex, malaria transmission patterns. Areas of malaria transmission that are projected to change are smaller than those estimated by precipitation-based estimates but are associated with greater changes in transmission season lengths.


Subject(s)
Anopheles , Climate Change , Hydrology , Malaria , Mosquito Vectors , Water , Animals , Humans , Africa/epidemiology , Anopheles/parasitology , Greenhouse Gases/analysis , Malaria/transmission , Mosquito Vectors/parasitology , Rain , Seasons , Water/parasitology , Plasmodium , Epidemiological Models
3.
BMC Nutr ; 8(1): 80, 2022 Aug 16.
Article in English | MEDLINE | ID: mdl-35974401

ABSTRACT

BACKGROUND: There are a range of policies and guidelines focused on meat consumption which aim to tackle health and environmental issues. Policies are often siloed in nature and propose universal limits on consumption. Despite this, there will be a number of conflicts and trade-offs between interest groups. This study explores secondary impacts associated with guidelines issued by the World Cancer Research Fund and assesses the utility of a targeted policy intervention strategy for reducing red meat consumption. METHODS: We used highly detailed consumption data of over 5,000 individuals from the National Diet and Nutrition Survey. We firstly compared individual consumption against the policy guidelines to identify demographic groups most likely to consume above recommended levels. We then synthetically modified the food diary data to investigate the secondary impacts of adherence to the recommendations by all individuals. We assessed changes in overall consumption, nutrient intake (iron, zinc, vitamin B12, vitamin B3, fat and saturated fat) and global warming potential. We also projected future impacts under various population projections. RESULTS: We found that certain demographic groups are much more likely to exceed the recommendations and would therefore benefit from a targeted intervention approach. Our results provide a baseline for which the impacts of any meat substitute diets can be assessed against. Whilst secondary health benefits may be realised by reducing intake of certain nutrients (e.g. fats), negative impacts may occur due to the reduced intake of other nutrients (e.g. iron, zinc). Reduced overall consumption is likely to have implications for the wider meat industry whilst complementary impacts would occur in terms of reduced greenhouse gas emissions. Impacts will be counteracted or maybe even reversed by any substitute products, highlighting the need to carefully consider the suitability and impacts of meat-replacements. CONCLUSION: The future structure of the meat industry will depend on how conflicts and trade-offs are addressed and how more holistic policy ideas are implemented. This research provides a framework for using demographic and consumption data to reduce negative trade-offs and improve policy effectiveness.

4.
Sci Rep ; 11(1): 24284, 2021 12 20.
Article in English | MEDLINE | ID: mdl-34931039

ABSTRACT

Himalayan glaciers are undergoing rapid mass loss but rates of contemporary change lack long-term (centennial-scale) context. Here, we reconstruct the extent and surfaces of 14,798 Himalayan glaciers during the Little Ice Age (LIA), 400 to 700 years ago. We show that they have lost at least 40 % of their LIA area and between 390 and 586 km3 of ice; 0.92 to 1.38 mm Sea Level Equivalent. The long-term rate of ice mass loss since the LIA has been between - 0.011 and - 0.020 m w.e./year, which is an order of magnitude lower than contemporary rates reported in the literature. Rates of mass loss depend on monsoon influence and orographic effects, with the fastest losses measured in East Nepal and in Bhutan north of the main divide. Locally, rates of loss were enhanced with the presence of surface debris cover (by 2 times vs clean-ice) and/or a proglacial lake (by 2.5 times vs land-terminating). The ten-fold acceleration in ice loss we have observed across the Himalaya far exceeds any centennial-scale rates of change that have been recorded elsewhere in the world.

5.
Appl Spat Anal Policy ; 14(3): 563-590, 2021.
Article in English | MEDLINE | ID: mdl-34721723

ABSTRACT

The future of the meat industry will require the management of important trade-offs between economic, environmental and health aspects of both humans and animals. Understanding the patterns and trends of meat expenditure and consumption is crucial for assessing the current resilience of the system and for economic, planning, health and environmental applications. Here, we show how the technique of geodemographic classification, combined with fine scale expenditure estimates can be used to explore temporal and spatial patterns of meat expenditure in Great Britain between 2008 and 2017. Whilst the expenditure patterns of some food categories such as sausages remained relatively consistent, others such as lamb show a trend towards a reduced proportion of expenditure and increased inequality of purchases. Short term changes in expenditure patterns also occurred, potentially due to product specific price variability, price elasticities or zoonotic disease scare. Environmental attitudes, financial constraints and the prominence of communities who do not eat meat for religious or cultural reasons are likely to be driving the differences between geodemographic groups. The methodology and results could be a valuable tool for policy makers in the meat industry and beyond.

6.
Lancet Glob Health ; 9(6): e802-e812, 2021 06.
Article in English | MEDLINE | ID: mdl-34019836

ABSTRACT

BACKGROUND: Understanding subnational variation in age-specific fertility rates (ASFRs) and total fertility rates (TFRs), and geographical clustering of high fertility and its determinants in low-income and middle-income countries, is increasingly needed for geographical targeting and prioritising of policy. We aimed to identify variation in fertility rates, to describe patterns of key selected fertility determinants in areas of high fertility. METHODS: We did a subnational analysis of ASFRs and TFRs from the most recent publicly available and nationally representative cross-sectional Demographic and Health Surveys and Multiple Indicator Cluster Surveys collected between 2010 and 2016 for 70 low-income, lower-middle-income, and upper-middle-income countries, across 932 administrative units. We assessed the degree of global spatial autocorrelation by using Moran's I statistic and did a spatial cluster analysis using the Getis-Ord Gi* local statistic to examine the geographical clustering of fertility and key selected fertility determinants. Descriptive analysis was used to investigate the distribution of ASFRs and of selected determinants in each cluster. FINDINGS: TFR varied from below replacement (2·1 children per women) in 36 of the 932 subnational regions (mainly located in India, Myanmar, Colombia, and Armenia), to rates of 8 and higher in 14 subnational regions, located in sub-Saharan Africa and Afghanistan. Areas with high-fertility clusters were mostly associated with areas of low prevalence of women with secondary or higher education, low use of contraception, and high unmet needs for family planning, although exceptions existed. INTERPRETATION: Substantial within-country variation in the distribution of fertility rates highlights the need for tailored programmes and strategies in high-fertility cluster areas to increase the use of contraception and access to secondary education, and to reduce unmet need for family planning. FUNDING: Wellcome Trust, the UK Foreign, Commonwealth and Development Office, and the Bill & Melinda Gates Foundation.


Subject(s)
Birth Rate/trends , Developed Countries/statistics & numerical data , Developing Countries/statistics & numerical data , Cross-Sectional Studies , Geography , Humans
7.
Sci Rep ; 10(1): 13392, 2020 08 07.
Article in English | MEDLINE | ID: mdl-32770050

ABSTRACT

Rapid changes observed today in mountain glaciers need to be put into a longer-term context to understand global sea-level contributions, regional climate-glacier systems and local landscape evolution. In this study we determined volume changes for 400 mountain glaciers across the Southern Alps, New Zealand for three time periods; pre-industrial "Little Ice Age (LIA)" to 1978, 1978 to 2009 and 2009 to 2019. At least 60 km3 ± 12 km3 or between 41 and 62% of the LIA total ice volume has been lost. The rate of mass loss has nearly doubled from - 0.4 m w.e year-1 during 1,600 to 1978 to - 0.7 m w.e year-1 at present. In comparison Patagonia has lost just 11% of it's LIA volume. Glacier ice in the Southern Alps has become restricted to higher elevations and to large debris-covered ablation tongues terminating in lakes. The accelerating rate of ice loss reflects regional-specific climate conditions and suggests that peak glacial meltwater production is imminent if not already passed, which has profound implications for water resources and riverine habitats.

8.
Sci Data ; 6(1): 56, 2019 May 13.
Article in English | MEDLINE | ID: mdl-31086192

ABSTRACT

We present expenditure estimates for 106 product categories across Great Britain for the years 2008-2016. Estimates are at the Local Authority District level (n = 380) and the categories cover all food, drink and tobacco commodities. Reliable, local level expenditure estimates are crucial for understanding broader market trends, assessing economic stability and for projections. This is especially important for commodities such as alcohol, tobacco and unhealthy foods due to their role in the prevalence of non-communicable diseases. There has been relatively little research into local area spatial patterns of expenditure, with existing estimates often of insufficient resolution for informing planning decisions. We use spatial microsimulation to create an archive of expenditure datasets. This was achieved by linking socio-demographic foundations with detailed datasets on individual expenditure. Whilst initially developed to aid investigations into sociodemographic trends in the meat industry, the data have reuse potential in a number of disciplines, including public health, economics, retail geography and environmental management. The framework could be applied to other regions with appropriate data.


Subject(s)
Beverages/economics , Food/economics , Tobacco Products/economics , Commerce , Computer Simulation , Family Characteristics , Humans , Income , Socioeconomic Factors , United Kingdom
9.
PLoS One ; 13(12): e0209753, 2018.
Article in English | MEDLINE | ID: mdl-30596721

ABSTRACT

BACKGROUND: Low-velocity motor vehicle crashes often lead to severe and chronic neck disorders also referred to as whiplash-associated disorders (WAD). The etiology of WAD is still not fully understood. Many studies using a real or simulated collision scenario have focused on rear-end collisions, whereas the kinematics and muscular responses during frontal-oblique collisions have hardly been investigated. In particular for rear-end collisions, drivers were shown to have a higher WAD risk than front seat passengers. Yet, independently from the impact direction, neither the muscular nor the kinematic responses of drivers and front seat passengers have been compared to date, although some findings indicate that the neck muscles have the potential to alter the head and neck kinematics, and that the level of neck muscle activity during impact may be relevant for the emergence of WAD. OBJECTIVE: In this study, we quantitatively examined the subjects' neck muscle activity during low-velocity left-frontal-oblique impacts to gain further insights into the neuromuscular mechanism underlying whiplash-like perturbations that may lead to WAD. METHODS: In a within-subject study design, we varied several impact parameters to investigate their effect on neck muscle response amplitude and delay. Fifty-two subjects experienced at least ten collisions while controlling for the following parameters: change in velocity Δv (3 / 6 km/h), seating position (driver / front seat passenger), and deliberate pre-tension of the musculature (tense / relaxed) to account for a potential difference between an expected and an unexpected crash. Ten of the 52 subjects additionally ran the same experimental conditions as above, but without wearing a safety belt. FINDINGS: There were significant main effects of Δv and muscle pre-tension on the reflex amplitude but not of seating position. As for the reflex delay, there was a significant main effect of muscle pre-tension, but neither of Δv nor of seating position. Moreover, neither the safety belt nor its asymmetrical orientation had an influence on the reflexive responses of the occupants. CONCLUSION: In summary, we did not find any significant differences in the reflex amplitude and delay of the neck musculature between drivers and front seat passengers. We therefore concluded that an increased risk of the driver sustaining WAD in frontal-oblique collisions, if it exists, cannot be due to differences in the reflexive responses.


Subject(s)
Accidents, Traffic , Neck Muscles/physiology , Adolescent , Adult , Biomechanical Phenomena , Electromyography , Female , Humans , Logistic Models , Male , Middle Aged , Whiplash Injuries/physiopathology , Young Adult
10.
Nat Ecol Evol ; 2(2): 325-333, 2018 02.
Article in English | MEDLINE | ID: mdl-29255301

ABSTRACT

Global change threatens invertebrate biodiversity and its central role in numerous ecosystem functions and services. Functional trait analyses have been advocated to uncover global mechanisms behind biodiversity responses to environmental change, but the application of this approach for invertebrates is underdeveloped relative to other organism groups. From an evaluation of 363 records comprising >1.23 million invertebrates collected from rivers across nine biogeographic regions on three continents, consistent responses of community trait composition and diversity to replicated gradients of reduced glacier cover are demonstrated. After accounting for a systematic regional effect of latitude, the processes shaping river invertebrate functional diversity are globally consistent. Analyses nested within individual regions identified an increase in functional diversity as glacier cover decreases. Community assembly models demonstrated that dispersal limitation was the dominant process underlying these patterns, although environmental filtering was also evident in highly glacierized basins. These findings indicate that predictable mechanisms govern river invertebrate community responses to decreasing glacier cover globally.


Subject(s)
Biodiversity , Global Warming , Ice Cover , Invertebrates/physiology , Rivers , Animals , Ecosystem , Europe , New Zealand , North America
11.
J Clin Microbiol ; 50(6): 1918-26, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22442325

ABSTRACT

A set of 300 Dutch Cryptococcus neoformans isolates, obtained from 237 patients during 1977 to 2007, was investigated by determining the mating type, serotype, and AFLP and microsatellite genotype and susceptibility to seven antifungal compounds. Almost half of the studied cases were from HIV-infected patients, followed by a patient group of individuals with other underlying diseases and immunocompetent individuals. The majority of the isolates were mating type α and serotype A, followed by αD isolates and other minor categories. The most frequently observed genotype was AFLP1, distantly followed by AFLP2 and AFLP3. Microsatellite typing revealed a high genetic diversity among serotype A isolates but a lower diversity within the serotype D set of isolates. One patient was infected by multiple AFLP genotypes. Fluconazole and flucytosine had the highest geometric mean MICs of 2.9 and 3.5 µg/ml, respectively, while amphotericin B (0.24 µg/ml), itraconazole (0.08 µg/ml), voriconazole (0.07 µg/ml), posaconazole (0.06 µg/ml), and isavuconazole (0.03 µg/ml) had much lower geometric mean MICs. One isolate had a high flucytosine MIC (>64 µg/ml), while decreased susceptibility (≥16 µg/ml) for flucytosine and fluconazole was found in 9 and 10 C. neoformans isolates, respectively.


Subject(s)
Cryptococcosis/epidemiology , Cryptococcosis/microbiology , Cryptococcus neoformans/classification , Cryptococcus neoformans/genetics , Genetic Variation , Molecular Typing , Mycological Typing Techniques , Adolescent , Adult , Aged , Aged, 80 and over , Antifungal Agents/pharmacology , Cryptococcus neoformans/isolation & purification , Female , HIV Infections/complications , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Molecular Epidemiology , Netherlands/epidemiology , Serotyping , Young Adult
12.
J Med Microbiol ; 60(Pt 10): 1487-1495, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21617022

ABSTRACT

A collection of 48 clinical Cryptococcus neoformans isolates from Croatia was investigated retrospectively using in vitro antifungal susceptibility testing and molecular biological techniques to determine mating type and serotype by PCR and amplified fragment length polymorphism (AFLP) genotyping. These isolates were obtained from 15 patients: ten were human immunodeficiency virus (HIV)-negative (66.7 %) and five were HIV-positive (33.3 %). From five patients, only one isolate was available, whilst from the other ten patients, two to 11 isolates were isolated sequentially. Antifungal susceptibility was tested by a broth microdilution method. Serotype A (genotype AFLP1) and serotype D (genotype AFLP2) were both found in six patients (40 % each), and serotype AD (genotype AFLP3) in three (20.0 %) patients. Mating type α (n = 12; 80.0 %) predominated and α/a hybrids were identified in 20.0 % of patients diagnosed with cryptococcosis. Two AFLP genotypes of C. neoformans were isolated during a single episode from one patient. The in vitro antifungal MIC(90) and susceptibility ranges for C. neoformans isolates were 0.5 µg ml(-1) (range 0.031-0.5 µg ml(-1)) for amphotericin B, 4 µg ml(-1) (range 1-4 µg ml(-1)) for flucytosine and fluconazole, 0.25 µg ml(-1) (range 0.031-0.5 µg ml(-1)) for itraconazole and 0.062 µg ml(-1) (range 0.031-0.25 µg ml(-1)) for voriconazole.


Subject(s)
Antifungal Agents/pharmacology , Cryptococcosis/microbiology , Cryptococcus neoformans/classification , Cryptococcus neoformans/drug effects , Molecular Typing , Mycological Typing Techniques , Adult , Aged , Amplified Fragment Length Polymorphism Analysis , Croatia , Cryptococcus neoformans/isolation & purification , Female , Genes, Mating Type, Fungal , Genotype , HIV Infections/complications , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Polymerase Chain Reaction , Retrospective Studies , Serotyping
13.
Plant Dis ; 92(12): 1650-1654, 2008 Dec.
Article in English | MEDLINE | ID: mdl-30764291

ABSTRACT

Leaf rust, caused by Puccinia triticina, is an important disease of durum wheat (Triticum turgidum subsp. durum) worldwide, and the most effective way to control it is through the use of resistant cultivars. A partially dominant leaf rust resistance gene present in the International Maize and Wheat Improvement Center-derived Chilean cv. Guayacan INIA and its sister line Guayacan 2 was mapped to chromosome arm 6BS by identifying linked amplified fragment length polymorphisms (AFLPs) and mapping two of the molecular markers in common wheat (T. aestivum) linkage maps of the International Triticeae Mapping Initiative and Oligoculm × Fukuho-komugi populations. Comparison of infection type responses of the two resistant durums with common wheat testers carrying the previously mapped resistance genes Lr36 and Lr53 on 6BS, and their chromosomal positions, indicated that the resistance gene in durum wheat Guayacan INIA is a new leaf rust resistance gene, which was designated as Lr61. Gene Lr61 is effective against the P. triticina race BBG/BN predominant in northwestern Mexico and other races infecting durum wheat in various countries.

14.
Plant Dis ; 92(3): 469-473, 2008 Mar.
Article in English | MEDLINE | ID: mdl-30769688

ABSTRACT

Leaf rust, caused by Puccinia triticina, is an important disease of durum wheat (Triticum turgidum subsp. durum) and only a few designated resistance genes are known to occur in this crop. A dominant leaf rust resistance gene in the Chilean durum cv. Llareta INIA was mapped to chromosome arm 7BL through bulked segregant analysis using the amplified fragment length polymorphism (AFLP) technique, and by mapping three polymorphic markers in the common wheat (T. aestivum) International Triticeae Mapping Initiative population. Several simple sequence repeat (SSR) markers, including Xgwm344-7B and Xgwm146-7B, were associated with the leaf rust resistance gene. Resistance response and chromosomal position indicated that this gene is likely to be Lr14a. The SSR markers Xgwm344-7B and Xgwm146-7B and one AFLP marker also differentiated common wheat cv. Thatcher from the near-isogenic line with Lr14a, as well as durum 'Altar C84' from durum wheat with Lr14a. This is the first report of the presence of Lr14a in durum wheat, although the gene originally was transferred from emmer wheat 'Yaroslav' to common wheat. Lr14a is also present in CIMMYT-derived durum 'Somateria' and effective against Mexican and other P. triticina races of durum origin. Lr14a should be deployed in combination with other effective leaf rust resistance genes to prolong its effectiveness in durum wheat.

15.
Genome ; 49(8): 977-90, 2006 Aug.
Article in English | MEDLINE | ID: mdl-17036073

ABSTRACT

Leaf (brown) and stripe (yellow) rusts, caused by Puccinia triticina and Puccinia striiformis, respectively, are fungal diseases of wheat (Triticum aestivum) that cause significant yield losses annually in many wheat-growing regions of the world. The objectives of our study were to characterize genetic loci associated with resistance to leaf and stripe rusts using molecular markers in a population derived from a cross between the rust-susceptible cultivar 'Avocet S' and the resistant cultivar 'Pavon76'. Using bulked segregant analysis and partial linkage mapping with AFLPs, SSRs and RFLPs, we identified 6 independent loci that contributed to slow rusting or adult plant resistance (APR) to the 2 rust diseases. Using marker information available from existing linkage maps, we have identified additional markers associated with resistance to these 2 diseases and established several linkage groups in the 'Avocet S' x 'Pavon76' population. The putative loci identified on chromosomes 1BL, 4BL, and 6AL influenced resistance to both stripe and leaf rust. The loci on chromosomes 3BS and 6BL had significant effects only on stripe rust, whereas another locus, characterized by AFLP markers, had minor effects on leaf rust only. Data derived from Interval mapping indicated that the loci identified explained 53% of the total phenotypic variation (R2) for stripe rust and 57% for leaf rust averaged across 3 sets of field data. A single chromosome recombinant line population segregating for chromosome 1B was used to map Lr46/Yr29 as a single Mendelian locus. Characterization of slow-rusting genes for leaf and stripe rust in improved wheat germplasm would enable wheat breeders to combine these additional loci with known slow-rusting loci to generate wheat cultivars with higher levels of slow-rusting resistance.


Subject(s)
Basidiomycota/pathogenicity , Triticum/genetics , Triticum/microbiology , Chromosome Mapping , Chromosomes, Plant/genetics , Crosses, Genetic , Genes, Plant , Genetic Markers , Lod Score , Phenotype , Plant Diseases/genetics , Plant Diseases/microbiology , Quantitative Trait Loci
16.
Theor Appl Genet ; 112(3): 500-8, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16331478

ABSTRACT

Resistance based on slow-rusting genes has proven to be a useful strategy to develop wheat cultivars with durable resistance to rust diseases in wheat. However this type of resistance is often difficult to incorporate into a single genetic background due to the polygenic and additive nature of the genes involved. Therefore, markers, both molecular and phenotypic, are useful tools to facilitate the use of this type of resistance in wheat breeding programs. We have used field assays to score for both leaf and yellow rust in an Avocet-YrA x Attila population that segregates for several slow-rusting leaf and yellow rust resistance genes. This population was analyzed with the AFLP technique and the slow-rusting resistance locus Lr46/Yr29 was identified. A common set of AFLP and SSR markers linked to the Lr46/Yr29 locus was identified and validated in other recombinant inbred families developed from single chromosome recombinant populations that segregated for Lr46. These populations segregated for leaf tip necrosis (LTN) in the field, a trait that had previously been associated with Lr34/Yr18. We show that LTN is also pleiotropic or closely linked to the Lr46/Yr29 locus and suggest that a new Ltn gene designation should be given to this locus, in addition to the one that already exists for Lr34/Yr18. Coincidentally, members of a small gene family encoding beta-1 proteasome subunits located on group 1L and 7S chromosomes implicated in plant defense were linked to the Lr34/Yr18 and Lr46/Yr29 loci.


Subject(s)
Basidiomycota/pathogenicity , Genes, Plant , Immunity, Innate/genetics , Plant Diseases/microbiology , Plant Leaves/microbiology , Proteasome Endopeptidase Complex/analysis , Chromosome Mapping , Chromosomes, Plant , Crosses, Genetic , DNA, Plant/isolation & purification , Expressed Sequence Tags , Genetic Markers , Microsatellite Repeats , Necrosis/pathology , Plant Diseases/genetics , Polymorphism, Single-Stranded Conformational , Proteasome Endopeptidase Complex/chemistry , Proteasome Endopeptidase Complex/genetics , Quantitative Trait Loci , Random Amplified Polymorphic DNA Technique
17.
Genome ; 48(1): 65-75, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15729398

ABSTRACT

A doubled-haploid (DH) population from an intervarietal cross between the Japanese cultivar 'Fukuho-komugi' and the Israeli wheat line 'Oligoculm' was produced by means of wheat x maize crosses. One hundred seven DH lines were genotyped to construct a simple sequence repeat (SSR) based linkage map with RFLP, RAPD, and inter-simple sequence repeat markers. Out of 570 loci genotyped, 330 were chosen based on their positions on the linkage map to create a "framework" map for quantitative trait locus (QTL) analysis. Among the 28 linkage groups identified, 25 were assigned to the 21 chromosomes of wheat. The total map length was 3948 cM, including the three unassigned linkage groups (88 cM), and the mean interval between loci was 12.0 cM. Loci with segregation distortion were clustered on chromosomes 1A, 4B, 4D, 5A, 6A, 6B, and 6D. After vernalization, the DH lines were evaluated for spike number per plant (SN) and spike length (SL) in a greenhouse under 24-h daylength to assess the "gigas" features (extremely large spikes and leaves) of 'Oligoculm'. The DH lines were also autumn-sown in the field in two seasons (1990-1991 and 1997-1998) for SN and SL evaluation. QTL analysis was performed by composite interval mapping (CIM) with the framework map to detect QTLs for SN and SL. A major QTL on 1AS, which was stable in both greenhouse and field conditions, was found to control SN. This QTL was close to the glume pubescence locus (Hg) and explained up to 62.9% of the total phenotypic variation. The 'Oligoculm' allele restricted spike number. The SSR locus Xpsp2999 was the closest locus to this QTL and is considered to be a possible marker for restricted tillering derived from 'Oligoculm'. Eight QTLs were detected for SL. The largest QTL detected on 2DS was common to the greenhouse and field environments. It explained up to 33.3% of the total phenotypic variation. The second largest QTL on 1AS was common to the greenhouse and the 1997-1998 season. The position of this QTL was close to that for the SN detected on 1AS. The association between SN and SL is discussed.


Subject(s)
Chromosome Mapping , Haploidy , Microsatellite Repeats , Quantitative Trait Loci/genetics , Triticum/genetics
19.
Phytopathology ; 93(7): 881-90, 2003 Jul.
Article in English | MEDLINE | ID: mdl-18943170

ABSTRACT

ABSTRACT Leaf rust and stripe rust, caused by Puccinia triticina and P. striiformis, respectively, are important diseases of wheat in many countries. In this study we sought to identify molecular markers for adult plant resistance genes that could aid in incorporating such durable resistance into wheat. We used a doubled haploid population from a Japanese cv. Fukuho-komugi x Israeli wheat Oligoculm cross that had segregated for resistance to leaf rust and stripe rust in field trials. Joint and/or single-year analyses by composite interval mapping identified two quantitative trait loci (QTL) that reduced leaf rust severity and up to 11 and 7 QTLs that might have influenced stripe rust severity and infection type, respectively. Four common QTLs reduced stripe rust severity and infection type. Except for a QTL on chromosome 7DS, no common QTL for leaf rust and stripe rust was detected. QTL-7DS derived from 'Fukuho-komugi' had the largest effect on both leaf rust and stripe rust severities, possibly due to linked resistance genes Lr34/Yr18. The microsatellite locus Xgwm295.1, located almost at the peak of the likelihood ratio contours for both leaf and stripe rust severity, was closest to Lr34/Yr18. QTLs located on 1BL for leaf rust severity and 3BS for stripe rust infection type were derived from 'Oligoculm' and considered to be due to genes Lr46 and Yr30, respectively. Most of the remaining QTLs for stripe rust severity or infection type had smaller effects. Our results indicate there is significant diversity for genes that have minor effects on stripe rust resistance, and that successful detection of these QTLs by molecular markers should be helpful both for characterizing wheat genotypes effectively and combining such resistance genes.

20.
Genome ; 40(2): 253-60, 1997 Apr.
Article in English | MEDLINE | ID: mdl-18464825

ABSTRACT

Leaf rust, caused by Puccinia recondita Rob. ex Desm., is a common disease in wheat. The objective of this study was to develop molecular markers associated with the quantitative trait loci (QTLs) putatively conferring durable leaf rust resistance in Triticum aestivum L. em. Thell. A population of 77 recombinant inbred lines (RILs) developed from 'Parula' (resistant) and 'Siete Cerros' (moderately susceptible) was used. Bulked segregant analysis was done using random amplified polymorphic DNAs (RAPDs) with DNA enriched for low-copy sequences using hydroxyapatite chromatography. Out of 400 decamer primers screened, 3 RAPD markers were identified between the bulk of the most resistant and the bulk of the most susceptible lines. These were cloned and used as probes on the RILs in Southern hybridizations. Two probes revealed two tightly linked loci. One-way analysis of variance showed that these two loci, and another revealed by the third probe, were linked to QTLs controlling leaf rust resistance based on data taken from 2 years of replicated field trials. Cytogenetic analysis placed the two tightly linked loci on the long arm of chromosome 7B. The third probe detected loci located on the short arms of chromosomes 1B and 1D. It is suggested that the QTL detected on 7BL may well be homoeoallelic to Lr34.

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