Root Interactions in a Maize/Soybean Intercropping System Control Soybean Soil-Borne Disease,Red Crown Rot

Background

Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control.

Principal Findings

In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum). The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro.

Conclusions

To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices.     

Structure Reveals Regulatory Mechanisms of a MaoC-Like Hydratase from Phytophthora capsici Involved in Biosynthesis of Polyhydroxyalkanoates (PHAs)

Background

Polyhydroxyalkanoates (PHAs) have attracted increasing attention as “green plastic” due to their biodegradable, biocompatible, thermoplastic, and mechanical properties, and considerable research has been undertaken to develop low cost/high efficiency processes for the production of PHAs. MaoC-like hydratase (MaoC), which belongs to (R)-hydratase involved in linking the β-oxidation and the PHA biosynthetic pathways, has been identified recently. Understanding the regulatory mechanisms of (R)-hydratase catalysis is critical for efficient production of PHAs that promise synthesis an environment-friendly plastic.

Methodology/Principal Findings

We have determined the crystal structure of a new MaoC recognized from Phytophthora capsici. The crystal structure of the enzyme was solved at 2.00 Å resolution. The structure shows that MaoC has a canonical (R)-hydratase fold with an N-domain and a C-domain. Supporting its dimerization observed in structure, MaoC forms a stable homodimer in solution. Mutations that disrupt the dimeric MaoC result in a complete loss of activity toward crotonyl-CoA, indicating that dimerization is required for the enzymatic activity of MaoC. Importantly, structure comparison reveals that a loop unique to MaoC interacts with an α-helix that harbors the catalytic residues of MaoC. Deletion of the loop enhances the enzymatic activity of MaoC, suggesting its inhibitory role in regulating the activity of MaoC.

Conclusions/Significance

The data in our study reveal the regulatory mechanism of an (R)-hydratase, providing information on enzyme engineering to produce low cost PHAs.     

Influence of spatial arrangement in maize-soybean intercropping on root growth and water use efficiency

Background and aims

The relationship between transpiration and root distribution under different spatial arrangements of intercropping is poorly understood. The effects of three spatial arrangements in the maize (Zea mays L.) - soybean (Glycine max L.) intercropping on root distribution, transpiration, water use efficiency (WUE) and grain yield were examined.

Methods

Two-year field experiments were conducted using three spatial arrangements of 2 rows maize × 4 rows soybean (M2S4), 2 rows maize × 2 rows soybean (M2S2) and 4 rows maize × 2 rows soybean (M4S2), with their respective sole crops (monocrop) for comparison.

Results

The grain yield of maize in intercrops was higher than its monocrop and that of soybean in intercrops was lower than its monocrop. Except for M2S2 in 2014, there were yield advantages in intercropping due to improvement in the land use efficiency. Transpiration in maize was higher than in soybean regardless of the spatial arrangements. Transpiration of both maize and soybean was influenced by the spatial arrangements of the intercropping with M4S2 or M2S4 tending to have higher daily transpiration than monocrops and other spatial arrangements. Intercropping enhanced root length density (RLD) in both maize and soybean compared to the corresponding monocrop. RLD was higher and land equivalent ratio (LER) was lower under M2S2 than under other spatial arrangements of intercropping, WUE was higher in M4S2 than in other spatial arrangements.

Conclusions

Intercropping was more efficient in using the environmental resources than monocropping. The M4S2 spatial arrangement in the maize-soybean intercropping could be selected because of its sustainability and greater land and water use efficiency.

     

Survival and spread of Phytophthora capsici on Long Island, New York

Phytophthora capsici is an oomycete soil-borne plant pathogen that causes root, fruit and foliar disease on a variety of vegetables. The epidemiology and population structure varies depending on the region surveyed and our objective was to investigate survival and spread on farms on Long Island, New York using single nucleotide polymorphism (SNP) markers. A total of 373 P. capsici isolates were collected from pumpkin, pepper, watermelon and snap bean on 15 farms. Both mating type were recovered from most locations. Genotypic analysis was conducted using 14 SNP loci located primarily within genes. A total of 128 unique multi-locus genotypes were identified. Of these, 54 appear to be clonal lineages ranging in size from 2 to 26 members. Most clonal lineages were recovered during the same year. Our results indicate that both sexual and clonal reproduction play important roles in the epidemiology of P. capsici on Long Island, NY, USA. The implications for managing the disease are discussed.     

Combined use of bulked segregant analysis and microarrays reveals SNP markers pinpointing a major QTL for resistance to Phytophthora capsici in pepper

Key message

Bulked segregant analysis (BSA) using Affymetrix GeneChips revealed candidate genes underlying the major QTL for Phytophthora capsici resistance in Capsicum . Using the candidate genes, reliable markers for Phytophthora resistance were developed and validated.

Abstract

Phytophthora capsici L. is one of the most destructive pathogens of pepper (Capsicum spp.). Resistance of pepper against P. capsici is controlled by quantitative trait loci (QTL), including a major QTL on chromosome 5 that is the predominant contributor to resistance. Here, to maximize the effect of this QTL and study its underlying genes, an F₂ population and recombinant inbred lines were inoculated with P. capsici strain JHAI1-7 zoospores at a low concentration (3 × 10³/mL). Resistance phenotype segregation ratios for the populations fit a 3:1 and 1:1 (resistant:susceptible) segregation model, respectively, consistent with a single dominant gene model. Bulked segregant analysis (BSA) using Affymetrix GeneChips revealed a single position polymorphism (SPP) marker mapping to the major QTL. When this SPP marker (Phyto5SAR) together with other SNP markers located on chromosome 5 was used to confirm the position of the major QTL, Phyto5SAR showed the highest LOD value at the QTL. A scaffold sequence (scaffold194) containing Phyto5SAR was identified from the C. annuum genome database. The scaffold contained two putative NBS-LRR genes and one SAR 8.2A gene as candidates for contributing to P. capsici resistance. Markers linked to these genes were developed and validated by testing 100 F₁ commercial cultivars. Among the markers, Phyto5NBS1 showed about 90 % accuracy in predicting resistance phenotypes to a low-virulence P. capsici isolate. These results suggest that Phyto5NBS1 is a reliable marker for P. capsici resistance and can be used for identification of a gene(s) underlying the major QTL on chromosome 5.     

Evaluation of the Efficacy & Biochemical Mechanism of Cell Death Induction by Piper longum Extract Selectively in In-Vitro and In-Vivo Models of Human Cancer Cells

Background

Currently chemotherapy is limited mostly to genotoxic drugs that are associated with severe side effects due to non-selective targeting of normal tissue. Natural products play a significant role in the development of most chemotherapeutic agents, with 74.8% of all available chemotherapy being derived from natural products.

Objective

To scientifically assess and validate the anticancer potential of an ethanolic extract of the fruit of the Long pepper (PLX), a plant of the piperaceae family that has been used in traditional medicine, especially Ayurveda and investigate the anticancer mechanism of action of PLX against cancer cells.

Materials & Methods

Following treatment with ethanolic long pepper extract, cell viability was assessed using a water-soluble tetrazolium salt; apoptosis induction was observed following nuclear staining by Hoechst, binding of annexin V to the externalized phosphatidyl serine and phase contrast microscopy. Image-based cytometry was used to detect the effect of long pepper extract on the production of reactive oxygen species and the dissipation of the mitochondrial membrane potential following Tetramethylrhodamine or 5,5,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine chloride staining (JC-1). Assessment of PLX in-vivo was carried out using Balb/C mice (toxicity) and CD-1 nu/nu immunocompromised mice (efficacy). HPLC analysis enabled detection of some primary compounds present within our long pepper extract.

Results

Our results indicated that an ethanolic long pepper extract selectively induces caspase-independent apoptosis in cancer cells, without affecting non-cancerous cells, by targeting the mitochondria, leading to dissipation of the mitochondrial membrane potential and increase in ROS production. Release of the AIF and endonuclease G from isolated mitochondria confirms the mitochondria as a potential target of long pepper. The efficacy of PLX in in-vivo studies indicates that oral administration is able to halt the growth of colon cancer tumors in immunocompromised mice, with no associated toxicity. These results demonstrate the potentially safe and non-toxic alternative that is long pepper extract for cancer therapy.     

Practitioner Perspectives on Strategies to Promote Longer-Term Benefits of Acupuncture or Counselling for Depression: A Qualitative Study

Background

Non-pharmacological interventions for depression may help patients manage their condition. Evidence from a recent large-scale trial (ACUDep) suggests that acupuncture and counselling can provide longer-term benefits for many patients with depression. This paper describes the strategies practitioners reported using to promote longer-term benefits for their patients.

Methods

A qualitative sub-study of practitioners (acupuncturists and counsellors) embedded in a randomised controlled trial. Using topic guides, data was collected from telephone interviews and a focus group, altogether involving 19 counsellors and 17 acupuncturists. Data were audio recorded, transcribed verbatim and analysed using thematic content analysis.

Results

For longer-term impact, both acupuncturists and counsellors encouraged insight into root causes of depression on an individual basis and saw small incremental changes as precursors to sustained benefit. Acupuncturists stressed the importance of addressing concurrent physical symptoms, for example helping patients relax or sleep better in order to be more receptive to change, and highlighted the importance of Chinese medicine theory-based lifestyle change for lasting benefit. Counsellors more often highlighted the importance of the therapeutic relationship, emphasising the need for careful “pacing” such that the process and tools employed were tailored and timed for each individual, depending on the “readiness” to change. Our data is limited to acupuncture practitioners using the principles of traditional Chinese medicine, and counsellors using a humanistic, non-directive and person-centred approach.

Conclusions

Long-term change appears to be an important focus within the practices of both acupuncturists and counsellors. To achieve this, practitioners stressed the need for an individualised approach with a focus on root causes.     

Association between Socioeconomic Position and Tuberculosis in a Large Population-Based Study in Rural Malawi

Setting

There is increasing interest in social structural interventions for tuberculosis. The association between poverty and tuberculosis is well established in many settings, but less clear in rural Africa. In Karonga District, Malawi, we found an association between higher socioeconomic status and tuberculosis from 1986-1996, independent of HIV status and other factors.

Objective

To investigate the relationship in the same area in 1997-2010.

Design

All adults in the district with new laboratory-confirmed tuberculosis were included. They were compared with community controls, selected concurrently and frequency-matched for age, sex and area.

Results

1707 cases and 2678 controls were interviewed (response rates >95%). The odds of TB were increased in those working in the cash compared to subsistence economy (p<0.001), and with better housing (p-trend=0.006), but decreased with increased asset ownership (p-trend=0.003). The associations with occupation and housing were partly mediated by HIV status, but remained significant.

Conclusion

Different socioeconomic measures capture different pathways of the association between socioeconomic status and tuberculosis. Subsistence farmers may be relatively unexposed whereas those in the cash economy travel more, and may be more likely to come forward for diagnosis. In this setting “better houses” may be less well ventilated and residents may spend more time indoors.     

Evidence of genetically diverse virulent mating types of <Emphasis Type="Italic">Phytophthora capsici</Emphasis> from <Emphasis Type="Italic">Capsicum annum</Emphasis> L.

Chili pepper (Capsicum annum L.) is an important economic crop that is severely destroyed by the filamentous oomycete Phytophthora capsici. Little is known about this pathogen in key chili pepper farms in Punjab province, Pakistan. We investigated the genetic diversity of P. capsici strains using standard taxonomic and molecular tools, and characterized their colony growth patterns as well as their disease severity on chili pepper plants under the greenhouse conditions. Phylogenetic analysis based on ribosomal DNA (rDNA), β-tubulin and translation elongation factor 1α loci revealed divergent evolution in the population structure of P. capsici isolates. The mean oospore diameter of mating type A1 isolates was greater than that of mating type A2 isolates. We provide first evidence of an uneven distribution of highly virulent mating type A1 and A2 of P. capsici that are insensitive to mefenoxam, pyrimorph, dimethomorph, and azoxystrobin fungicides, and represent a risk factor that could ease outpacing the current P. capsici management strategies.     

Challenges in the Care of Clients with Established Cardiovascular Disease: Lessons Learned from Australian Community Pharmacists

Background

As primary healthcare professionals, community pharmacists have both opportunity and potential to contribute to the prevention and progression of chronic diseases. Using cardiovascular disease (CVD) as a case study, we explored factors that influence community pharmacists’ everyday practice in this area. We also propose a model to best illustrate relationships between influencing factors and the scope of community pharmacy practice in the care of clients with established CVD.

Methods

In-depth, semi-structured interviews were conducted with 21 community pharmacists in New South Wales, Australia. All interviews were audio-recorded, transcribed ad verbatim, and analysed using a “grounded-theory” approach.

Results

Our model shows that community pharmacists work within a complex system and their practice is influenced by interactions between three main domains: the “people” factors, including their own attitudes and beliefs as well as those of clients and doctors; the “environment” within and beyond the control of community pharmacy; and outcomes of their professional care. Despite the complexity of factors and interactions, our findings shed some light on the interrelationships between these various influences. The overarching obstacle to maximizing the community pharmacists’ contribution is the lack of integration within health systems. However, achieving better integration of community pharmacists in primary care is a challenge since the systems of remuneration for healthcare professional services do not currently support this integration.

Conclusion

Tackling chronic diseases such as CVD requires mobilization of all sources of support in the community through innovative policies which facilitate inter-professional collaboration and team care to achieve the best possible healthcare outcomes for society.     

MET Gene Copy Number Predicts Worse Overall Survival in Patients with Non-Small Cell Lung Cancer (NSCLC); A Systematic Review and Meta-Analysis

Objectives

MET is a receptor present in the membrane of NSCLC cells and is known to promote cell proliferation, survival and migration. MET gene copy number is a common genetic alteration and inhibition o MET emerges as a promising targeted therapy in NSCLC. Here we aim to combine in a meta-analysis, data on the effect of high MET gene copy number on the overall survival of patients with resected NSCLC.

Methods

Two independent investigators applied parallel search strategies with the terms “MET AND lung cancer”, “MET AND NSCLC”, “MET gene copy number AND prognosis” in PubMed through January 2014. We selected the studies that investigated the association of MET gene copy number with survival, in patients who received surgery.

Results

Among 1096 titles that were identified in the initial search, we retrieved 9 studies on retrospective cohorts with adequate retrievable data regarding the prognostic impact of MET gene copy number on the survival of patients with NSCLC. Out of those, 6 used FISH and the remaining 3 used RT PCR to assess the MET gene copy number in the primary tumor. We calculated the I² statistic to assess heterogeneity (I² = 72%). MET gene copy number predicted worse overall survival when all studies were combined in a random effects model (HR = 1.78, 95% CI 1.22–2.60). When only the studies that had at least 50% of adenocarcinoma patients in their populations were included, the effect was significant (five studies, HR 1.55, 95% CI 1.23–1.94). This was not true when we included only the studies with no more than 50% of the patients having adenocarcinoma histology (four studies HR 2.18, 95% CI 0.97–4.90).

Conclusions

Higher MET gene copy number in the primary tumor at the time of diagnosis predicts worse outcome in patients with NSCLC. This prognostic impact may be adenocarcinoma histology specific.     

Does KRAS Testing in Metastatic Colorectal Cancer Impact Overall Survival? A Comparative Effectiveness Study in a Population-Based Sample

Purpose

Epidermal growth factor receptor (EGFR) inhibitors are approved for treating metastatic colorectal cancer (CRC); KRAS mutation testing is recommended prior to treatment. We conducted a non-inferiority analysis to examine whether KRAS testing has impacted survival in CRC patients.

Patients and Methods

We included 1186 metastatic CRC cases from seven health plans. A cutpoint of July, 2008, was used to define two KRAS testing time period groups: “pre-testing” (n = 760 cases) and “post-testing” (n = 426 cases). Overall survival (OS) was estimated, and the difference in median OS between the groups was calculated. The lower bound of the one-sided 95% confidence interval (CI) for the difference in survival was used to test the null hypothesis of post-testing inferiority. Multivariable Cox regression models were constructed to adjust for covariates.

Results

The median unadjusted OS was 15.4 months (95% CI: 14.0–17.5) and 12.8 months (95% CI: 10.0–15.2) in the pre- and post-testing groups, respectively. The OS difference was −2.6 months with one-sided 95% lower confidence bound of −5.13 months, which was less than the non-inferiority margin (−5.0 months, unadjusted p = 0.06), leading to a failure to reject inferiority of OS in the post-testing period. In contrast, in the adjusted analysis, OS non-inferiority was identified in the post-testing period (p = 0.001). Sensitivity analyses using cutpoints before and after July, 2008, also met the criteria for non-inferiority.

Conclusion

Implementation of KRAS testing did not influence CRC OS. Our data support the use of KRAS testing to guide administration of EGFR inhibitors for treatment of metastatic CRC without diminished OS.     

Curcuma longa Extract Associated with White Pepper Lessens High Fat Diet-Induced Inflammation in Subcutaneous Adipose Tissue

Background

Supra-nutritional doses of curcumin, derived from the spice Curcuma longa, have been proposed as a potential treatment of inflammation and metabolic disorders related to obesity. The aim of the present study was to test whether Curcuma longa extract rich in curcumin and associated with white pepper (Curcuma-P®), at doses compatible with human use, could modulate systemic inflammation in diet-induced obese mice. We questioned the potential relevance of changes in adiposity and gut microbiota in the effect of Curcuma-P® in obesity.

Methodology/Principal Findings

Mice were fed either a control diet (CT), a high fat (HF) diet or a HF diet containing Curcuma longa extract (0.1 % of curcumin in the HF diet) associated with white pepper (0.01 %) for four weeks. Curcumin has been usually combined with white pepper, which contain piperine, in order to improve its bioavailability. This combination did not significantly modify body weight gain, glycemia, insulinemia, serum lipids and intestinal inflammatory markers. Tetrahydrocurcumin, but not curcumin accumulated in the subcutaneous adipose tissue. Importantly, the co-supplementation in curcuma extract and white pepper decreased HF-induced pro-inflammatory cytokines expression in the subcutaneous adipose tissue, an effect independent of adiposity, immune cells recruitment, angiogenesis, or modulation of gut bacteria controlling inflammation.

Conclusions/Significance

These findings support that nutritional doses of Curcuma longa, associated with white pepper, is able to decrease inflammatory cytokines expression in the adipose tissue and this effect could be rather linked to a direct effect of bioactive metabolites reaching the adipose tissue, than from changes in the gut microbiota composition.     

Psychometric Properties of the Hebrew Translation of the Patient Activation Measure (PAM-13)

Objective

“Patient activation” reflects involvement in managing ones health. This cross-sectional study assessed the psychometric properties of the Hebrew translation (PAM-H) of the PAM-13.

Methods

A nationally representative sample of 203 Hebrew-speaking Israeli adults answered the PAM-H, PHQ-9 depression scale, SF-12, and Self-efficacy Scale via telephone.

Results

Mean PAM-H scores were 70.7±15.4. Rasch analysis indicated that the PAM-H is a good measure of activation. There were no differences in PAM-H scores based on gender, age or education. Subjects with chronic disease scored lower than those without. Scores correlated with the Self-efficacy Scale (0.47), Total SF-12 (0.39) and PHQ-9 (−0.35, P<0.0001), indicating concurrent validity. Discriminant validity was reflected by a significant difference in the mean PAM-H score of those who scored below 10 (72.1±14.8) on the PHQ-9 (not depressed) compared to those scoring ≥10 (i.e. probable depression) (59.2±15.8; t 3.75; P = 0.001).

Conclusion

The PAM-H psychometric properties indicate its usefulness with the Hebrew-speaking Israeli population.

Practice Implications

PAM-H can be useful for assessing programs aimed at effecting changes in patient compliance, health behaviors, etc. Researchers in Israel should use a single translation of the PAM-13 so that findings can be compared, increasing understanding of patient activation.     

Greenhouse and field evaluations of potassium phosphonate: the control of Phytophthora foot rot of black pepper in Vietnam

Phytophthora foot rot of black pepper caused by Phytophthora capsici is a major disease of black pepper throughout production areas in Vietnam. The disease causes collar, foot and tap root rots and eventual death of the infected vine. Potassium phosphonate was evaluated for the control of this disease in greenhouse and field trials. In greenhouse trials three-month-old vines treated with phosphonate by soil drenching (10–20 g a.i./l) and then inoculated with P. capsici mycelium (2% v/v soil) had significantly less foot rot compared to vines grown in non-treated soil. In field trials mature vines were treated with phosphonate at 50–100 g a.i/pole soil drenching or 10 g a.i./l by root infusion. After 10 days root, stem and leaf specimens were removed for bioassay by inoculation with 5 ml of P. capsici zoospores suspension (10⁶–10⁸ spores/ml). Soil drenching with phosphonate inhibited the colonisation of pathogen on excised leaf, stem and root tissues, significantly more than phosphonate root infusion. Our study provides further evidence supporting the efficacy of potassium phosphonate in the management of black pepper foot rot caused by P. capsici. The excised leaf and stem bioassay used in this study is a rapid and useful technique for testing the efficacy of systemic fungicides in controlling this disease.     

Biocontrol activity and root colonization by Pseudomonas corrugata strains CCR04 and CCR80 against Phytophthora blight of pepper

Previously, we selected Pseudomonas corrugata strains CCR04 and CCR80 as rhizobacteria suppressive to Phytophthora blight of pepper caused by Phytophthora capsici. In this study, we investigated soil microbial activity in pepper plants root-drenched with strains CCR04 and CCR80 in relation to their biocontrol activity, root colonization by using bacterial population counts and scanning electron microscopy, biofilm formation and cell motility as well as cell sensitivity to hydrogen peroxide (H₂O₂). As a result, strains CCR04 and CCR80 more effectively suppressed disease expression in pepper plants through root colonization than did Paenibacillus polymyxa AC-1 (positive control), Escherichia coli DH5α (negative control) or MgSO₄ solution (untreated control). Strains CCR04 and CCR80 had efficient biofilm formation and cell motility (swimming and swarming activities) abilities and responded to certain tested compounds (amino acids, organic acids and sugars), which can be found in root exudates. Strains CCR04 and CCR80 and the positive control strain AC-1 were relatively insensitive to H₂O₂, a reactive oxidative species at concentration up to 20 mM, unlike the negative control strain DH5α. Taken together, these results suggest that P. corrugata CCR04 and CCR80 can effectively inhibit P. capsici infection of pepper plants through successful colonization of plant roots. This bacterial colonization may be facilitated by the biofilm formation ability and cell motility in addition to reduced sensitivity to H₂O₂ and probably the production of antimicrobial compounds. These findings highlight the potential of strains CCR04 and CCR80 as biocontrol agents for the management of Phytophthora blight of pepper.     

Economic Impact of Maternal Death on Households in Rural China: A Prospective Cohort Study

Objective

To assess the economic impact of maternal death on rural Chinese households during the year after maternal death.

Methods

A prospective cohort study matched 183 households who had suffered a maternal death to 346 households that experienced childbirth without maternal death in rural areas of three provinces in China. Surveys were conducted at baseline (1–3 months after maternal death or childbirth) and one year after baseline using the quantitative questionnaire. We investigated household income, expenditure, accumulated debts, and self-reported household economic status. Difference-in-Difference (DID), linear regression, and logistic regression analyses were used to compare the economic status between households with and without maternal death.

Findings

The households with maternal death had a higher risk of self-reported “household economy became worse” during the follow-up period (adjusted OR = 6.04, p<0.001). During the follow-up period, at the household level, DID estimator of income and expenditure showed that households with maternal death had a significant relative reduction of US$ 869 and US$ 650, compared to those households that experienced childbirth with no adverse event (p<0.001). Converted to proportions of change, an average of 32.0% reduction of annual income and 24.9% reduction of annual expenditure were observed in households with a maternal death. The mean increase of accumulated debts in households with a maternal death was 3.2 times as high as that in households without maternal death (p = 0.024). Expenditure pattern of households with maternal death changed, with lower consumption on food (p = 0.037), clothes and commodity (p = 0.003), traffic and communication (p = 0.022) and higher consumption on cigarette or alcohol (p = 0.014).

Conclusion

Compared with childbirth, maternal death had adverse impact on household economy, including higher risk of self-reported “household economy became worse”, decreased income and expenditure, increased debts and changed expenditure pattern.     

Development of an Improved Isolation Approach and Simple Sequence Repeat Markers To Characterize Phytophthora capsici Populations in Irrigation Ponds in Southern Georgia

Phytophthora capsici, the causal agent of Phytophthora blight, is a major concern in vegetable production in Georgia and many other states in the United States. Contamination of irrigation water sources by P. capsici may be an important source of inoculum for the pathogen. A simple method was developed in this study to improve the efficiency of recovering P. capsici from fruits used as baits in irrigation ponds. In contrast to direct isolation on agar plates, infected fruit tissues were used to inoculate stems of pepper seedlings, and the infected pepper stems were used for isolation on agar plates. With isolation through inoculation of pepper stems, the frequency of recovering P. capsici from infected eggplant and pear fruits increased from 13.9% to 77.7% and 8.1% to 53.5%, respectively, compared with direct isolation on agar plates. P. capsici was isolated from seven out of nine irrigation ponds evaluated, with most of the ponds containing both A1 and A2 mating types and a 4:5 ratio of A1 to A2 when isolates from all ponds were calculated. All P. capsici isolates were pathogenic on squash plants, and only a small proportion (8.2%) of the isolates were resistant or intermediately sensitive to mefenoxam. Simple sequence repeats (SSRs) were identified through bioinformatics mining of 55,848 publicly available expressed sequence tags of P. capsici in dbEST GenBank. Thirty-one pairs of SSR primers were designed, and SSR analysis indicated that the 61 P. capsici isolates from irrigation ponds were genetically distinct. Cluster analysis separated the isolates into five genetic clusters with no more than two genetic groups in one pond, indicating relatively low P. capsici genetic diversity in each pond. The isolation method and SSR markers developed for P. capsici in this study could contribute to a more comprehensive understanding of the genetic diversity of this important pathogen.Phytophthora capsici, the causal agent of Phytophthora blight, is a widespread and destructive plant pathogen that causes root rot, crown rot, fruit rot, and foliar blight on many economically important crops in the United States and throughout the world (1). A number of important vegetable crops are susceptible to this pathogen, including peppers, squash, cucumber, watermelon, cantaloupe, zucchini, eggplant, pumpkin, tomatoes, and snap beans. The pathogen causes significant yield reductions and quality losses to vegetable industries and has become a major concern in vegetable production in the United States in recent years. The efficacies of current strategies for management of the disease are limited. No single fungicide has consistently and effectively suppressed losses caused by P. capsici epidemics. While fungicides containing the active ingredient mefenoxam provide some level of control of P. capsici, mefenoxam-resistant isolates that challenge the usefulness of the compound have developed (3, 8).It is critical to understand the ecology and epidemiology of P. capsici in order to design more effective disease management strategies. Studies conducted in recent years indicate that P. capsici survives in irrigation water in the United States, and irrigation water may serve as an important inoculum source. Roberts et al. (14) reported that P. capsici was isolated from tailwater (surface runoff water) in Florida using water filtration and lemon leaf baiting techniques. Gevens et al. (3) used pear and cucumber fruits as baits and isolated P. capsici from irrigation water sources in Michigan. It was unknown, however, if irrigation water sources in Georgia could be significant sources of primary inoculum. Earlier studies using water filtration or direct isolation from water and bottom sediment did not identify P. capsici in surface irrigation ponds in Georgia (16).Since surface water can be a significant source of P. capsici, it is critical to use appropriate methods to isolate the pathogen from irrigation water and to facilitate characterization of the isolates. Fruit, especially pears, is often used as bait to recover Phytophthora spp. from water (3, 21). In comparison to water filtration, the baiting technique is easier and less labor intensive. However, direct isolation from infected fruit bait is often hampered by other microorganisms. Isolation of Phytophthora spp. is often affected by Pythium spp. that overgrow fruit and agar plates. Hence, development of a more efficient isolation method is needed to increase the frequency of P. capsici recovery to facilitate the detection and characterization of isolates associated with water sources.The objectives of this study were to develop an efficient method to isolate P. capsici from irrigation ponds in southern Georgia and to develop simple sequence repeat (SSR) markers to analyze the genetic diversity of P. capsici populations in irrigation ponds. SSRs are tandemly repeated motifs of 1 to 6 bases found in the nuclear genomes of all eukaryotic organisms and are often abundant and evenly dispersed (7). They are highly polymorphic, multiallelic, and codominant and are believed to be a more efficient marker system than restriction fragment length polymorphisms and randomly amplified polymorphic DNAs (18, 23). SSR markers have been derived from publicly available expressed sequence tags (ESTs) of a few plant pathogens, including Phytophthora infestans, Phytophthora sojae, and Magnaporthe grisea (5, 10, 23); however, no SSRs for P. capsici have been developed. Development of EST-SSR markers may provide an effective molecular marker system for analysis of genetic variation within P. capsici populations.