Modelling morphological and physiological responses of tomato introgression lines to drought stress

Tomato (Solanum lycopersicum L.) is a major vegetable crop grown in both outdoor fields and greenhouses. Water shortage is a significant problem in field-grown tomatoes. Genetic variation in the adaptation strategies to water shortage influences the differing water use and agronomic performances, in connection to varying climatic factors. Understanding the mechanisms of the adaptation to water deficit in the context of genetic implications is needed for better management and crop improvement. This work aims at investigating the adaptation mechanism of tomato to water deficit under a set of climatic condition, identifying the associated genome regions involved in the adaption, and predicting and evaluating the agronomic performances of virtual ILs in different climatic scenarios. This study was conducted using 50 tomato introgression lines (ILs) and two parent lines S. pennellii and S. lycopersicum cv. M82, in greenhouse conditions. Terminal drought stress was given at seven 7th leaf stage. There was a high (R2= 0.67 -0.75) causal relationships between unstressed and stressed performances for leaf areas increased, water transpired and shoot dry mass produced. The change in plasticity of shoot dry weight was mainly explained by that of leaf area while plasticity of cumulative transpiration was mainly attributed to that of specific transpiration. With the input of unstressed values and QTL-derived parameters from the response to water shortage of leaf expansion and stomatal conductance, stressed transpiration of all ILs was well predicted with high accuracy within the tested vapour pressure deficit ranges. With the implications of climatic factors, genotype-specific parameters (including drought reaction ones) were incorporated into an eco-physiological model, which consisted of three modules mainly for leaf growth, transpiration and dry matter production. With or without the inputs of leaf area and soil water, model performance was evaluated separately for target agronomic traits. The aggregated model could have well predicted the unstressed performances of leaf area, transpiration, shoot dry matter (accuracy = 0.69 - 0.84) and the fraction of transpirable soil water under stress (accuracy = 0.66). However, there was 20 to 30% of overestimation for the stressed performance (accuracy = 0.55 - 0.77). With the input of leaf area, the model performance was much improved for total water transpired and soil water. The genome-based eco-physiological model worked well as a tool to predict the stressed agronomic performances of tomato introgression lines.Die Tomate (Solanum lycopersicum L.) ist eine wichtige Gemüsepflanze, die sowohl im Freiland als auch in Gewächshäusern angebaut wird. Wasserknappheit ist ein bedeutendes Problem bei Freiland-Tomaten. Genetische Unterschiede in den Anpassungsstrategien an den Wassermangel beeinflussen den unterschiedlichen Wasserverbrauch und die agronomischen Leistungen in Verbindung mit unterschiedlichen klimatischen Faktoren. Das Verständnis der Mechanismen der Anpassung an Wassermangel im Zusammenhang mit den genetischen Implikationen ist für ein besseres Management und eine Verbesserung der Kulturpflanzen erforderlich. Diese Arbeit zielte darauf ab, den Anpassungsmechanismus von Tomaten an Wassermangel unter einer Reihe von klimatischen Bedingungen zu untersuchen, die damit verbundenen Genomregionen , die in die Anpassung einbezogen sind zu identifizieren, und die agronomischen Leistungen virtueller ILs in verschiedenen klimatischen Szenarien vorherzusagen und auszuwerten. Verwendung von 50 Tomaten-Introgressionslinien (ILs) und zwei Elternlinien: S. pennellii und S. lycopersicum cv. M82, wurde diese Studie unter Gewächshausbedingungen durchgeführt, indem ein terminaler Trockenstress im siebten Blattstadium festgestellt wurde. Es bestand ein hoher (R2= 0,67 -0,75) kausaler Zusammenhang zwischen unbelasteten und belasteten Leistungen für erhöhte Blattflächen, transpirierte Wasser und produzierte Sprosstrockenmasse. Die Änderung der Plastizität des Trockengewichts der Triebe wurde hauptsächlich durch die Blattfläche erklärt, während die Plastizität der kumulativen Transpiration hauptsächlich der spezifischen Transpiration zugeschrieben wurde. Mit der Eingabe von unbelasteten Werten und QTL-abgeleiteten Parametern aus der Reaktion auf Wassermangel von Blattausdehnung und stomatärer Leitfähigkeit wurde die betonte Transpiration aller ILs mit hoher Genauigkeit innerhalb der getesteten Sättigungsdefizit-Bereiche gut vorhergesagt. Um die Auswirkungen der klimatischen Faktoren zu untersuchen, wurden genotypspezifische Parameter (einschließlich der Parameter für die Dürrereaktion) in ein ökophysiologisches Modell integriert, das aus drei Modulen bestand, die hauptsächlich für das Blattwachstum, die Trockenmasseproduktion und die Transpiration bestimmt waren. Mit oder ohne den Input von Blattfläche und Bodenwasser wurde die Modellleistung getrennt nach agronomischen Zielmerkmalen bewertet. Das Modell in aggregierter Form sagte für die bewässerte Pflanze die Blattfläche, die Transpiration und die Sprosstrockensubstanz (Genauigkeit = 0,69 - 0,84) und den transpirierbaren Bodenwasseranteil (Genauigkeit = 0,66) gut voraus. Allerdings gab es eine Überschätzung der gestressten Leistung um 20 bis 30% (Genauigkeit = 0,55 - 0,77). Mit der Eingabe der Blattfläche wurde die Modellleistung für das gesamte transpirierte Wasser und das Bodenwasser deutlich verbessert. Ein genombasiertes ökophysiologisches Modell kann als Werkzeug zur Vorhersage gestresster agronomischer Leistungen in Tomaten-Introgressionslinien verwendet werden

Risk factors for lymphatic filariasis and mass drug administration non‑participation in Mandalay Region, Myanmar

Background Myanmar commenced a lymphatic filariasis (LF) elimination programme in 2000. Whilst the country has made considerable progress since then, a number of districts have demonstrated persistent transmission after many rounds of mass drug administration (MDA). The causes of unsuccessful MDA have been examined elsewhere; however, there remains little information on the factors that contribute in Myanmar. Methods We conducted an analysis of factors associated with persistent infection, LF-related hydrocoele and MDA participation in an area with ongoing transmission in 2015. A cross-sectional household survey was undertaken in 24 villages across four townships of Mandalay Region. Participants were screened for circulating filarial antigen (CFA) using immunochromatographic tests and, if positive, for microfilaria by night-time thick blood slide. Individuals 15 year and older were assessed for filariasis morbidity (lymphoedema and, if male, hydrocoele) by ultrasound-assisted clinical examination. A pre-coded questionnaire was used to assess risk factors for LF and for non-participation (never taking MDA). Significant variables identified in univariate analyses were included in separate step-wise multivariate logistic regressions for each outcome. Results After adjustment for covariates and survey design, being CFA positive was significantly associated with age [odds ratio (OR) 1.03, 95% CI 1.01–1.06), per year], male gender (OR 3.14, 1.27–7.76), elevation (OR 0.96, 0.94–0.99, per metre) and the density of people per household room (OR 1.59, 1.31–1.92). LF-related hydrocoele was associated with age (OR 1.06, 1.03–1.09, per year) and residing in Amarapura Township (OR 8.93, 1.37–58.32). Never taking MDA was associated with male gender [OR 6.89 (2.13–22.28)] and age, particularly in females, with a significant interaction term. Overall, compared to those aged 30–44 years, the proportion never taking MDA was higher in all age groups (OR highest in those  60 years, ranging from 3.37 to 12.82). Never taking MDA was also associated with residing in Amarapura township (OR 2.48, 1.15–5.31), moving to one’s current village from another (OR 2.62, 1.12–6.11) and ever having declined medication (OR 11.82, 4.25–32.91). Decreased likelihood of never taking MDA was associated with a higher proportion of household members being present during the last MDA round (OR 0.16, 0.03–0.74) and the number visits by the MDA programme (OR 0.69, 0.48–1.00). Conclusions These results contribute to the understanding of LF and MDA participation-related risk factors and will assist Myanmar to improve its elimination and morbidity management programmes

Epidemiology of Uveitis in a Tertiary Eye Center in Myanmar

To identify the characteristics of uveitis in a tertiary eye center in Myanmar. A retrospective study was undertaken to obtain the characteristics of uveitis in a tertiary eye center in Myanmar from September 2013 to September 2014, using a standard clinical protocol and tailored laboratory investigations

The prevalence of lymphatic filariasis infection and disease following six rounds of mass drug administration in Mandalay Region, Myanmar.

Lymphatic filariasis is widely endemic in Myanmar. Despite the establishment of an elimination program in 2000, knowledge of the remaining burden of disease relies predominantly on programmatic information. To assist the program, we conducted an independent cross-sectional household cluster survey to determine the prevalence of filariasis infection, morbidity and mass-drug administration coverage in four townships of the Mandalay Region: Amarapura, Patheingyi, Tada-U and Wundwin. The survey included 1014 individuals from 430 randomly selected households in 24 villages. Household members one year and older were assessed for antigenaemia using immunochromatographic test cards and if positive, microfilaraemia by night-time thick blood smear. Participants 15 years and older were assessed for filariasis morbidity by ultrasound-assisted clinical examination. The overall prevalence of infection was 2.63% by antigenaemia (95% confidence interval (CI) 1.71-4.04%) and 1.03% by microfilaraemia (95%CI 0.59-1.47%). The prevalence of hydrocoele in adult males was 2.78% (95%CI 1.23-6.15%) and of lymphoedema in both genders was 0% (95%CI 0-0.45%). These results indicate the persistence of filarial infection and transmission despite six rounds of annual mass drug administration and highlight the need for further rounds as well as the implementation of morbidity management programs in the country

Factors Influencing Proper Plantar Ulcer Care of Leprosy Patients: Experience from Mon-Ywa Township of Disabilities Survey Project, Myanmar

A cross-sectional study design was applied to explore types and ways of proper plantar ulcer care and factors influencing it. This study was conducted during 2008 in Mon-ywa Township because it is one of the ‘9 selected townships of the Disabilities survey project’. The study involved 19 patients affected by leprosy (PAL) with foot grade 2 disability, but without plantar ulcer at the time of study, 6 community members who had PAL in their immediate family and 6 community members who had PAL among their surroundings. They participated voluntarily in the study. The information was gathered by in-depth interview. Stigma attached to disability-related leprosy was still observed among the study respondents. They knew that ulcer could weaken their life and their surroundings. They were also aware of that one would gain benefit if one would free from ulcer. Personal outlook, a close attachment of their families and responsibility for the family, community’s reactions and the provision from the health service were the key factors to push and pull the PAL to perform plantar ulcer care. Consequently, as to regain the normal life in a society, despite a number of difficulties, PAL tried their best to look after the plantar ulcer along with the help from their families and relatives. As they were aware of the value of ulcer-free condition. for the future, they had positive view on plantar ulcer care not only for them but also for their families