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Identification of quantitative trait loci associated with bacterial spot race T4 resistance in intra-specific populations of tomato (<i>Solanum lycopersicum</i> L.<i>)</i>

by Pragya Adhikari, Muhammad Irfan Siddique, Frank J. Louws, Dilip R. Panthee

Bacterial spot of tomato is a serious disease caused by at least four species and four races of Xanthomonas- X. euvesicatoria (race T1), X. vesicatoria (race T2), X. perforans (race T3 and T4), and X. gardneri, with X. perforans race T4 being predominant in the southeast USA. Practical management of this disease is challenging because of the need for more effective chemicals and commercially resistant cultivars. Identification of genetic resistance is the first step to developing a disease-resistant variety. The objective of this study was to identify quantitative trait loci (QTL) conferring resistance to race T4 in two independent recombinant inbred lines (RILs) populations NC 10204 (intra-specific) and NC 13666 (interspecific) developed by crossing NC 30P x NC22L-1(2008) and NC 1CELBR x PI 270443, respectively. Seven QTLs on chromosomes 2, 6, 7, 11, and 12 were identified in NC 10204. The QTL on chromosome 6 explained the highest percentage of phenotypic variance (up to 21.3%), followed by the QTL on chromosome 12 (up to 8.2%). On the other hand, the QTLs on chromosomes 1, 3, 4, 6, 7, 8, 9, and 11 were detected in NC 13666. The QTLs on chromosomes 6, 7, and 11 were co-located in NC 10204 and NC 13666 populations. The donor of the resistance associated with these QTL in NC 10204 is a released breeding line with superior horticultural traits. Therefore, both the donor parent and the QTL information will be useful in tomato breeding programs as there will be minimal linkage drag associated with the bacterial spot resistance.

Understanding the dynamics of chemsex among men who have sex with men, male sex workers and transgender women in Dhaka, Bangladesh: a multiphase sequential mixed-method research protocol

Por: Sarwar · G. · Irfan · S. D. · Reza · M. · Khan · M. N. M. · Khan · S. I.
Introduction

Chemsex is defined as drug use to enhance sexual pleasure. Global literature illustrated the pervasiveness of chemsex among men who have sex with men (MSM) and transgender women (hijra) for prolonging anal intercourse, reducing pain and intensifying pleasure, oftentimes without condoms. Global literature highlighted the association between chemsex and unsafe sexual behaviours. These circumstances warrant targeted chemsex research to explore the chemsex situation. The study aims to explore the overall dynamics of chemsex among MSM, male sex workers (MSW) and hijra in Dhaka, Bangladesh and formulate culturally relevant, context-specific, gender-sensitive and evidence-based recommendations for chemsex interventions.

Methods and analysis

This will be a sequential, exploratory, mixed-methods study. Data will be collected at four drop-in centres in Dhaka in three phases. To explore issues related to chemsex, the formative phase (phase 1) will generate evidence on the overall dynamics of chemsex through a literature review and qualitative interviews. Qualitative data will be manually analysed using thematic analysis. In phase 2, a cross-sectional survey will be conducted among 458 MSM, male sex workers and hijra to measure the prevalence, reasons and sexual risk behaviour associated with chemsex. In phase 3, qualitative interviews will be conducted with the participants involved in chemsex, service providers and relevant stakeholders to add qualitative depth to survey responses. In this phase, service provision will also be investigated for people engaging in chemsex. Moreover, based on the findings of phases 1 and 2, and qualitative interviews of phase 3, a preliminary chemsex intervention model will be developed through a series of intervention design workshops.

Ethics and dissemination

Ethical approval has been attained from the Ethical Review Committee of icddr,b. Informed consent will be obtained from the participants, and confidentiality will be maintained during data collection and storage. Findings will be disseminated via several platforms including dissemination seminars, scientific articles and study report.

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