Rice and Remittances: Crop Intensification Versus Labour Migration in Southern Laos

Despite being a low-income, agriculture-based country with a subsistence orientation, Laos is in the early stages of a major economic transformation whereby rural households have been experiencing rapid change in their farming and livelihood systems. Some households have begun to engage in semi-commercial farming while others have adopted labour-oriented or migration-oriented livelihood strategies. This paper explores how rural households in six villages in the lowlands of Champasak Province in southern Laos make a living. These villages vary in their access to irrigation and to markets. Nevertheless, in all villages, long-term migration of younger household members to neighbouring Thailand has come to play a large role in household livelihood strategies. In some cases this is necessary to meet the household’s consumption requirements; in most, it is part of a diversified strategy in which rice farming still plays a significant role, though still largely for subsistence. The paper examines some of the issues involved in attempting to promote intensive, market-oriented rice farming in a context of an emerging on-farm labour shortage combined with an increasing flow of remittances from migrant family members.     

Monophyly of Opisthorchis viverrini populations in the lower Mekong Basin,using mitochondrial DNA nad1 gene as the marker

The liver fluke, Opisthorchis viverrini, causes serious public-health problems in the Lower Mekong Basin. This study aimed to clarify whether O. viverrini populations may be genetically divided into sub-specific taxa. We collected 6 populations of O. viverrini from different places in Cambodia, Lao PDR, and Thailand, along both sides of the Mekong River, and analyzed the population structure of these using the mitochondrial nad1 gene as a marker. The results of the DNA polymorphism measurements, by theta-w (θw) and -π (θπ) values, neutrality tests, and mismatch distribution, suggested that the population of O. viverrini has expanded under the influence of purifying selection and selective sweep. The analysis of molecular variance (AMOVA) test revealed no significant genetic differences among the O. viverrini populations on opposite sides of the Mekong River. O. viverrini haplotypes occurred in multiple populations, and no distinct geographical clade. The star-like haplotype network confirmed a demographic expansion of the O. viverrini population. Overall, the genetic data from these populations suggested that the postulated existence of an O. viverrini species complex should be rejected. The bio-geographical diversity of O. viverrini populations should be explored further, using other appropriate markers and a wider range of samples from geographically different areas.