Participatory Variety Selection for enhanced promotion and adoption of improved finger millet varieties: A case for Singida and Iramba Districts in Central Tanzania

Participatory variety selection (PVS) is an approach which provides a wide choice of varieties to farmers to evaluate in their own environment using their own resources for increasing production. It enhances farmer’s access to diverse crop varieties, increases production and ensures food security and helps faster dissemination and adoption of pre and released varieties. It allows varietal selection in targeted areas at cost-effective and timely manner and helps promotion of community seed production and community seed banks. Therefore, a variety developed through PVS usually meets demand of different stakeholders. Farmers in Singida and Iramba districts in central Tanzania were found to be growing land races which were low yielding, long maturing, drought and disease susceptible, as no variety had previously been released in Tanzania. Through PVS a broader choice of varieties that matched farmer needs in adaptation and quality traits was offered for evaluation. As such PVS was used to introduce, evaluate, release and promote for adoption finger millet varieties in Central and Northern Tanzania. Farmers selected and adopted new varieties of a higher utility (a combination of improved agronomic traits, higher yield, and improved quality). Through PVS Tanzania released her first finger millet varieties (U15 and P224). Adoption of the varieties was very high as farmers associated with the varieties; and affordable high quality seed was made available as Quality Declared Seed (QDS) produced by the target farmer groups. Preferred traits differed between the gender groups; women preferred risk averting traits like short duration, drought tolerance, compact heads and disease resistance while male preferred market related traits (high yield, brown colour and big head

Reconstructing Asian faunal introductions to eastern Africa from multi-proxy biomolecular and archaeological datasets

Human-mediated biological exchange has had global social and ecological impacts. In subS-aharan Africa, several domestic and commensal animals were introduced from Asia in the pre-modern period; however, the timing and nature of these introductions remain contentious. One model supports introduction to the eastern African coast after the mid-first millennium CE, while another posits introduction dating back to 3000 BCE. These distinct scenarios have implications for understanding the emergence of long-distance maritime connectivity, and the ecological and economic impacts of introduced species. Resolution of this longstanding debate requires new efforts, given the lack of well-dated fauna from high-precision excavations, and ambiguous osteomorphological identifications. We analysed faunal remains from 22 eastern African sites spanning a wide geographic and chronological range, and applied biomolecular techniques to confirm identifications of two Asian taxa: domestic chicken (Gallus gallus) and black rat (Rattus rattus). Our approach included ancient DNA (aDNA) analysis aided by BLAST-based bioinformatics, Zooarchaeology by Mass Spectrometry (ZooMS) collagen fingerprinting, and direct AMS (accelerator mass spectrometry) radiocarbon dating. Our results support a late, mid-first millennium CE introduction of these species. We discuss the implications of our findings for models of biological exchange, and emphasize the applicability of our approach to tropical areas with poor bone preservation

Evidence of Yersinia pestis DNA in rodents in plague outbreak foci in Mbulu and Karatu Districts, northern Tanzania

Tanzania journal of health research, 2013, Vol. 15, Issue 3Human plague remains a public health concern in Tanzania despite its quiescence in most foci for years, considering the recurrence nature of the disease. Appreciable researches have involved serological screening of rodents, fleas and humans but none has involved molecular detection and hence proving the presence of Yersinia pestis in rodents in the most recent affected foci, Mbulu and Karatu districts in northern Tanzania. The objective of the current study was to employ a simple PCR to detect Yersinia pestis plasminogen activator (pla) gene in various potential mammalian hosts/reservoirs. The study was conducted in five villages in Mbulu and one in Karatu districts during the period of no disease outbreak. Rodents and small wild carnivores were captured, anaesthetized, identified, sexed and autopsied. Liver, spleen, heart and lung specimens were collected and DNA extracted after which PCR was used to detect the Y. pestis pla gene. A total of 517 small mammals were captured; of which, 493 (95.4%) were from Mbulu and 24 (4.6%) from Karatu. Two Mastomys natalensis (one from each district) and one Gerbilliscus sp. in Mbulu district were positive for Y. pestis pla gene. In conclusion, our results have provided a proof on the presence of Y. pestis in the two rodent species (Mastomys natalensis and Gerbilliscus sp.) and thus providing indicative evidence that the two are potential reservoirs of the pathogen and hence may be responsible for maintaining the same during periods of no disease outbreaks

Evidence of Yersinia pestis DNA in rodents in plague outbreak foci in Mbulu and Karatu Districts, northern Tanzania

Tanzania journal of health research, 2013, Vol. 15, Issue 3Human plague remains a public health concern in Tanzania despite its quiescence in most foci for years, considering the recurrence nature of the disease. Appreciable researches have involved serological screening of rodents, fleas and humans but none has involved molecular detection and hence proving the presence of Yersinia pestis in rodents in the most recent affected foci, Mbulu and Karatu districts in northern Tanzania. The objective of the current study was to employ a simple PCR to detect Yersinia pestis plasminogen activator (pla) gene in various potential mammalian hosts/reservoirs. The study was conducted in five villages in Mbulu and one in Karatu districts during the period of no disease outbreak. Rodents and small wild carnivores were captured, anaesthetized, identified, sexed and autopsied. Liver, spleen, heart and lung specimens were collected and DNA extracted after which PCR was used to detect the Y. pestis pla gene. A total of 517 small mammals were captured; of which, 493 (95.4%) were from Mbulu and 24 (4.6%) from Karatu. Two Mastomys natalensis (one from each district) and one Gerbilliscus sp. in Mbulu district were positive for Y. pestis pla gene. In conclusion, our results have provided a proof on the presence of Y. pestis in the two rodent species (Mastomys natalensis and Gerbilliscus sp.) and thus providing indicative evidence that the two are potential reservoirs of the pathogen and hence may be responsible for maintaining the same during periods of no disease outbreaks

Evidence of Yersinia pestis DNA in rodents in plague outbreak foci in Mbulu and Karatu Districts, northern Tanzania

Human plague remains a public health concern in Tanzania despite its quiescence in most foci for years, considering the recurrence nature of the disease. Appreciable researches have involved serological screening of rodents, fleas and humans but none has involved molecular detection and hence proving the presence of Yersinia pestis in rodents in the most recent affected foci, Mbulu and Karatu districts in northern Tanzania. The objective of the current study was to employ a simple PCR to detect Yersinia pestis plasminogen activator (pla) gene in various potential mammalian hosts/reservoirs. The study was conducted in five villages in Mbulu and one in Karatu districts during the period of no disease outbreak. Rodents and small wild carnivores were captured, anaesthetized, identified, sexed and autopsied. Liver, spleen, heart and lung specimens were collected and DNA extracted after which PCR was used to detect the Y. pestis pla gene. A total of 517 small mammals were captured; of which, 493 (95.4%) were from Mbulu and 24 (4.6%) from Karatu. Two Mastomys natalensis (one from each district) and one Gerbilliscus sp. in Mbulu district were positive for Y. pestis pla gene. In conclusion, our results have provided a proof on the presence of Y. pestis in the two rodent species ( Mastomys natalensis and Gerbilliscus sp.) and thus providing indicative evidence that the two are potential reservoirs of the pathogen and hence may be responsible for maintaining the same during periods of no disease outbreaks

Detection of Yersinia pestis DNA in human bubo aspirates in Tanzania

The use of molecular techniques to detect Yersinia pestis has enabled remarkable progress in the provision of necessary information on the occurrence of plague. In Tanzania, despite the long history of plague, DNA confirmation on the presence of Y. pestis in human specimens has not been done. This study was conducted in Mbulu district in Northern Tanzania where plague outbreaks have recently been reported. Nine human bubo specimens were investigated for Y. pestis plasminogen activator gene by using polymerase chain reaction (PCR), and two were found to be positive. The two positive amplicons, together with three previously obtained PCR positive rodent samples, were sequenced using a 3130 genetic analyzer and then compared with those available in GenBank by basic local alignment search tool (BLAST). All sequences obtained from both human and rodent samples showed 99% sequence similarity to Y. pestis plasmid pPCP1, detected from ancient DNA, confirming the presence of Y. pestis in humans that possibly sourced from rodents in Tanzania

Detection of Yersinia pestis DNA in human bubo aspirates in Tanzania

The use of molecular techniques to detect Yersinia pestis has enabled remarkable progress in the provision of necessary information on the occurrence of plague. In Tanzania, despite the long history of plague, DNA confirmation on the presence of Y. pestis in human specimens has not been done. This study was conducted in Mbulu district in Northern Tanzania where plague outbreaks have recently been reported. Nine human bubo specimens were investigated for Y. pestis plasminogen activator gene by using polymerase chain reaction (PCR), and two were found to be positive. The two positive amplicons, together with three previously obtained PCR positive rodent samples, were sequenced using a 3130 genetic analyzer and then compared with those available in GenBank by basic local alignment search tool (BLAST). All sequences obtained from both human and rodent samples showed 99% sequence similarity to Y. pestis plasmid pPCP1, detected from ancient DNA, confirming the presence of Y. pestis in humans that possibly sourced from rodents in Tanzania

Plague in Tanzania: an overview

Human plague remains a public health concern in Tanzania despite its quiescence in most foci for years, considering the recurrence nature of the disease. Despite the long-standing history of this problem, there have not been recent reviews of the current knowledge on plague in Tanzania. This work aimed at providing a current overview of plague in Tanzania in terms of its introduction, potential reservoirs, possible causes of plague persistence and repeated outbreaks in the country. Plague is believed to have been introduced to Tanzania from the Middle East through Uganda with the first authentication in 1886. Xenopsylla brasiliensis , X. cheopis , Dinopsyllus lypusus , and Pulex irritans are among potential vectors while Lophuromys spp, Praomys delectorum , Graphiurus murinus , Lemniscomys striatus , Mastomys natalensis , and Rattus rattus may be the potential reservoirs. Plague persistence and repeated outbreaks in Tanzania are likely to be attributable to a complexity of factors including cultural, socio-economical, environmental and biological. Minimizing or preventing people’s proximity to rodents is probably the most effective means of preventing plague outbreaks in humans in the future. In conclusion, much has been done on plague diagnosis in Tanzania. However, in order to achieve new insights into the features of plague epidemiology in the country, and to reorganize an effective control strategy, we recommend broader studies that will include the ecology of the pathogen, vectors and potential hosts, identifying the reservoirs, dynamics of infection and landscape ecology