Agrobacterium-mediated transformation and regeneration of transgenic 'Chancellor' wine grape plants expressing the tfdA gene

The establishment of grape vineyards in the Midwestern USA is greatly hampered by the use of the herbicide 2,4-D in grain crop fields. The overall goal of this study was to transform 'Chancellor' with the plant expressible bacterial tfdA gene to make it tolerant to 2,4-D. Embryogenic callus was infected and cocultivated with an Agrobacterium construct (LBA4404: pAL4404::tfdA); transformed callus was selected with kanamycin; kanamycin resistant callus was bulked and transformed cell lines identified by PCR. Three PCRpositive embryogenic callus lines were used to regenerate transgenic plants. Analysis of the plant lines for the presence of the tfdA gene by PCR and southern hybridization confirmed its stable integration in their genomes. Transgenic 'Chancellor' grape plants regenerated from these calli proved to be resistant to up to 10 kg·ha-1 of a commercial ester-formulation of 2,4-D, indicating positive expression of the tfdA gene and affording them protection from 2,4-D injury

Strategies for adapting to climate change in rural Sub-Saharan Africa

Given limited resources, adaptation strategies must target those populations most vulnerable to global change and equip those unable to adapt—generally the poorest—with the tools and incentives that will enable them to do so. ASARECA has recently carried out a study to enhance the understanding of climate change in the 10 ASARECA member countries. This report profiles the available climate change–related datasets and their accessibility and procurement details in the 10 ASARECA member countries. The report additionally assesses the incorporation of climate change adaptation strategies in national development plans and discusses each country’s position in the current UNFCCC negotiations. The study was conducted using a combination of extensive literature reviews and field visits to all 10 ASARECA member countries: Burundi, Democratic Republic of Congo, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Sudan, Tanzania, and Uganda. The report is organized in four sections. The first provides a description of the available climate change–related databases, along with details about their sources and accessibility in each of the 10 ASARECA member countries. Section 3 is a review of the status of the incorporation of climate change adaptation strategies in national development plans, while section 4 discusses the countries’ positions in the current UNFCCC negotiations. Finally, section 5 offers concluding remarks and suggestions for a way forward. In addition to the study report, separate files of existing climate change–related datasets are provided in EXCEL format

Uptake of isoniazid preventive therapy and its associated factors among HIV positive patients in an urban health centre, Kenya

Background: Isoniazid Preventive Therapy (IPT) is an effective intervention for prevention of tuberculosis (TB) among HIV positive patients, and its use is recommended by the World Health Organization (WHO). Unfortunately the uptake of IPT in Kenya remains low (33%-40%) with limited knowledge on the factors that affect its uptake.Objective: To determine the uptake of IPT and its associated factors among HIV-positive patients enrolled in a urban health centre.Design: Hospital based cross-sectional studySetting: Riruta Health Centre, Nairobi, KenyaSubjects: HIV-positive patients ≥18 years who have been on care and treatment services in the health centre for at least six months preceding the study.Results: Four hundred and thirty six participants were enrolled with a mean age of 41 years (standard deviation± 9years). Females were 276 (63%), anti-retroviral therapy uptake of 427 (98%) and overall IPT uptake rate of 336 (77%). On multivariate analysis, fear of acquiring TB (adjusted odds ratio (AOR) 4.6, 95% confidence interval, CI 2.6-8.1), having received IPT-associated health education (AOR 5.0, 95% CI 3.0-8.4) and having a good relationship with the healthcare worker (HCW) (AOR 2.0, 95% CI 1.2-3.4) were independently associated with initiation of IPT.Conclusion: The uptake rate was above the current national coverage but fell below the national set target of 90%. Fear of acquiring TB, receipt of IPT-associated health education and favourable relationship with the HCWs promoted the initiation of IP

Marker assisted backcross breeding to enhance drought tolerance in Kenyan chickpea (Cicer arietinum L.) germplasm

Drought is the number one constraint in chickpea production. In the past, breeding efforts to improve terminal drought tolerance have been hindered by its quantitative genetic basis and poor understanding of the physiological basis of yield in water-limited conditions

Genomics-assisted breeding for drought tolerance in chickpea

Terminal drought is one of the major constraints in chickpea (Cicer arietinum L.), causing more than 50% production losses. With the objective of accelerating genetic understanding and crop improvement through genomics-assisted breeding, a draft genome sequence has been assembled for the CDC Frontier variety. In this context, 544.73 Mb of sequence data were assembled, capturing of 73.8% of the genome in scaffolds. In addition, large-scale genomic resources including several thousand simple sequence repeats and several million single nucleotide polymorphisms, high-density diversity array technology (15 360 clones) and Illumina GoldenGate assay genotyping platforms, high-density genetic maps and transcriptome assemblies have been developed. In parallel, by using linkage mapping approach, one genomic region harbouring quantitative trait loci for several drought tolerance traits has been identified and successfully introgressed in three leading chickpea varieties (e.g. JG 11, Chefe, KAK 2) by using a marker-assisted backcrossing approach. A multilocation evaluation of these marker-assisted backcrossing lines provided several lines with 10–24% higher yield than the respective recurrent parents.Modern breeding approaches like marker-assisted recurrent selection and genomic selection are being deployed for enhancing drought tolerance in chickpea. Some novel mapping populations such as multiparent advanced generation intercross and nested association mapping populations are also being developed for trait mapping at higher resolution, as well as for enhancing the genetic base of chickpea. Such advances in genomics and genomics-assisted breeding will accelerate precision and efficiency in breeding for stress tolerance in chickpea

Performance of marker assisted backcross breeding (MABC) elite chickpea lines under drought conditions in Kenya

Drought is the most important constraint affecting production of chickpea and other crops as well. Quantitative traits like drought tolerance are multigenic and their inheritance is difficult to predict hence the need to explore more precise breeding techniques like maker assisted selection. The aim of this study was to introgress the identified root trait QTLs into Kenyan adapted cultivar to enhance drought tolerance through marker assisted backcrossing. Four varieties Chania Desi 1 (ICCV 97105), ICCV10, ICCV 92318, and Saina K1 (ICCV 95423) were selected as a recurrent parents for improvement among ten agronomically superior elite cultivars after exhibiting high polymorphism with SSR markers. Five molecular markers (CaM1903, CaM1502, TAA 170, NCPGR21 and GA11) were validated for use in MABC deployed in this study. Crosses were made between the four parents and ICC 4958 followed by marker screening of the F1 seedling progenies for the QTL of interest. Identified true heterozygotes were used as donors and backcrossed to the recurrent parent to obtain BC1F1 seeds. The process was repeated to obtain BC2F1 and finally BC3F1 with molecular marker identification of seedlings carrying the QTL region at each step. Results of evaluation in one trial site in Kenya semi-arid area (Koibatek ATC) of MABC lines for the four parents ICCV10 (24 lines), ICCV 92318 (8lines), ICCV 97105 (12 lines) and Saina K1-ICCV 95423 (10 lines) showed that the best progenies with higher levels of drought resistance and yield were ICCMABCD-21, 9, 20, 23, 15, 22, 5, 14, 16, 19 and 6 with yields > 2.5 tons/ha. The results indicated that it is possible to transfer QTL that confers drought tolerance using MABC. The best progenies are undergoing further evaluation to validate the contribution of the introgressed QTL in improving drought tolerance and yield

Flowering margins support natural enemies between cropping seasons

Here we investigated how agricultural landscapes support natural pest regulating insects between cropping seasons; an important challenge in Pest Management by Small-Holder Farmers so aligns with this special issue. Smallholders in East Africa clear margins to provide fodder for cattle or livestock or simply to reduce the ingression of weeds into crop fields. We show that there was a significant seasonal variation in plant species richness and diversity around crops and the abundance of margin plants was strongly linked to abundance of natural enemies in the off season. The time since harvesting was also a significant factor influencing the overall abundance of natural enemies. Our paper reinforces our understanding of the importance flowering plants in agricultural systems as a refuge for natural enemies and other beneficial insects but uniquely emphasising the time between cropping seasons. Improving agricultural landscapes between crops to better support invertebrates will lead to more effective natural pest regulation early in the following crop with positive outcomes for the farmers and their families

Accountability for Practical Reasoning Agents

Postprin

Representative Agricultural Pathways and Scenarios for Regional Integrated Assessment of Climate Change Impacts, Vulnerability, and Adaptation

The global change research community has recognized that new pathway and scenario concepts are needed to implement impact and vulnerability assessment where precise prediction is not possible, and also that these scenarios need to be logically consistent across local, regional, and global scales (Moss et al., 2008, 2010). For global climate models, representative concentration pathways (RCPs) have been developed that provide a range of time-series of atmospheric greenhouse-gas concentrations into the future (Moss et al., 2008, 2010; van Vuuren et al., 2012a). For impact and vulnerability assessment, new socio-economic pathway and scenario concepts have also been developed (Kriegler, 2012; van Vuuren et al., 2012b), with leadership from the Integrated Assessment Modeling Consortium (IAMC)..

An overview of chickpea breeding programs in Kenya

Chickpea is a new crop in Kenya and its potential has not been fully utilized. The chickpea grain yields generally range between 1.2 to 3.5 tons/ha at farmers‟ fields, indicating that chickpea has a potential of becoming an important export crop in Kenya. The chickpea breeding program in Kenya is still at infant stage and being established with support from International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). Four chickpea varieties have been recently released from the breeding material supplied by ICRISAT. Efforts are being made on evaluation of germplasm and breeding lines, application of modern molecular breeding tools and techniques in chickpea breeding and establishment of effective seed system for establishing a sustainable chickpea production system in the country