Underlying a number of the biological challenges that bambara groundnut (Vigna subterranea (L.) Verdc.) faces NDASH an exemplar of underutilised crop species in general - there is a lack of: A) quantitative and comparative data on traits of farmer-defined importance; B) purified genetic lines, mixes and controlled crosses; C) knowledge of optimal field management and genotype-by-environment interactions; D) replicated and properly designed multi-locational field trials leading to locally selected cultivars. Bambara groundnut is a drought tolerant legume that has significant local importance in certain parts of sub-Saharan Africa and Southeast Asia. BamYIELD and its predecessor programmes have worked on overcoming its limitations, such as photoperiod sensitivity that restricts fruiting between a relatively small range of photoperiods (i.e., at or near 12-h day lengths), crossbred contrasting lines for mapping traits of importance, such as peduncle length, and explored the socio-economic issues surrounding crop production in Ghana, Nigeria and Indonesia. Progress has accelerated recently and near future plans include an international multi-locational field trial system that will serve as a germplasm evaluation and trait selection programme to both increase advantageous characteristics like drought tolerance and reduce bottlenecks like the food crop's long cooking time. The programme links multiple partners across Africa and Asia, including the International Institute for Tropical Institute, Nigeria, and Bogor Agricultural University, Indonesia. A component of the field trials programme will be an association genetics panel that will consist of 500 accessions from around the world to be developed by single genotype line selection for phenotyping and genotyping. In addition, nutritional/food profiling will take place on a range of genotypes in various agro-environments and value added products are being developed. The overall framework and methodological toolkit being designed by BamYIELD will be applicable to many other underutilised crops.

Improvements to leaf photosynthetic rates of crops can be achieved by targeted manipulation of individual component processes, such as the activity and properties of RuBisCO or photoprotection. This study shows that simple forward genetic screens of mutant populations can also be used to rapidly generate photosynthesis variants that are useful for breeding. Increasing leaf vein density (concentration of vascular tissue per unit leaf area) has important implications for plant hydraulic properties and assimilate transport. It was an important step to improving photosynthetic rates in the evolution of both C3 and C4 species and is a foundation or prerequisite trait for C4 engineering in crops like rice (Oryza sativa). A previous high throughput screen identified five mutant rice lines (cv. IR64) with increased vein densities and associated narrower leaf widths (Feldman et al., 2014). Here, these high vein density rice variants were analyzed for properties related to photosynthesis. Two lines were identified as having significantly reduced mesophyll to bundle sheath cell number ratios. All five lines had 20% higher light saturated photosynthetic capacity per unit leaf area, higher maximum carboxylation rates, dark respiration rates and electron transport capacities. This was associated with no significant differences in leaf thickness, stomatal conductance or CO2 compensation point between mutants and the wild-type. The enhanced photosynthetic rate in these lines may be a result of increased RuBisCO and electron transport component amount and/or activity and/or enhanced transport of photoassimilates. We conclude that high vein density (associated with altered mesophyll cell length and number) is a trait that may confer increased photosynthetic efficiency without increased transpiration.

With the growing concerns about the likely implications of climate change, the long term sustainability of conventional agricultural approaches and biodiversity loss have contributed to a growing interest in the potential of the so-called underutilised crops to address food, nutritional, and income security challenges. In support of their wider use, advocates of underutilised crops associate a number of benefits with them. These include agronomic and nutritional benefits such as drought tolerance and micro-nutrient content and the perceived socio-economic benefits of their wider use. It is widely suggested that the adoption of such crops can generate improved agricultural resilience and support nutrition, food and income security. Simultaneously, the adoption of underutilised crops is seen as a means of conserving biodiversity. However, scientific evidence concerning the use of such crops remains extremely limited. Crucially, little research has been undertaken concerning the contribution of such crops to the welfare of producers. This study investigates the socio-economic factors characterising the production of Bambara groundnut (Vigna subterrana (L.) Verdc.) in Northern Ghana and the impact of its production on farmers' welfare. Primary data was collected based on the 2013 farming season, 240 farmers were selected using a multi-stage sampling technique. A treatment effect model, comprising an adoption and a welfare model was estimated. The probability of adopting Bambara groundnut was found to be greater for: unmarried farmers; farmers in larger households; farmers with little or no formal education; and farmers who had no access to credit. The production of Bambara groundnut led to increased household welfare, as measured by the level of household per capita expenditure/consumption. Results suggest that while further research and support for Bambara groundnut production could contribute to addressing high poverty levels in the region, many of the basic assumptions underlying current advocacy of underutilised crops need rigorous empirical verification. Key words: Adoption, underutilised crops, Bambara groundnut, Northern Ghana, treatment effect model, welfare.

Molecular markers represent an important tool for marker-assisted breeding in major crop plant breeding programmes. Applying molecular genetics to underutilised and minor crop species is more challenging as the funds available to research and develop such crops are often severely limited. Bambara groundnut is an underutilised African legume crop with good drought tolerance. It is also grown at low levels in Southeast Asia. In this review we examine some of the applications of DNA markers and illustrate their value in bambara groundnut.

A high leaf vein density is both an essential feature of C4 photosynthesis and a foundation trait to C4 evolution, ensuring the optimal proportion and proximity of mesophyll and bundle sheath cells for permitting the rapid exchange of photosynthates. Two rice mutant populations, a deletion mutant library with a cv. IR64 background (12,470 lines) and a T-DNA insertion mutant library with a cv. Tainung 67 background (10,830 lines), were screened for increases in vein density. A high throughput method with handheld microscopes was developed and its accuracy was supported by more rigorous microscopy analysis. Eight lines with significantly increased leaf vein densities were identified to be used as genetic stock for the global C4 Rice Consortium. The candidate population was shown to include both shared and independent mutations and so more than one gene controlled the high vein density phenotype. The high vein density trait was found to be linked to a narrow leaf width trait but the linkage was incomplete. The more genetically robust narrow leaf width trait was proposed to be used as a reliable phenotypic marker for finding high vein density variants in rice in future screens.