Bruce C. Pengelly

Lablab purpureus (L.) Sweet - diversity, potential use and determination of a core collection of this multi-purpose tropical legume

Two germplasm collections of Lablab purpureus L. Sweet totalling 249 accessions were grown in the field in Australia and Ethiopia and characterised using a common set of morphological and agronomic (M-A) attributes. Data from each site were analysed separately using multi-variate analysis and a classification constructed for each collection. There was considerable diversity within both collections, especially that maintained in Ethiopia. Time to flowering, seed weight, and plant height were the most important attributes in determining group allocation in both classifications. Both collections had a high proportion of L. purpureus subsp. purpureus, especially accessions similar to the Australian cultivars Highworth and Rongai. They also had good representation of the less common L. purpureus subsp. uncinatus Verdc. less common landraces and wild collections from either Africa or India. When combined, the two classifications provided an overview of diversity and highlighted the similarities and dissimilarities between the two collections. The vast range in plant types supported the view that lablab has the capacity to be a multi-purpose legume for both commercial and smallholder agriculture. Some important and less common germplasm identified were Ethiopian domesticated subsp. uncinatus, Ethiopian subsp. purpureus landraces collected from regional markets, semi-domesticated and wild accessions from southern Africa, and wild accessions from India. Using this overview, a core collection of germplasm was selected, which provides researchers with a sound basis for future plant breeding and agronomic studies with this important tropical legume.

Determining Sources of Diversity in Cultivated and Wild Lablab purpureus Related to Provenance of Germplasm by using Amplified Fragment Length Polymorphism

To improve understanding of diversity of Lablab purpureus and establish relationships among 103 germplasm accessions collected from diverse geographic origins, amplified fragment length polymorphism markers were used. Four primer sets selected out of 16 produced 289 clear, repeatable polymorphisms. UPGMA analysis of similarity data clustered the accessions according to their subspecific taxonomic organization, i.e., subsp. purpureus and subsp. uncinatus, as well as to cultivated and wild forms. The well-represented landraces from Africa and Asia, belonging predominantly to subsp. purpureus, displayed moderate genetic diversity. Wild forms from Africa showed far greater levels of diversity that would justify taxonomic re-assessment of the wild subsp. uncinatus. The molecular analysis identified forms that were collected in the wild in India but were genetically placed intermediate between wild and cultivated forms. As these plant types did not exist among the African accessions, it is suggested that they might represent escapes from early attempts of domestication. These results support the suggested pathway of domestication and distribution of L. purpureus from Africa to Asia. Additional members to a previously published core collection of the species are proposed.

Lablab purpureus—A Crop Lost for Africa?

In recent years, so-called ‘lost crops’ have been appraised in a number of reviews, among them Lablab purpureus in the context of African vegetable species. This crop cannot truly be considered ‘lost’ because worldwide more than 150 common names are applied to it. Based on a comprehensive literature review, this paper aims to put forward four theses, (i) Lablab is one of the most diverse domesticated legume species and has multiple uses. Although its largest agro-morphological diversity occurs in South Asia, its origin appears to be Africa. (ii) Crop improvement in South Asia is based on limited genetic diversity. (iii) The restricted research and development performed in Africa focuses either on improving forage or soil properties mostly through one popular cultivar, Rongai, while the available diversity of lablab in Africa might be under threat of genetic erosion. (iv) Lablab is better adapted to drought than common beans (Phaseolus vulgaris) or cowpea (Vigna unguiculata), both of which have been preferred to lablab in African agricultural production systems. Lablab might offer comparable opportunities for African agriculture in the view of global change. Its wide potential for adaptation throughout eastern and southern Africa is shown with a GIS (geographic information systems) approach.

Geographical patterns of genetic variation in two species of Stylosanthes Sw. using amplified fragment length polymorphism

Understanding the extent and distribution of genetic diversity within a species is essential for the development of effective conservation strategies. The objective of this study was to assess genetic variation using amplified fragment length polymorphisms (AFLP) in two species of the tropical legume genus Stylosanthes Sw. Annual, S. humilis (2n = 20) and perennial, S. viscosa (2n = 20) are found throughout tropical America, and are sympatric for much of their range of distribution. One hundred and eleven accessions, covering a wide geographical range, were selected for AFLP analysis. Binary data matrices derived from DNA banding patterns were analysed using the software programs ntsys‐pc and arlequin. Several accessions were found to be misidentified. Of the S. humilis accessions, the overall average similarity value was (0.72) slightly higher than the value obtained for S. viscosa (0.67). Cluster analysis and principal coordinate analysis grouped accessions from both species by geographical origin, with a few exceptions. Analysis of molecular variance (amova) in S. humilis revealed 59.4% of the variation among groups formed from the cluster analysis. This was highly significant (P < 0.001). For S. viscosaamova also revealed more variation among than within groups (66.5%). This was also highly significant (P < 0.001). The majority of accessions of both species conserved ex situ are of Brazilian and Venezuelan origin. This study has identified areas in Central America and Mexico for which novel genetic variation may be found and where conservation activities should be focused.

Genetic relationships and variation in the tropical mimosoid legume Desmanthus assessed by random amplified polymorphic DNA

A number of Desmanthus spp. are being evaluated for forage potential on clay soils in the tropics and subtropics and three cultivars have already been released in Australia. These accessions have been chosen from the large number of Desmanthus accessions collected from the Americas over the last 40 years. The utilization of this genetic resource is dependent on understanding the diversity within and between species. Hence 284 accessions, representing 11 species, were analysed using RAPD markers. There was considerable polymorphism in D. virgatus, D. leptophyllus and D. pernambucanus but this was not always uniform across the geographical range of these species. There was little polymorphism in D. pubescens. Few accessions of D. acuminatus, D. paspalaceus and D. tatuhyensis were represented in the collection, but these species, which have an almost sympatric distribution in Paraguay/Uruguay/Argentina/Brazil, showed affinities to D. leptophyllus and to each other. D. pernambucanus was the only species with representatives from regions other than the Americas, suggesting that this species in particular has the capacity to colonize new regions. The analysis indicated that the non-American D. pernambucanus germplasm probably originated from Brazil.

Programmes, projects and learning inquiries: institutional mediation of innovation in research for development

This paper explores innovation processes and institutional change within research for development (R4D). It draws on learning by Australian participants associated with the implementation of a three-year Australian-funded food security R4D programme in Africa, and in particular a sub-component designed to support and elicit this learning. The authors critically examine this attempt at institutional innovation via the creation of a ‘learning project’ (LP) in a larger programme. For systemic innovation to be achieved, it is concluded that the system of concern must envisage institutional innovation and change within the donor and external research organizations as well as with project recipients and collaborative partners. Institutional constraints and opportunities are explored, including how the overall approach to learning in this programme could have been reframed as an organizational innovation platform (IP), designing, managing and evaluating IPs at different systemic levels of governance – including within the collaborative programme with African partners, in the constituent in-country projects, in the collaborating Australian organizations and at the level of personal practice.

Farming Systems, Emerging Farmers and Land Reform in the Limpopo Province of South Africa

Limpopo Province, in the north of the Republic of South Africa, has traditionally had two agricultural sectors, commercial and subsistence, that evolved under the land and social policies of pre-democracy governments. Post-apartheid land reform has created opportunities for the previously disadvantaged population to own and farm land. These new farmers, together with subsistence farmers attempting to commercialise, now make up a middle group termed the ‘emerging farmer’ sector. However, these emerging farmers face significant barriers that include lack of secure tenure inadvertently created by government policies and inadequate delivery of government services. Other challenges result from poor knowledge about farming, lack of motivation and organisation, and previous unsustainable land management practices. Despite these barriers, new farming systems are developing which provide farmers with opportunities to share resources, and to co-operate in purchasing better quality inputs, in the development of specialised markets for livestock, and in bulking commodities and other farm produce to meet market specifications. Many of these opportunities will require outside assistance to develop new systems and build human capacity. Improving the livelihood of emerging farmers needs an integrated approach between the farmers, extension workers, research and development advisors and government policy makers. Intervention strategies must take into account the risk, resource constraints and the social and economic objectives of the individuals or groups concerned, with progress through small incremental changes. This chapter provides background on the origins of the emerging farmer sector and focuses on practical opportunities for supporting these farmers.