Gliricidia sepium provides a variety of products important for rural communities in tropical countries. Native populations in Meso-America currently form an important source of seed for distribution to farmers, but concerns centre on mechanisms which may lead to their genetic erosion, including anthropogenic dispersal and subsequent introgression from the related species, G. maculata.Populations of Gliricidia were examined genetically using approaches based on the polymerase chain reaction to test for interspecific hybridization and introgression between G. sepium and G. maculata. Analysis involved 13 RAPD and two RFLP-PCR markers which were identified to have species-diagnostic distributions. Data from both approaches corresponded and indicated three locations where multilocus genotypes were consistent with an hybrid origin. Data at one of these sites was consistent with introgression following hybridization. The hybrid origin of populations was supported by the intermediate geographical location of these sites to ‘pure’ populations of each species. Analysis of maternally inherited organellar DNA, which involved the detection of SSCPs in mitochondrial DNA amplification products, allowed further delineation of genetic structure among Gliricidia populations. Mitochondrial data indicated a high degree of organelle differentiation between sampled locations and identified G. sepium- and G. maculata-diagnostic haplotypes. This data supported the interpretation of genetic structure based on RAPDs and RFLP-PCR. In addition, cytonuclear analysis allowed the directionality of gene transfer during the formation of hybrid populations to be described. Despite evidence for the occurrence of interspecific hybridization and introgression in Gliricidia, important resource populations of G. sepium on the Pacific coast appear to have retained their genetic integrity. Implications in terms of the conservation and utilization of genetic resources within the genus are discussed.
Tag: biotechnology
Agroforestry Tree Species: Acacia tortilis, Biology, Importance, Agroforestry Production, and Biotechnology Application
Indigenous tree species play a vital role in maintaining soil fertility and supporting ecosystem functioning, particularly in agricultural landscapes. Acacia tortilis, widely distributed across arid and semi‑arid regions of Africa and the Middle East, is a keystone species valued for its resilience to extreme environmental conditions such as drought, salinity, sand‑dune movement, and intensive management practices like cutting and browsing. The species provides a wide range of products—including timber, fuelwood, fodder, food, and gum—and ecosystem services such as soil health improvement, shade, cultural benefits, and medicinal uses. This chapter outlines the biology, origin, distribution, ecology, morphology, and growth management of A. tortilis, as well as its mutualistic associations with arbuscular mycorrhizal fungi and nitrogen‑fixing bacteria. It also synthesizes biotechnological research conducted on the species, highlighting its importance for sustainable land management in dryland environments.
Biodiplomacy: genetic resources and international relations
This book is about a new field of diplomacy that focusses on negotiations regarding the conservation and sustainable use of the world living resources. It is about biodiplomacy, a field that owes its origins to recent global concerns over the alarming rate at which living organisms are being lost due to human activity. This concern is emerging at a time when advances in science and technology are enhancing the economic potential that lies in the diversity of life on earth. Biodiplomacy deals with how the conservation of biological resources and their sustainable use impinge on international relations and vice versa. The world’s biological resources have been considered as the common heritage of humankind and as sovereign property of nations. The debate was resolved through protracted negotiations that resulted in the Con- vention on Biological Diversity which was adopted in 1992 and came into force in December 1993. The Convention has established a new interna- tional regime for governing the utilization and conservation of biological ie- sources. This convention delicately balances on four main pillars: conserva- tion of genetic resources, technological development, regulated access to genetic resources and international equity.
Assessing the merits of community level seedling production and distribution
One of the challenges facing projects that promote onfarmtree planting or forest plantations is how to provideseeds and seedlings at reasonable cost to planting sites.This can be overcome if planting is done on forest blocksites through the forestry department’s central nursery.Earlier attempts to promote community tree plantingbased on central nurseries operated by extension agentsor non-governmental organizations (NGOs) proved bothcostly and ineffective. To reduce costs, there are continuedefforts to decentralise seedling production anddistribution to community levels through groups or centralnurseries organized in schools, camps belonging tocommunity chiefs and privately managed nurseries.In the past, group nurseries often did not survive pastthe group formation or project support stage. Centralnurseries, also, were sometimes abandoned when fundingpriorities changed. Yet, there are success stories andmany farmers continue to be effectively reached throughsuch nurseries. Certain group nurseries, for instance,were left under the management of a single individualyet continue to supply seedlings to the community.Privately owned nurseries, in contrast, have been ableto survive for longer periods, albeit with little supportfrom developmental organizations. Depending on theoperating scenario, all three types (group, central andprivate) are feasible seedling supply alternatives and canevolve along with the awareness and tree planting cultureof the community.