Analysis of genetic diversity in accessions of Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill

Amplified fragment length polymorphism (AFLP) was used to assess genetic diversity and relationships among 15 accessions of Irvingia gabonensis collected from Cameroun, Gabon, and Nigeria. Twelve AFLP+3 primers produced 384 polymorphic fragments. Average genetic distance (AGD) between the 15 accessions was 58.7% (32-88%). AGD and range of genetic distance among accessions from Cameroun, Nigeria and Gabon were 62% (53-76%), 52% (32.3 – 84.8%) and 50% (45- 53%), respectively, indicating more genetic diversity in Cameroun than Nigeria and Gabon. The unweighted pair-group method of the arithmetic average (UPGMA) and principal coordinate analysis (PCO) showed a clear distinction between the Gabon and Nigeria accessions into two separate clusters, with accessions from Cameroun overlapping them. Principal coordinate analysis (PCO) indicated a closer relationship between accessions from Cameroun and Gabon. In general the Cameroun germplasm appears to be a bridge between the genetically isolated Nigeria and Gabon accessions. This overlap of Gabon and Nigerian accessions by the accessions from Cameroun may be an indication that Cameroun is the center of diversity of I. gabonensis and also the primary source of original materials grown in the other countries. More collection in Cameroun is necessary to ensure the optimum collection and preservation of the existing genetic diversity in I. gabonensis.Keywords: Irvingia gabonensis, Accession, amplified fragment length polymorphism, genetic diversit

Flooding effects on yield of an indigenous vegetable (Amaranthus cruentus L. in the Niger Delta region of Nigeria

No abstractKeywords: Amaranthus cruentus; flooding; leaf area; vegetables; yieldGlobal Journal of Agricultural Sciences Vol. 4(1) 2005: 41-4

Rural Households\' Involvement In Social Forestry Practices In Imo State, Nigeria

Social forestry practice is an emerging concept in which rural people engage in tree farming for their own benefit. Rural households in Nigeria have not been able to embrace social forestry because the potentials of planted forests and agro-forestry to alleviate socio-environmental problems are not well understood. The involvement of rural household in social forestry practices in Imo State, Nigeria was evaluated. A structured questionnaire was administered on 80 randomly selected respondents to elicit information on social forestry practices. Data obtained were analysed using descriptive statistics. Results revealed a low level of involvement in social forestry practices. The involvement in social forestry practice is hampered by problems related to land acquisition, lack of funds, information flow, ignorance of importance of social forestry to the rural community. Suggestions were made to address fundamental strategies that can improve the introduction, adoption and operation of social forestry in the study area. Keywords: Rural households, social forestry practices, involvementGlobal Approaches to Extension Practice Vol. 3 (2) 2007: pp. 98-10

Vegetative propagation of indigenous fruit trees: influence of defoliation on survival of rooted marcots (air-layered plants) of Irvingia gabonensis and Dacryodes edulis in Onne, Niger Delta Region of Nigeria

High mortality is one of the problems limiting production of vegetative planting materials in the nursery. Vegetative propagation by air layering (marcotting) of 12 years old Irvingia gabonensis and Dacryodes edulis was carried out at International Institute of Tropical Agriculture (IITA) station in Onne from 1996 to 1997. The objective of this study was to determine the influence of defoliation on survival of rooted marcots of Irvingia gabonensis and Dacryodes edulis. Experiments were conducted with 48 rooted marcots of I. gabonensis and D. edulis. The marcots were set and harvested from mother trees of both species established in an arboretum in 1985. Treatments involved complete removal of all leaves (complete defoliation), removal of half of leaves (partial defoliation) and non-removal of leaves (retention of all leaves in the control treatment). Results indicated that partial defoliation was the most successful treatment with 100 and 66.6% survival percentages for I. gabonensis and D. edulis respectively. Retention of all leaves significantly (

Characterization of tree-to-tree variation in morphological, nutritional and medicinal properties of Canarium indicum nuts

As part of a feasibility study of the commercialization potential of C. indicum nuts as Agroforestry Tree Products in Papua New Guinea, preliminary characterization studies have examined the tree-to-tree variation in morphological traits (nut and kernel mass and kernel:nut ratio), as well as nutritional (carbohydrate, fat, protein, sodium, vitamin E) and medicinal traits (anti-oxidant activity, anti-inflammatory activity and phenolic content) of kernels from 18 to 72 trees in a small number of different villages of Papua New Guinea (East New Britain Province). There was continuous variation in these traits indicating opportunities for multiple trait cultivar development targeted at food and pharmaceutical markets. Certain traits, for example anti-inflammatory activity, in which tree-to-tree variation was highly significant, present greater opportunities than others, such as saturated:unsaturated fatty acid ratio. This intraspecific variation was greater within populations than between populations. The data presented has allowed the development of a strategy to domesticate C. indicum for cultivation in homegardens and cocoa-coconut agroforests, using a participatory approach aimed at the production of agroforestry tree products (AFTPs) to empower small-holders and enhance their livelihoods and income