MECHANISM FOR POLLINATION IN AFRICAN YAM BEAN

African yam bean (AYB) ( Sphenostylis stenocarpa (Hochst Ex. A. Rich) Harms is a neglected and underutilised legume in tropical Africa. Its utilisation has been hampered by the presence of anti-nutritional factors and lack of improved varieties. The objective of this study was to investigate pollination and determine the rates of selfing and outcrossing in the species. Accession TSs5 had the highest fruit set (63.16%) in the open-pollinated breeding method; while AYB50 had the lowest value (46.61%). Seed set in the selfed accessions ranged from 91.45% (AYB50) to 94.97% (TSs66). Fruit set was highest in the open-pollinated breeding method, with a mean average fruit set of 51.32%. Significant differences (P < 0.01) were obtained in fruit set from accessions isolated with net bags which had the lowest seed set (88.91%) Seed set was highest (92.92%) in the selfed accessions. The self incompatibility index ranged from 1.33 to 2.26 and the rate of fruit set from artificial self-pollination was greater than 30% in the field, and the screen house showing that the species is highly self compatible. Selfing and outcrossing rates of 91.38 and 8.62% showed that S. stenocarpa is not an obligate selfer. AYB sets fruits and seeds when open pollinated, isolated, selfed or crossed with other accessions.La l\ue9gumineuse igname de l\u2019Afrique (AYB) ( Sphenostylis stenocarpa (Hochst Ex. A. Rich) Harms est une l\ue9gumineuse n\ue9glig\ue9e et sous utilis\ue9e en Afrique tropicale. Sa teneur en substances toxique et le manque de vari\ue9t\ue9s am\ue9lior\ue9es constituent un frein pour son utilisation massive. Il a \ue9t\ue9 ici question d\u2019\ue9tudier sa pollinisation et de d\ue9terminer les taux de pollinisation crois\ue9e et auto-pollinisation dans l\u2019esp\ue9ce. L\u2019accession TSs5 avait le nombre de gousses le plus \ue9lev\ue9 (63,16%) sous pollinisation ouverte, tandis que l\u2019accession AYB50 a exhib\ue9 la valeur la plus faible (46,61%). Les nombres de gousses sous auto pollinisation variaient de 91,45% (AYB50) \ue0 94,97% (TSs66). Ce nombre \ue9tait plus \ue9lev\ue9 sous pollinisation ouverte, avec une moyenne de 51,32%. Des differences significatives (P < 0.01) ont \ue9t\ue9 observ\ue9es dans les nombres de gousses chez les accessions prot\ue9g\ue9es par des filets et qui avaient les plus faibles nombres de grains (88,91%). Le nombre de grains le plus \ue9lev\ue9 (92,92%) \ue9tait observ\ue9 par auto pollinisation. L\u2019indice de d\u2019auto incompatibilit\ue9 \ue9tait de 1,33 \ue0 2,26 et le taux de fructification chez les plantes artificiellement auto pollinis\ue9es \ue9tait sup\ue9rieur \ue0 30% dans le champs, et en serre, indiquant ainsi que l\u2019esp\ue8ce est hautement auto compatible. Les taux d\u2019auto pollinisation 91,38 et de pollinisation crois\ue9e 8,62% montrent que l\u2019auto pollinisation chez S. stenocarpa n\u2019est pas obligatoire. AYB produit des gousses et graines sous toutes forms de pollinisation

Molecular characterization of Auricularia spp from south-western Nigeria using Random Amplified Polymorphic DNA (RAPD) markers

This study was conducted to investigate the genetic diversity in 48 samples of Auricularia species randomly collected from secondary forests in Osun (11), Oyo (10), Ondo (9), Ekiti (8), Ogun (8) and Lagos States (8) of Nigeria. Fourteen Random Amplified Polymorphic DNA (RAPD) markers were used for molecular characterization of Auricularia species. Phylogenetic relations were determined by cluster analysis and Polymorphic Information Content (PIC) and gene diversity determined using standard procedures. The Auricularia species were grouped into 6 distinct clusters based on morphological traits. The PIC value ranged from 0.5594 (OPH-15) to 0.7819 (OPB-12) and gene diversity from 0.5930 (OPH-15) to 0.7977 (OPB-12). Primer OPB-12 was the most informative for genetic diversity of Auricularia species. However, primer OPB-21 gave the highest number of alleles while OPB-12 showed the highest range of gene diversity and accounted for the diversity of the Auricularia species. The dendrogram and the principal coordinate analysis exhibited similar clustered patterns, revealing that all the tested strains could be divided into six distinct groups, each of which correlated with different geographical regions. Molecular characterisation is essential in genetic diversity studies and has proven useful in the classification of Auricularia spp.Keywords:  Auricularia spp, Cluster analysis, Genetic diversity, Mushroom cultivation, Principal coordinate analysis, Polymorphic information content, RAPD marker

Serological detection of seed borne viruses in cowpea regenerated germplasm using Protein A sandwich enzyme linked immunorsorbent assay

Cowpea ( Vigna unguiculata (L.) Walp) is susceptible to a number of fungal, bacterial and viral diseases. The effects of viruses can be devastating and are a major constraint to the production of cowpea. A study was carried out to detect the presence of seed borne viruses in fourteen cowpea accessions screened from 300 regenerated cowpea germplasm from the genebank collection of the International Institute of Tropical Agriculture (IITA) in Nigeria. Protein A Sandwich Enzyme linked Immunosorbent Assay (PAS ELISA) was used to detect seed borne viruses in the accessions. Out of 36 accessions of TVu 2033 indexed, 31 were infected with Cowpea aphid-borne mosaic virus genus Potyvirus, which is of great economic importance in germplasm conservation and exchange between countries as it causes great loss. Southern bean mosaic virus was not detected in any of the accessions evaluated. Seeds were harvested from the infected mother plants at maturity and the embryos excised in vitro onto hormone free medium composed of 4.43 g MS basal salt, 30 g sucrose and 8 g of agar. The seedlings obtained were serologically indexed to detect any seed-borne viruses after acclimatisation to screen house conditions. The seedlings obtained from excised embryos got from harvested seeds gave a negative ELISA result.Le niébé ( Vigna unguiculata (L.) Walp) est sensible à un certain nombre de maladies fongiques, bactériennes et virales. Les effets des virus peuvent être dévastateurs et constituent un obstacle majeur à la production de niébé. Une étude a été effectuée pour détecter la présence de virus transmis par la semence dans quatorze accessions de niébé sélectionnées parmi les 300 régénérées à partir du germoplasme collecté dans la banque de gènes de l'Institut International d'Agriculture Tropicale (IITA) au Nigeria. Un test PAS ELISA (Protein A Sandwich Enzyme linked Immunosorbent Assay) a été utilisé pour détecter les virus transmis par la semence dans les accessions. Parmi les 36 accessions testées de TVu 2033 indexées, 31 étaient infectées par le virus du genre Potyvirus (Cowpea aphid-borne mosaic virus ), virus réputé d'une grande importance économique dans la conservation du germoplasme et l'échange entre les pays eu égard aux pertes qu'il entraîne. "Southern bean mosaic virus" n'a pas été détecté dans aucune des accessions évaluées. Les semences ont été récoltées à la maturité à partir des plantes mères infectées et les embryons excisés in vitro sur un milieu sans hormone, composé de 4,43 g de sel MS, 30 g de saccharose et de 8 g d'agar. Les plantules obtenues ont subi un test sérologique afin de détecter tous les virus transmis par la semence après l'acclimatation dans la serre. Les plantules obtenues à partir d'embryons de graines excisées ont donné le résultat négatif d'ELISA

The exploitation of orphan legumes for food, income, and nutrition security in sub-Saharan Africa

Open Access Journal; Published online: 17 May 2022Poverty, food, and nutrition insecurity in sub-Saharan Africa (SSA) have become major concerns in recent times. The effects of climate change, drought, and unpredictable rainfall patterns threaten food production and sustainable agriculture. More so, insurgency, youth restiveness, and politico-economic instability amidst a burgeoning population requiring a sufficient and healthy diet remain front-burner issues in the region. Overdependence on only a few major staple crops is increasingly promoting the near extinction of many crops, especially orphan legumes, which possess immense potentials as protein and nutritional security crops. The major staple crops are declining in yield partly to their inability to adapt to the continuously changing climatic conditions. Remarkably, the orphan legumes are climate-smart crops with enormous agronomic features which foster sustainable livelihood. Research efforts on these crops have not attained a reasonable comparative status with most commercial crops. Though many research organizations and scientists have made efforts to promote the improvement and utilization of these orphan legumes, there is still more to be done. These legumes’ vast genetic resources and economic utility are grossly under-exploited, but their values and promising impacts are immeasurable. Given the United Nations sustainable development goals (SDGs) of zero hunger, improved nutrition, health, and sustainable agriculture, the need to introduce these crops into food systems in SSA and other poverty-prone regions of the world is now more compelling than ever. This review unveils inherent values in orphan legumes needing focus for exploitation viz-a-viz cultivation, commercialization, and social acceptance. More so, this article discusses some of the nutraceutical potentials of the orphan legumes, their global adaptability, and modern plant breeding strategies that could be deployed to develop superior phenotypes to enrich the landraces. Advanced omics technologies, speed breeding, as well as the application of genome editing techniques, could significantly enhance the genetic improvement of these useful but underutilized legumes. Efforts made in this regard and the challenges of these approaches were also discussed