Descriptors for African yam bean, Sphenostylis stenocarpa

African yam bean (Sphenostylis stenocarpa Hochst ex. A. Rich.) Harms is an underutilized tropical African tuberous legume. It belongs to the class Magnoliopsida; order Fabales; family Fabaceae; subfamily Papilionoideaea; and genus Sphenostylis. There are seven species in the genus Sphenostylis (Potter and Doyle 1994). African yam bean (AYB) is th

Evaluation of Variability in Proximate Compositions among Accessions of Sword bean (Canavalia gladiata Jacq. DC) and Jack bean (Canavalia ensiformis L. DC)

<span style="font-family: Times New Roman; font-size: small;"> </span><p style="margin: 0in 0in 10pt;" class="MsoNormal"><span style="color: #221e1f; line-height: 115%; font-size: 10pt;"><span style="font-family: Calibri;">Exploitation of available germplasms particularly in the developing countries is still limited despite the availability of rich gene pools. </span></span><span style="color: #221e1f; line-height: 115%; font-family: &quot;Garamond Premr Pro&quot;,&quot;serif&quot;; font-size: 10pt; mso-bidi-font-family: &quot;Garamond Premr Pro&quot;; mso-bidi-font-style: italic;">Canavalia </span><span style="color: #221e1f; line-height: 115%; font-size: 10pt;"><span style="font-family: Calibri;">species are underutilized legumes of wide importance for humans and livestock feed. Field and laboratory studies were carried out on evaluation of variability in proximate compositions within and between fifteen genotypes of </span></span><span style="color: #221e1f; line-height: 115%; font-family: &quot;Garamond Premr Pro&quot;,&quot;serif&quot;; font-size: 10pt; mso-bidi-font-family: &quot;Garamond Premr Pro&quot;; mso-bidi-font-style: italic;">Canivalia </span><span style="font-family: Calibri;"><span style="color: #221e1f; line-height: 115%; font-size: 10pt;">species collected from Genetic Resources Centre, International Institute of Tropical Agriculture (IITA), Ibadan. The study was a randomized complete block design replicated three thrice. Harvested mature seeds were analysed for proximate composition. The results revealed that moisture content ranged from 26.97 to 30.05, crude protein 15.45-21.85%, lipid 7.05-29.70%, ash 10.18-17.43%, sugar 0.75-1.37%, starch 7.40-0.26% and energy levels 1016.56-1825.82 kJ 100 g</span><span class="A6"><span style="line-height: 115%; font-family: &quot;Calibri&quot;,&quot;sans-serif&quot;; font-size: 5.5pt; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"><span style="color: #221e1f;">-1 </span></span></span><span style="color: #221e1f; line-height: 115%; font-size: 10pt;">DM. Significant (</span></span><span style="color: #221e1f; line-height: 115%; font-family: &quot;Garamond Premr Pro&quot;,&quot;serif&quot;; font-size: 10pt; mso-bidi-font-family: &quot;Garamond Premr Pro&quot;; mso-bidi-font-style: italic;">p</span><span style="color: #221e1f; line-height: 115%; font-size: 10pt;"><span style="font-family: Calibri;">&lt;0.05) variability was observed in sugar, lipid and energy contents among the accessions based on analysis of variance (ANOVA). The first principal component analysis (PCA) had the highest contribution of 31.4% to the total variation. Based on proximate composition, the 15 accessions clustered into six main groups. Lipid varied widely and significantly (</span></span><span style="color: #221e1f; line-height: 115%; font-family: &quot;Garamond Premr Pro&quot;,&quot;serif&quot;; font-size: 10pt; mso-bidi-font-family: &quot;Garamond Premr Pro&quot;; mso-bidi-font-style: italic;">p</span><span style="font-family: Calibri;"><span style="color: #221e1f; line-height: 115%; font-size: 10pt;">&lt;0.05) correlated to energy. Aggregation of accessions within the same species into a cluster revealed high similarity within a biological and taxonomic unit. The similarities among these 15 accessions could allow for inter specific hybridization.</span></span></p><span style="font-family: Times New Roman; font-size: small;"> </span

IMPROVEMENT OF ACCESSION DISTINCTIVENESS AS AN ADDED VALUE TO THE GLOBAL WORTH OF THE YAM (DIOSCOREA SPP) GENEBANK

Misidentification of accessions is a common problem in genebanks. Along the years, mistakes accumulate and this is particularly true when dealing with a large number of accessions requiring annual regeneration. Human errors such as mislabeling or misreading and material mix up during planting or storage are the main causes for misidentification of accessions. The international collection of yam, maintained at IITA, has accumulated ‘non true to type’ accessions along the years. In the present study, 53 morphological descriptors were used to detect uniformity of individuals within accessions of the yam gene bank collection i.e. agro morphological mismatch between individual plants of the same accession. Based on a similarity matrix, individual pairs with less than 0.90 similarity coefficients, which varies in six descriptors and more, were considered as distinct and mismatched, whereas those that had similarity coefficients greater than or equal to 0.90 were considered as clones from the same parent. Overall, 20.60% of the total 3156 accessions were found not true to type i.e., misidentified individuals. The descriptive analysis shows that morphological traits like distance between lobes, upward folding of leaf along main vein, young stem color, old stem color, leaf shape, leaf density and plant vigor are the most discriminative descriptors for individual identification within accession. Some other traits were also found species specific and they may aid in distinguishing misidentifications between species

Effect of various sugars and polyols on the tolerance to desiccation and freezing of oil palm polyembryonic cultures

Lors d'un prétraitement de 7 jours sur un milieu enrichi en saccharose, les teneurs en saccharose et en amidon dans les embryons somatiques augmentent jusqu'à 10 fois la teneur initiale. De plus, un nouveau sucre apparaît : l'arabinose. En revanche, les teneurs en glucose et fructose restent constantes au cours du prétraitement. La reprise de croissance après un prétraitement seul est satisfaisante pour tous les sucres testés, excepté en ribose. En revanche, si une déshydratation sur silica-gel est réalisée après le prétraitement, seuls le fructose, le galactose, le glucose et le saccharose permettent d'obtenir une reprise de croissance optimale. Sans déshydratation sur silica-gel, seuls les embryons prétraités avec du saccharose survivent après cryoconservation. En revanche, si une déshydratation est réalisée après le prétraitement, on obtient une survie optimale avec le fructose, le galactose, le raffinose et le saccharose. Une survie plus faible est également obtenue avec le sorbitol et le glucose. (Résumé d'auteur