Isolation of phytoplasma DNA from the coconut palms (Cocos nucifera L.) collected from Ghana

This study aimed to verify the presence of the causative agent of Lethal Yellowing which is phytoplasma in samples provided from infected coconut trees. Study was carried out by using various samples like zygotic embryo, young leaves and immature & mature inflorescences. These materials were collected from trees at the stage 1 and 2 of the disease development.. Stage 1 of disease development is characterized by leaf yellowing and the start of the falling nuts while at the stage 2 of disease development, the trees has not bear nuts longer. From infected material, DNA was extracted by three different processes and isolated DNA was amplified by PCR. 16S rRNA gene was amplified by two specific primers of phytoplama viz P1/P2 and Ghana 813/AKSR. Among the various tested materials presence of phytoplasma was reported from the mature inflorescences while the presence of the phytoplasma was not reported from the leaves and embryos of the coconut

Diversity of water yam (Dioscorea alata L.) accessions from Cote d'Ivoire based on SNP markers and agronomic traits

Open Access Journal; Published online: 24 Nov 2021Dioscorea alata (L.), also referred to as water, winged, or greater yam, is one of the most economically important staple food crops in tropical and subtropical areas. In Côte d’Ivoire, it represents, along with other yam species, the largest food crop and significantly contributes to food security. However, studies focusing on better understanding the structure and extent of genetic diversity among D. alata accessions, using molecular and phenotypic traits, are limited. This study was, therefore, conducted to assess the pattern of genetic variability in a set of 188 D. alata accessions from the National Agronomic Research Centre (CNRA) genebank using 11,722 SNP markers (generated by the Diversity Arrays Technology) and nine agronomic traits. Phylogenetic analyses using hierarchical clustering, admixture, kinship, and Discriminant analysis of principal component (DAPC) all assigned the accessions into four main clusters. Genetic diversity assessment using molecular-based SNP markers showed a high proportion of polymorphic SNPs (87.81%). The analysis of molecular variance (AMOVA) showed low molecular variability within genetic groups. In addition, the agronomic traits evaluated for two years in field conditions showed a high heritability and high variability among D. alata accessions. This study provides insights into the genetic diversity among accessions in the CNRA genebank and opens an avenue for sustainable resource management and the identification of promising parental clones for water yam breeding programs in Côte d’Ivoire

Isolation of phytoplasma DNA from the coconut palms (Cocos nucifera L.) collected from Ghana

This study aimed to verify the presence of the causative agent of Lethal Yellowing which is phytoplasma in samples provided from infected coconut trees. Study was carried out by using various samples like zygotic embryo, young leaves and immature & mature inflorescences. These materials were collected from trees at the stage 1 and 2 of the disease development.. Stage 1 of disease development is characterized by leaf yellowing and the start of the falling nuts while at the stage 2 of disease development, the trees has not bear nuts longer. From infected material, DNA was extracted by three different processes and isolated DNA was amplified by PCR. 16S rRNA gene was amplified by two specific primers of phytoplama viz P1/P2 and Ghana 813/AKSR. Among the various tested materials presence of phytoplasma was reported from the mature inflorescences while the presence of the phytoplasma was not reported from the leaves and embryos of the coconut

Effet de la p'eriode de pollinisation manuelle sur la fructification de l'igname (Dioscorea rotundata Poir; Dioscoreaceae) en Cote d'Ivoire: Effect of the manual pollination period on the fruiting of yams (Dioscorea rotundata Poir; Dioscoreaceae) in Ivory Coast

D. rotundata is the most popular species among consumers in Côte d'Ivoire. However, its production is stagnating due to the many constraints associated with its cultivation, particularly virus diseases. The use of improved varieties from sexual reproduction could effectively contribute to sustainable production. This work aimed to evaluate the crossing period in order to increase fruiting rates in this species. A total of 28 intra-specific crosses were carried out using 4 female and 7 male clones from the CNRA-Bouaké yam collection. Two time slots H1 (from 7:30 to 11:00) and H2 (from 11:00 to 13:30), selected for crossings, were compared to determine the optimal pollination period. Out of 30061 pollinated flowers, 2249 fruits were obtained i.e 7.48% with a variation range from 1.16 to 51.06% as the average fruiting rate depending on the clone combinations. Fruiting rates were significantly higher in H1 (8.53%) compared to 6.22% in H2. The female clone, Cnraigr09/00001, has recorded the highest fruiting rate especially in H1 (18.10%). Similarly, the male clones CIVCDr072, TDr00/00380 and TDr95/18555 have got the highest rates in H1 with 9.3; 9.8 and 16.3% respectively compared to those in H2. The couple Cnraigr09/00001 x TDr99/18555 recorded fruiting rates of 35.41% and 8.78% statistically different at schedule H1 and H2, respectively. A strong variation in the fruiting rate in favor of the H1 schedule was obtained between the different clone combinations. L’igname D. rotundata est l’espèce la plus appréciée des consommateurs en Côte d’Ivoire. Cependant, sa production stagne du fait des nombreuses contraintes liées à sa culture notamment les viroses. L’utilisation de variétés améliorées issues de reproduction sexuelle, pourrait contribuer efficacement à une production durable. Ce travail visait à évaluer la période des croisements afin d’accroitre les taux de fructifications chez cette espèce. Au total, 28 croisements intra-spécifiques ont été réalisés en utilisant 4 clones femelles et 7 clones mâles issus de la collection d’ignames du CNRA-Bouaké. Deux plages horaires H1 (de 7h30 à 11h) et H2 (de 11h à 13h30), retenues pour les croisements ont été comparées en vue de déterminer la période optimale de pollinisation. Sur 30061 fleurs pollinisées, 2249 fruits ont été obtenus soit 7,48% avec une variation allant de 1,16 à 51,06% de taux moyen de fructification selon les combinaisons de clones. Les taux de fructifications ont été significativement plus élevés en H1 (8,53%) contre 6,22% en H2. Le clone femelle, Cnraigr09/00001 a eu le taux de fructification le plus élevé et spécialement en H1 (18,10%). De même les clones mâles CIVCDr072, TDr00/00380 et TDr95/18555 ont eu les meilleurs taux en H1 avec respectivement 9,3 ; 9,8 et 16,3% par rapport à H2. Le couple Cnraigr09/00001 x TDr99/18555 a donné des taux de fructifications 35,41% et 8,78% statistiquement différents aux horaires H1 et H2, respectivement. Une forte variation du taux de fructification en faveur de l’horaire H1 a été obtenue entre les différentes combinaisons de clones

Assessment of water yam (Dioscorea alata L.) landrace varieties for resistance to anthracnose disease

Open Access ArticleYam anthracnose disease (YAD), caused by the fungus Colletotrichum gloeosporioides Penz, is the most damaging fungal disease of Dioscorea alata yam worldwide. Local yam varieties, which sustain Côte d'Ivoire’s farmers and other end-users livelihoods, are highly susceptible to this pathogen. Thus, there is a need for developing new yam cultivars to sustain yam production in Côte d'Ivoire. To achieve such objective, identifying and selecting sources of resistance within the existing germplasm is crucial prior to the establishment of a breeding program. This study, therefore, aimed at determining the field resistance to C. gloeosporioides of 115 D. alata landrace varieties. Field experiments were conducted at the Research Station for Food Crops (SRCV) of the CNRA, Bouaké City, in Central Côte d'Ivoire, for three growing seasons. Results showed that symptoms of the anthracnose disease were more noticeable four months after planting (P3): high disease severity and incidence scores. At this period, ‘Betebete’ group (DSS = 3.40 and DI = 99.81%) was the most sensitive to anthracnose disease across years. In contrast, ‘Brazo’ (DSS = 2.24 and DI = 94.81%) and ‘Florido’ (DSS = 2.59 and DI = 97.23%) groups were the least sensitive. This finding indicates that local yam accessions from Côte d’Ivoire have different sensitivity levels to anthracnose disease attacks. Therefore, the genetic diversity from this work should be further exploited by yam breeding and genetic improvement programs for developing cultivars, combining resistance to YAD, high yield potential, and superior tuber quality to meet producers and consumers’ needs

Estimation of genetic parameters of apple fruit quality traits using pedigreed plant material from eight european countries

The Australian Dietary Guidelines (ADGs) and Health Star Rating (HSR) front-of-pack labelling system are two national interventions to promote healthier diets. Our aim was to assess the degree of alignment between the two policies. Methods: Nutrition information was extracted for 65,660 packaged foods available in The George Institutes Australian FoodSwitch database. Products were classified core or discretionary based on the ADGs, and a HSR generated irrespective of whether currently displayed on pack. Apparent outliers were identified as those products classified core that received HSR amp;lt;= 2.0; and those classified discretionary that received HSR amp;gt;= 3.5. Nutrient cut-offs were applied to determine whether apparent outliers were high in salt, total sugar or saturated fat, and outlier status thereby attributed to a failure of the ADGs or HSR algorithm. Results: 47,116 products (23,460 core; 23,656 discretionary) were included. Median (Q1, Q3) HSRs were 4.0 (3.0 to 4.5) for core and 2.0 (1.0 to 3.0) for discretionary products. Overall alignment was good: 86.6% of products received a HSR aligned with their ADG classification. Among 6324 products identified as apparent outliers, 5246 (83.0%) were ultimately determined to be ADG failures, largely caused by challenges in defining foods as core or discretionary. In total, 1078 (17.0%) were determined to be true failures of the HSR algorithm. Conclusion: The scope of genuine misalignment between the ADGs and HSR algorithm is very small. We provide evidence-informed recommendations for strengthening both policies to more effectively guide Australians towards healthier choices.Funding Agencies|Australian Government Research Training Program (RTP) Scholarship; National Health and Medical Research Council of Australia [APP1106947]; NHMRC [APP1052555]; Centre for Research excellence [APP1117300]; County Council of Ostergotland</p