This andromonoecious species has the potential for a mixed mating system with high dependence on insect-mediated pollination. The selfing rate through geitonogamy should be important.

No abstract

Taro is an important crop species in Côte d'Ivoire. It is cultivated for its tubers and leaves. But its knowledge and genetic diversity and differentiation are very weakly documented. Several morphological types are found in rural area, but their identification is not very clear, and their agronomic potentiality is underexploited. In this context we initiated a survey and collected 213 accessions from 14 growing regions of Côte d'Ivoire. The diversity was evaluated based on seven qualitative traits of leaves (Shape of the base of the leaf, Predominant position (shape) of the leaf blade surface, Margin of the leaf blade, Leaf blade variegation, Profile of the petiolar junction, Shape of the leaf sheath, Shape of the appendix) during an experimentation conducted in rural area. The objective of this study was to characterize the collection of taros collected in different geographical zones of Côte d'Ivoire and identify the genera cultivated. Results of our study indicated that excepted margin of the leaf blade all traits are very discriminant. Several variants were observed for each of traits. According to observations and statistics analysis accessions were separated into two main groups. The characteristics of these groups indicate that taro cultivated in Côte d'Ivoire could belong to two genera: Xanthosoma and Colocasia.

In Côte d'Ivoire, cassava is an important source of food and income for the population. However, its development is confronted with the attack of numerous pathogens such as phytoplasmas as observed in several countries in recent years. The main aim of this study is to diagnose cassava leaf infection in Côte d'Ivoire in order to contribute to sustainable production. Thus, cassava leaf samples were collected from nine growing localities. Molecular analyses required the use of the universal primer pairs for the direct PCR and specific primers for Nested PCR in order to detect the presence of phytoplasmas in the DNA extracted from the samples. Mosaic, vein banding, chlorosis, shoestring and witches' broom symptoms were observed, sometimes alone and other times in complex symptoms. The prevalence of leaf infections was over 70%, with average severity scores ranging from 4.29 to 4.74 depending on the cassava variety. Of the samples tested, 42 (19.44%) were positive with the specific primer (AkwaSR/GH813f) and 32 (18.39%) with the universal primer (R16mF2n/R16mR2), thus demonstrating the presence of phytoplasmas in both symptomatic and non-symptomatic cassava leaves. The amplicons obtained with the specific primer pair allowed the detection of the phytoplasma "Candidatus Phytoplasma palmicola" of subgroup XXII-B associated with the coconut lethal yellowing disease in Côte d'Ivoire in cassava grown in the different collection localities.

The aim of this study was to characterize the collection of cassava (Manihot esculenta) obtained from Côte d’Ivoire based on 14 microsatellite loci. Two hundred (200) accessions from five geographical zones – center, center-west, south, south-west, and west – were evaluated. High diversity values were found among the five above-mentioned regions, with 2.415 ± 0.153 alleles per locus on average. A high percentage of polymorphic loci varying from 38.46–100% was also observed. An average of 0.166 ± 0.026 for observed heterozygosity and 0.242 ± 0.028 for expected heterozygosity were observed too. The mean value of the Shannon index was 0.423 ± 0.048. Most genetic diversity was concentrated within the geographical zone (Hs = 0.236 ± 0.026). A high genetic differentiation among the population was found (Fst = 0.241), indicating the low level of gene flow between the population due to the infrequent sharing of cassava planting materials among farmers between regions. Based on these results, therefore, during the collecting missions, it is recommended to collect enough cassava cutting within each population to have the greatest possible diversity.