To date, several viruses of different genera have been reported to infect yam (Dioscorea spp.). The full diversity of viruses infecting yam, however, remains to be explored. High-throughput sequencing (HTS) methods are increasingly being used in the discovery of new plant viral genomes. In this study, we employed HTS on yam to determine whether any undiscovered viruses were present that would restrict the international distribution of yam germplasm. We discovered a new virus sequence present in 31 yam samples tested and have tentatively named this virus “yam virus Y” (YVY). Twenty-three of the samples in which YVY was detected showed mosaic and chlorotic leaf symptoms, but Yam mosaic virus was also detected in these samples. Complete genome sequences of two YVY viral isolates were assembled and found to contain five open reading frames (ORFs). ORF1 encodes a large replication-associated protein, ORF2, ORF3 and ORF4 constitute the putative triple gene block proteins, and ORF5 encodes a putative coat protein. Considering the species demarcation criteria of the family Betaflexiviridae, YVY should be considered as a novel virus species in the family Betaflexiviridae. Further work is needed to understand the association of this new virus with any symptoms and yield loss and its implication on virus-free seed yam production.

Plant cryopreservation is useful for long term storage of clonal germplasm and endangered species. Clonally propagated crops which produce recalcitrant seeds cannot be easily conserved using conventional methods. Preservation of plants in vitro is limited to two years and not ideal for germplasm storage for a very long time. The need to conserve plant genetic resources through cryopreservation techniques to mitigate the effects of climate change such as extinction of certain plant species cannot be underestimated. Different cryopreservation methods including dehydration, programmed freezing, vitrification and v cryo-plate are employed in the long-term storage of different plants. These methods are usually based on the principle of the removal of freezable water from tissues by physical or osmotic dehydration followed by ultra-rapid freezing. There have been several advancements in the identification and use of cryoprotective agents, nonetheless, its toxicity remains a challenge. To accelerate plant cryopreservation, there is the need for the development of global expertise. The current practice for the conservation of germplasm in the Biotechnology Laboratory in Ghana is through the use of slow growth media. Moving forward, there is the need to work on developing cryopreservation protocols for preservation of germplasm using liquid nitrogen and cryogenic refrigerators.

Ceiba pentandra (L.) Gaertn (trade name Ceiba) of the family Bombacaceae is an important multi-purpose tree species in Ghana and demand for it is rising daily. As a result, it has been included as one of the species for the National Forest Plantation Development Programme of Ghana as part of the efforts towards its restoration. Seedlings for the programme are being raised from seed collected from the wild without regard for their genetic quality and its future adverse effects. The absence of adequate information on the genetic diversity within the species therefore serves as a potential threat to its long term sustainable management and efficient genetic conversation. The phylogenetic relationships of 36 genotypes of C. pentandra from natural range of the species in five ecological zones (populations) of Ghana were therefore analyzed using 10 polymerase chain reaction (PCR) markers (5 random amplified polymorphic DNAs (RAPDs) and 5 inter simple sequence repeats (ISSRs)). The principal component analysis (PcoA) defined by axis 1 and 2 accounted for 67.15% of the variation observed. Cluster analysis using GeneStat Discovery showed that, 14 (38.89%), 21 (58.33%) and 4 (11.11%) of the accessions had a coefficient of similarity of 1 from the RAPD, ISSR and the combined RAPD and ISSR polymorphism respectively. The most distantly related accessions from the RAPD polymorphism analysis were BAW 1 and KON 8 with a similarity coefficient of 0.06 whereas those from the ISSR polymorphism were BAW 10 and ASE 1 with 21% similarity between them. Similarly, BUF 1 and KUE 1 were the most dissimilar accessions from the combined RAPD and ISSR fragments analysis with a similarity coefficient of 0.23. Nine (25%) accessions with high degree of dissimilarity between them were identified in the study. These accessions could serve as good candidates for conservation as seed trees and in breeding programs of C. pentandra in Ghana. Implications of the findings for effective management of the genetic resources of the species were also discussed.

A lot of research initiatives have gone into the breeding of cassava which has led to the development and release of over 30 cassava varieties in Ghana, of which adoption rate is 40%. This low adoption is due to inadequate promotion of improved varieties and the fact that some of the varieties do not meet end-user needs. With cassava becoming an important cash crop, it is important that breeding programmes refocus to define the market segments and objectives to facilitate the improvement of target traits such as poundability, dry matter content, starch and carotenoids that will lead to the development of varieties tailored towards end-user needs. This will in the long run promote food and nutritional security especially in low- and middle-income countries where the crop is a major staple. In addition, there should be more investment in high-throughput phenotyping to enhance the assessment and evaluation for the development of varieties with end-user traits. Subsequently, the cassava seed system should be formalized to enhance the production and dissemination of high-quality improved cassava varieties with end-user traits.