KEY ACTIVITIES AND ACHIEVEMENTS
Molecular Characterization of Cocoyam (Xanthosoma Saggittifolium) and cassava – Dr Ruth Prempeh/ Henry Doku
- Genotyping of all released crop varieties in Ghana – Drs Ruth prempeh / M.D. Quain
- In Vitro Manipulation and Field Performance of Clean and Healthy Improved Root and Tuber Crops – Mr David Appiah Kubi /Albert Aurbyn
Molecular Characterization of Cocoyam (Xanthosoma Saggittifolium)
Cocoyam is less exploited scientifically especially at the molecular and cytogenetic level. The development of molecular marker systems will facilitates marker-assisted breeding, genetic diversity studies, and creation of polymorphism that allow a range of analyses from chromosome mapping through to population or clone level. In exploring the genome of cocoyam, there is the need to create an efficient marker system for evaluating its genetic relationship and also for its improvement.
Key Activities Planned
- Carry out molecular characterisation of cocoyam (Xanthosoma species).
- Develop the Diversity Array Technology (DArT) genomic profiling for ariods.
Key Result: Outputs/Outcome
- So far 20 polymorphic SSR markers developed for genetic studies with support from the Genetic Marker Services, UK.
- Forty–two (42) accessions of cocoyam collected from the CSIR-Plant genetic Resources Research Institute are yet to be characterised by the SSR markers received.
- Genomic DNAs has been extracted and these have been added to the 1,208 cocoyam accessions available at the DNA Bank. Ninety germplasm have been collected from the Volta Region and Bunso for the DArT genomic profiling.
Genotyping of released crop varieties in Ghana
Genotyping can also be referred to as fingerprinting which is the process of determining the genetic constitution – the genotype – of an individual by examining their DNA sequence. This provides information necessary to characterise germplasm, information vital to document the identity of crop varieties released. Current methods of genotyping include morphological, agronomic, and biochemical systems. Characterization based on morphologic characteristics alone may be limited since the expression of quantitative traits is subjective to strong environmental influence. Alternatively, molecular characterization techniques are capable of identifying polymorphism represented by differences in DNA sequences. This has the ability of analyzing variation at the DNA level during any stage of the development of the plant, where environmental influences are excluded. In genotyping molecular tools would be used to characterise and document fingerprint of crop varieties.
In vitro manipulation and field performance of clean and healthy improved root and tuber crops
Productivity of root and tuber crops is limited by a number of both biotic and abiotic constrains. Biotechnological interventions such as tissue culture using combinations of thermotherapy and in vitro meristem shoot tip culture techniques offer great potential for improving productivity of root and tuber crops through virus elimination and regeneration of plantlets from tissues where viruses have been excluded. Currently, information on field performance of tissue culture materials is limiting. Evaluation of conventional and tissue culture materials will establish economic benefits of using tissue culture produced "clean" planting materials. To develop a standardized protocol for the production of root and tuber crops; the study initiated and established released varieties of four root and tuber crops namely yam, sweetpotato, cocoyam and cassava in vitro. It rapidly multiplied, acclimatized and produced clean planting materials for field establishment. Field performance of these root and tuber crops will be evaluated.
- Sweetpotato: Six (6) released varieties of sweetpotato namely: Otoo, Sauti, Okumkom, Faara, Ogyefo and Santom Pona had been virus tested the second time (confirmatory test) using NCM-ELISA and certified as cleaned and healthy. These are being multiplied in-vitro and under screen-house conditions for field establishment. In collaboration with CIP-SASHA sweetpotato varieties: Mother’s Delight and King J received from Dr. Jude Njoku of NRCRI, Nigeria, and from Dr. Some Koussao of INERA, Burkina Faso have been cleaned and virus indexed by the CSIR-CRI Tissue Culture Laboratory. These materials have been delivered to their respective Clients.
- Cocoyam: A total of 475 cocoyam seedlings made up of 173 - Gye me di, 164 of Ma ye yie and 138 of Akyedie were acclimatized under screen-house conditions. These planting materials have been established in the field for evaluation. Currently 325 tissue culture materials being maintained are made up of 91 - Akyedie; 65 - Gye me di and 169 - Ma ye yie.
- Yam: A total of healthy 500 mini tubers of Mankrong Pona (a released yam variety) derived from tissue culture as seed yams were supplied to the breeder for evaluation in the field. The ultimate aim of these collaborations is to enhance multiplication and dissemination of released yam varieties to farmers.
- Taro: Total summary of TC materials in vitro are as follows: cocoyam – 1233, yam – 4269, cassava – 807 (Otuhia – 212, sika bankye – 79, Broni bankye – 477 and Ampong – 39).