Christian Siadjeu
PhD thesis
Molecular breeding bases of trifoliate yam (Dioscorea dumetorum (Kunth) Pax) against post-harvest hardening phenomenon of tubers 
Yams are a staple food for millions of people in the tropics. Dioscorea dumetorum has the highest nutrient value among other yam species commonly grown and consumed. Additionally, it contains a novel bio-active compound dioscoretine, used advantageously as a hypoglycemic agent in anti-diabetic medications. Despite of these properties, the storage ability of this yam is restricted by severe post-harvest hardening of the tubers, which starts within 24 h after harvest and renders them inedible.
The main objective of the PhD project is to investigate the genetic basis of this post-harvest hardening phenomenon in D. dumetorum. Specifically, we will:
- assess the genetic diversity and population structure of D. dumetorum in Cameroon using morphological and molecular markers and ploidy level
- identify genes which are expressed among D. dumetorum accessions during storage through RNA-seq
- initiate association mapping of candidate genes involved in the post-harvest hardening phenomenon of tuber populations of D. dumetorum. At the end of this study, we expect to provide the basis for targeted molecular breeding of post-harvest hardening avoidance.
Publications
- Siadjeu, C.; Pucker, B.; Viehöver, P.; Albach, D.C.; Weisshaar, B. High Contiguity de novo Genome Sequence Assembly of Trifoliate Yam (Dioscorea dumetorum) Using Long Read Sequencing. Genes 2020, 11, 274. doi.org/10.3390/genes11030274
- Siadjeu C, Mayland-Quellhorst E, and Albach DC. (2018). Genetic diversity and population structure of trifoliate yam (Dioscorea dumetorum Kunth) in Cameroon revealed by genotyping-by-sequencing (GBS). BMC Plant Biology, (2018) 18:359. doi.org/10.1186/s12870-018-1593-x
- Siadjeu C., MahbouSomoToukam G., Bell J. M., & Nkwate S. (2015): Genetic diversity of sweet yam “Dioscorea dumetorum “(Kunth) Pax revealed by morphological traits in two agro-ecological zones of Cameroon. African Journal of Biotechnology, 14(9): 781-793.
- Toukam G. M. S., Siadjeu C., Bell J. M., Nkwate S., Bomda J. (2015): Influence de quelques caractères agronomiques sur le rendement de l’igname sucrée (Dioscorea dumetorum Kunth Pax) au Cameroun. Int. J. Biol. Chem. Sci. 9(1): 141-154.
- Siadjeu C., Panyoo A. E., Mahbou S. T. G., Bell J. M., Nono B., and Gabriel Medoua N. G. (2016): Influence of Cultivar on the Postharvest Hardening of Trifoliate Yam (Dioscorea dumetorum) Tubers. Advances in Agriculture, Volume 2016, Article ID 2658983, 7 pages, 2016. doi:10.1155/2016/2658983.
Conferences
- 18th Triennial Symposium of International Society for Tropical Roots Crops ISTRC, 2018: Poster presentation (Genetic diversity and population structure of trifoliate yam (Dioscorea dumetorum Kunth) in Cameroon revealed by genotyping-by-sequencing (GBS), Cali Colombia.
- 22th Annual Conference of the Cameroon Bioscience Society, 2015: Poster presentation (Content of Neutral lipids and fatty acid composition of the oil palm seeds Elaeis guineensis Jacq. during germination).