Christian Siadjeu

Doktorand der AG Biodiversität und Evolution der Pflanzen 

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:

  1. assess the genetic diversity and population structure of D. dumetorum in Cameroon using morphological and molecular markers and ploidy level
  2. identify genes which are expressed among D. dumetorum accessions during storage through RNA-seq
  3. 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.


  • 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.
  • 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.
  • 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.


  • 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).

Curriculum vitae

2006 - 2009 B.Sc., Biology, University of Yaoundé 1, Cameroon
2009 - 2012 M.Sc., Plant Biotechnology, University of Yaoundé 1, Cameroon
Since October 2017 PhD student University of Oldenburg
Webs/2e5master ( (Changed: 2020-03-24)