Principal Supervisor: Dr Lindsey Jane Leach, School of Biosciences
Co-supervisor: Dr Eugenio Sanchez-Moran, School of Biosciences
PhD project title: Molecular Cytogenetic Analysis of Meiotic Recombination in Potato
University of Registration: University of Birmingham
Cultivated potatoes (Solanum tuberosum) have become the 3rd most important crop in the world after rice and wheat and therefore play an important role in addressing world food security. Traditional potato breeding has focused on phenotypic rather than genotypic selection to improve complex agronomic traits such as yield and disease resistance. Development of new cultivars with improved characteristics is a lengthy process that usually spans 10-15 years, and often involves species introgression to broaden the genetic base and ploidy manipulations to overcome crossability barriers between species. To improve the efficiency of potato breeding will require the development of improved strategies for genetic marker assisted selection and for shuffling the genome through meiotic recombination, thus creating new variation. To this end, this project will focus on the cytogenetic analysis of meiosis in cultivated potatoes.
Cultivated potato is an autotetraploid species with a basic chromosome number of 12 (2n=4x=48), making cytogenetic research a historical challenge. The four copies of each chromosome show tetrasomic inheritance: pairing, recombining and segregating randomly, but also show a low frequency of multivalent formation. This project will pioneer in establishing a high resolution atlas and time course of the stages of meiosis in potato and build upon existing methods using fluorescence in situ hybridisation (FISH) to enable individual meiotic chromosomes to be reliably distinguished and tracked. This will enable an in depth study of the behaviour of meiotic chromosomes in modern potato cultivars, including their pairing behaviour, frequency and distribution of meiotic recombination. Using methods we have developed for immunolocalisation of key meiotic proteins, including axis proteins ASY1 and ZYP1, the project will study the mechanisms through which the potato chromosomes pair and recombine. There will also be an opportunity to explore the effects of the commonly used ploidy manipulations in potato breeding on meiotic recombination. The results of this project will inform future potato breeding strategies and hence contribute to world food security.
- Dong F et al. (2000) Theor Appl Genet 101: 1001-1007.
- Barrell P et al. (2013) Plant Biotech J 11: 907-920.
BBSRC Strategic Research Priority: Food Security
Techniques that will be undertaken during the project:
- Experimental: Potato cultivation, potato crosses, complex trait phenotyping, PCR, RT-PCR, fluorescence microscopy, FISH, immunocytology.
- Computational: creating mathematical/statistical models for genetic studies (e.g. using Mathematica), writing programmes and scripts to analyse genetic datasets (e.g. using Fortran, C++, Perl), statistical techniques for data analysis (e.g. using statistical software R) on windows or linux systems.
Contact: Dr Lindsey Jane Leach, School of Biosciences