Stig Uggerhøj Andersen with the model plant Lotus japonicus, which has been developed by scientists from the Department of Molecular Biology, Aarhus University, for studying  nitrogen-fixation in plants.   Photo: Lisbeth Heilesen.             Click photo for enlargement.

Stig Uggerhøj Andersen from the Department of Molecular Biology, Aarhus University, has been awarded a DKK 5.6 million grant for three years from The Danish Council for Independent Research | Technology and Production Sciences to carry out research on the implementation of new sequencing technology in plant breeding.

2011.01.04 | Lisbeth Heilesen

Figure 1: Deep sequencing and SHOREmap QTL analysis. (A) An F2 population is generated and scored for the quantitative trait “days to flowering”. The population is subdivided based on phenotype, and individuals at the extremes of the phenotypic distribution, Pop1 and Pop3, are pooled and sequenced. The flowering time of the two mapping parents A and B are indicated. (B) Deep sequencing of the two extreme pools Pop1 and Pop3 followed by SHOREmap analysis reveals the genome-wide allele-frequency distribution. Genomic loci where Parent A alleles are enriched in Pop1 and Parent B alleles  are enriched in Pop3 (- - -) are prime candidates for influencing the quantitative trait.                                       Click figure for enlargement.

Plants provide food and feed for humans and animals. To feed a growing world population, plant performance has to be continuously improved through breeding, where plants with ever better characteristics are selected generation by generation. Some plants, including the crop plant white clover, can fix atmospheric nitrogen in symbiosis with bacteria. This enables these plants to generate high yields and supply the soil with nitrogen, independent of artificial nitrogen fertilisers. A more widespread use of such natural fertilisation could contribute to more sustainable agricultural production methods.

Scientists at Aarhus University have developed Lotus japonicus as a model plant for the study of nitrogen fixation. The research grant now offers an international consortium headed by Stig Uggerhøj Andersen the opportunity to exploit this model plant in combination with a new and very efficient sequencing technology to identify genes that control agriculturally important traits in nitrogen-fixing plants.

Further, the consortium will sequence the genome of the crop plant white clover to allow efficient translation of knowledge from model system to agricultural use. Clover is grown in large pastures around the world. In addition to the scientists at Aarhus University, the consortium consists of Danish clover breeders from DLF-Trifolium, Irish clover scientists from Teagasc and Japanese experts in genome sequencing from the Kazusa DNA Research Institute.

Identification of key genetic components

Traits that are not inherited in a predictable manner between generations are difficult to improve through traditional breeding. This is a key challenge that will be addressed in the research project. The complications often arise because a trait depends on several genetic components that each contribute to the phenotypic trait. These genetic components are called Quantitative Trait Loci (QTL), and one of the main goals in applied genetics is to identify QTL to allow breeding for traits where conventional breeding is failing. However,  QTL identification is challenging because it requires the collection and handling of very large amounts of data. So far, this has resulted in relatively few QTL being described precisely enough to be useful in breeding programmes.

Newly developed software for fast identification

Stig Uggerhøj Andersen has recently headed the development of a novel method for genetic mapping, which involves using new sequencing technology to quickly generate the large amounts of data required and then analysing it using the programme SHOREmap. The method was first used to identify a single genetic change that on its own was sufficient to alter a phenotypic trait, but the method has the potential to solve the major technical problems associated with QTL identification. Thanks to the grant, the consortium is now able to investigate the applicability of the SHOREmap method for QTL identification by examining yield traits in a model plant followed by translation of the model plant QTL results to white clover breeding programmes.

More information

Postdoctoral Fellow Stig Uggerhøj Andersen
Molekylærbiologisk Institut, Aarhus Universitet
sua@mb.au.dk, +45 8942 5013, +45 2074 7136