Monday, 23 June 2014

May Meeting

Charlie Laughton (School of Pharmacy) presented at our May meeting. He discussed Molecular Dynamics simulations, with the title:

`How long is a piece of string?'

April Meeting

Kim Kenobi presented at our April group meeting.

Wheat roots - shape and nutrient uptake efficiency

Kim Kenobi

As part of the ERC FutureRoots project, a large CT scanning facility, the Hounsfield Facility, has been built on the Sutton Bonington campus to look at root system architecture of wheat plants in the context of nitrogen and water uptake efficiency.  The 3D CT scans will be starting to become available in the next month or so.  In this talk, I will present a statistical analysis of a preliminary 2D wheat root data set.  The wheat plants in the data set come from 9 lines, all of which have been assessed for nitrogen uptake efficiency in independent field trials.  The wheat plants have been grown under low and high nitrate conditions and the roots have been imaged.  A piece of software called RootNav has been used to extract various quantitative measurements from the root systems, including total length of root, area of convex hull, maximum width and depth, and numbers of primary and lateral roots.  In addition to these traits the software returns the coordinates of points on spline curves fitted to both the primary and lateral roots.  I have used the information from these spline curves to define a distance measure between two roots and used multidimensional scaling to obtain shape variables.  In the talk I show how linear discriminant analysis reveals that there are substantive differences in the root system architecture of low and high nitrogen uptake efficiency wheat plants, and less emphatically between the different nitrate growth conditions.  Also, the shape variables derived from the spline coordinates emerge as playing an important role in discriminating between the groups.  This evidence is encouraging in the light of the aims of the FutureRoots project to identify 3D root system architectural traits that correspond to improved nutrient uptake efficiency.

March Meeting

Karthik Bharath (Ohio State University) gave a talk on `Inference for large trees' on March 26, 2014.

[OSU Statistics]