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Screening the Brassica napus DFS population for nutrient acquisition traits - IF0190

Description
There are compelling economic and environmental reasons to improve the efficiency with which crops capture and use water and nutrients in the soil. As pressure increases on global food prices and supply, a balance is needed between food production and the maintenance of healthy and diverse of ecosystems. High water abstraction and diffuse pollution from fertilisers can have negative impacts on adjacent ecosystems. Nitrogen (N) and phosphorus (P) inputs are a major source of carbon dioxide emissions and leaching of nitrogen and phosphorus from soils results in poor water quality. Breeding crops that require less fertiliser can form part of an effective mitigation strategy for reducing diffuse agricultural pollution and reducing emissions of greenhouse gases from agriculture. Following recent steep increases in the price of nitrogen and phosphorus fertilisers, and the non-renewable nature of phosphorus, there are good economic incentives for reducing fertiliser use in crop production.

Plant roots acquire the minerals plants need from the soil solution. Since the availability of most mineral elements in natural soils is poor, plants have evolved mechanisms to improve the solubility and uptake of these mineral elements through their root systems. However, crop plants are less reliant on them today, since most of the mineral elements they require are supplied in the form of easily available fertilisers. When these fertilisers are applied, the elements are incorporated into the soil. However, most soils are very good at holding on to P. Therefore, breeding crops with traits that improve the acquisition and use of applied P could result in the use of less P fertiliser and reduce our financial and environmental costs.

Since P does not move quickly through the soil. Plant roots can rapidly exhaust all the available P in their immediate vicinity. So to ensure P remains available to the plant, plants increase root growth, which increases the volume of the soil explored. In the soil, most P tends to be found in the upper layers of the soil, so rather than increasing the root growth downwards, plants that need more P, tend to increase their root growth outwards into the top layers of the soil. They generally do this by increasing the number and density of secondary roots (the roots that grow out from the primary- or tap-root). Plants can also change the angle at which these secondary roots grow. When P is in plentiful supply the secondary roots often grown downwards, but when little P is available, these roots grow almost horizontally into the top layers of the soil, to find more P.

We are currently using forward genetics to identify and map major genetic loci contributing to nutrient acquisition and use efficiency in the Brassica A and C genomes (Defra HH3501, WQ0119; BBSRC BB/G014159/1). We have generated information that will be used to breed field crops that can capture and use nutrients more efficiently. In Brassica oleracea, we have also screened extreme phenotypes for difference in their root length and lateral root growth and angle. This has confirmed that these traits are integral for the efficient capture and use of P. In order to establish the diversity of these root architectural traits in Brassica napus we will screen the B. napus diversity foundation set (BnaDFS). This will provide data on the root growth and lateral root number, growth rate and angle of these accessions and will complement existing trait evaluation work for these lines in WQ0119. This work will also be complementary to work within OREGIN and the wider Brassica community.

These projects deliver directly to Defra’s policy objectives on water quality.
Objective
7. (b) Objectives


Aim

The aim of this project is to determine the diversity of root architectural traits within Brassica napus that impact on phosphorus acquisition.

Objectives

1) To score 150 lines from the B. napus diversity foundation set (BnaDFS) for root length and growth rate, and lateral root number, length, angle and growth rate.

Project Documents
• ROAME Document : IF01   (165k)
Time-Scale and Cost
From: 2009

To: 2009

Cost: £30,272
Contractor / Funded Organisations
Warwick - HRI
Keywords
Environmental Protection              
Farming              
Integrated Farming Systems              
Nutrients              
Sustainable Farming and Food Science              
Sustainable Farming Systems