Items from the United Kingdom.

ITEMS FROM THE UNITED KINGDOM


JOHN INNES CENTRE

Norwich Research Park, Colney, Norwich NR4 7UH, United Kingdom.


Genetic biodiversity for yellow rust resistance in U.K. wheat cultivars. [p. 98]

Lesley A. Boyd, Clare Lewis, James Melichar, Luke Jagger, and Nicola Powell.

A number of programs are continuing to characterize the genes/QTL responsible for yellow rust resistance in UK wheat cultivars, including the UK cultivars Claire, Guardian, and Brigadier. Genetic mapping is utilizing SSR, AFLP, and NBS-based PCR marker systems to identify partial, adult-plant expressed resistance towards the fungus P. striiformis, the causal agent of yellow rust. Yellow rust resistance genes/QTL identified will be located across a diverse range of UK wheat cultivars, both current and historic, that are representative of the current winter wheat germ plasm pool utilized by UK wheat breeders.

Genetic biodiversity studies also have been extended to include an assessment of Turkish wheat cultivars (durum and bread) as part of a collaboration with Prof. M. Sayar, Bogazici University, Istanbul (EU­Marie Curie Fellow) and CIMMYT in Ankara, Turkey, and Mexico. NBS-profiling has been used to characterize the genetic diversity associated with NBS (R-gene) sequences within the wheat genome. The Turkish cultivars are being compared to a selection of 30 wheats from across Europe.

 

Novel sources of resistance to biotrophic fungal pathogens in wheat. [p. 98]

James Melichar and Lesley A. Boyd.

A number of mutants, generated by g-radiation in the UK wheat cultivar Guardian, were selected originally in the field for enhanced resistance to yellow rust. This enhanced resistance was shown not to express in seedlings but to be developmentally regulated, expressing at adult-plant growth stages.

In addition to the enhancement of resistance to yellow rust, a number of the mutants also exhibit enhanced resistance to leaf rust and/or powdery mildew. Doubled-haploid populations have been developed in Guardian and two of the mutants. Having identified the QTL for the partial, APR to yellow rust in Guardian, the mutations responsible for the enhancement of yellow rust resistance will be mapped. These populations now form part of a European Union-funded program BioExploit.

 

Factors affecting yellow rust infection efficiency in wheat. [p. 98]

Ruth MacCormack and Lesley A. Boyd.

A Defra-funded program examined the early stages of P. striiformis infection to determine what environmental factors influenced infection efficiency of this fungal pathogen. The quanta of light received by wheat seedlings and preinoculation by the pathogen, influenced the ability of P. striiformis to find and enter stomata. A preliminary screen of a small number of wheat cultivars showed genetic variation between wheat genotypes for the ability of preinoculation light quanta to effect P. striiformis infection efficiency.

 

Nonhost resistance in wheat and rice. [p. 99]

Hale Tufan and Lesley Boyd.

The CGIAR Generation Challenge Program project 'Cereal Immnity' consists of a collaboration between seven research groups around the world and is lead by AGROPOLIS, Montpelliar, France. The program uses the Affymetrix wheat micro array to study gene expression in wheat in host and nonhost pathogen interactions and links in with similar studies in rice being carried out by Prof. P. Ronald, UC Davis, USA, and Prof. S. Kikuchi, NIAS, Japan. Initial microarray screens have identified a number of common transcripts that are up-regulated in wheat and rice in the nonhost-pathogen interactions.

 

Publications. [p. 99]

  • Boyd LA. 2006. Perspective: Can the durability of resistance be predicted? J Sci Food Agric 86:2523-2526.
  • Boyd LA, Smith PH, and Hart N. 2006. Mutants in wheat showing multi-pathogen resistance to biotrophic fungal pathogens. Plant Path 55:475-484.