1. Resistance of wheat to septoria tritici blotch ( Mycosphaerella graminicola) and associations with plant ideotype and the 1BL−1RS translocation.
- Author
-
Arraiano, L. S., Brading, P. A., Dedryver, F., and Brown, J. K. M.
- Subjects
- *
WHEAT speckled leaf blotch , *FUNGAL diseases of plants , *WHEAT diseases & pests , *WHEAT powdery mildew disease , *WHEAT root rots , *WHEAT fusarium culmorum foot rot , *POWDERY mildew diseases , *MYCOSPHAERELLA , *PLANT epidemiology - Abstract
Septoria tritici blotch (STB) is a major disease of wheat, reaching epidemic proportions in many parts of the world. In several studies, taller, later-maturing cultivars have had lower disease levels. This study was undertaken to investigate the genetic associations of natural field infection by STB with disease-escape mechanisms related to heading date and height components, mainly leaf spacing, in a population where height and maturity are not controlled by major genes. In field trials of a single seed-descent population of a cross between two nonsemi-dwarf cultivars, Apollo (with strong partial resistance to STB) and Thésée (susceptible), conducted over 3 years, there was a negative correlation between STB and heading date. There was no correlation between STB and distance from stem base to leaf 2; and there was an unexpected positive correlation between STB and distance from flag leaf to leaf 2, which contradicted the so-called ‘ladder effect’ postulated in STB epidemiology. No effect was detected of the presence of the 1BL−1RS translocation on STB levels. The largest single contributor to variation in STB levels was genetic variation between the progeny lines, and the narrow-sense heritability was 42%. These results suggest that breeders can select for STB resistance alongside optimal stature within the range of height which is adaptive in a particular environment. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF