Quantitative trait loci for seedling and adult plant resistance to Stagonospora nodorum in wheat

Authors

Manisha Shankar, Department of Agriculture and Food, Western AustraliaFollow
Esther Walker, Department of Agriculture and Food, Western AustraliaFollow
Hossein Golzar, Department of Agriculture and Food, WAFollow
Rob Loughman, Department of Agriculture and Food, Western AustraliaFollow
R E. Wilson, Department of Agriculture and Food, Western Australia
Michael Francki, Department of Agriculture and Food, Western Australia

Document Type

Article

Publication Date

7-11-2008

Journal Title

Phytopathology

ISSN

ISSN:0031-949X e-ISSN:1943-7684

Keywords

Phaeosphaeria nodorum, pleiotropy

Disciplines

Agronomy and Crop Sciences | Biosecurity | Plant Breeding and Genetics

Abstract

Stagonospora nodorum blotch (SNB) caused by Stagonospora nodorum is a severe disease of wheat (Triticum aestivum) in many areas of the world. S. nodorum affects both seedling and adult plants causing necrosis of leaf and glume tissue, inhibiting photosynthetic capabilities, and reducing grain yield. The aims of this study were to evaluate disease response of 280 doubled haploid (DH) individuals derived from a cross between resistant (6HRWSN125) and susceptible (WAWHT2074) genotypes, compare quantitative trait loci (QTL) for seedling and adult plant resistance in two consecutive years, and assess the contribution of QTL on grain weight. Flag leaves and glumes of individuals from the DH population were inoculated with mixed isolates of S. nodorum at similar maturity time to provide accurate disease evaluation independent of morphological traits and identify true resistance for QTL analysis. Fungicide protected and inoculated plots were used to measure relative grain weight (RGW) as a yield-related trait under pathogen infection. The lack of similar QTL and little or no correlation in disease scores indicate different genes control seedling and adult plant disease and independent genes control flag leaf and glume resistance. This study consistently identified a QTL on chromosome 2DL for flag leaf resistance (QSnl.daw-2D) and 4BL for glume resistance (QSng.daw-4B) from the resistant parent, 6HRWSN125, explaining 4 to 19% of the phenotypic variation at each locus. A total of 5 QTL for RGW were consistently detected, where two were in the same marker interval for QSnl.daw-2D and QSng.daw-4B indicating the contribution of these QTL to yield related traits. Therefore, RGW measurement in QTL analysis could be used as a reliable indicator of grain yield affected by S. nodorum infection.

Recommended Citation

Shankar, M, Walker, E, Golzar, H, Loughman, R, Wilson, R E, and Francki, M. (2008), Quantitative trait loci for seedling and adult plant resistance to Stagonospora nodorum in wheat. Phytopathology, 98 (8), 886-893.
https://library.dpird.wa.gov.au/bs_research/92