Genetic variation in anther extrusion in oats and its relationship to Fusarium

Abstract

Anther extrusion (AE) is a trait that has been studied in wheat for its influence on Fusarium head blight. Fusarium is a disease causing great problems in Nordic small grain production, particularly in oat. However, AE is little studied in oat. In this thesis the variation of AE was studied in RILs of two oat crosses, Svea × Stormogul and Fiia × Stormogul, and in a collection of 146 genotypes, mainly of Nordic origin. Both crosses showed high heritability for AE over two greenhouse experiments, and was estimated to be controlled by 4 and 6 genes respectively. The association between AE and other traits was assessed, with lemma color indicating linkage clearest. Two experiments with drought before anthesis gave lower AE in all genotypes exposed to drought. Variation of extrusion was not found between branches in the panicle, but between the 1st and 2nd florets. Neither the difference in swelling of lodicules nor the lengths of filaments seemingly cause differences in AE. The association between AE and DON was not convincing, but the percent florets with remaining anthers gave a ‘fan shape’ when plotted against DON. Emasculated florets infected with Fusarium graminearum indicated the same effect, with lowered DON level when anthers were removed.