Genetic and environmental effects on the occurrence of speltoids in winter wheat cultivars

摘要

The occurrence of speltoid off-types during seed multiplication is one of the major causes for rejection of a wheat cultivar candidate due to phenotypic inhomogeneity. These aberrant plants express an atypical spear-shaped spike with tenacious glumes. To analyse the frequency of speltoids under field conditions, field trials were conducted at three locations and two sowing times over 2 years based on speltoid off-type spikes derived from 14 different wheat genotypes. One hundred single ear progeny were developed from the normal and speltoid progeny plants in 2007. A mean frequency of 21.1% and 36.6% speltoid off-types in plots from normal and speltoid lines was observed, respectively. Plots sown late in the season displayed on average 5.3% less speltoid off-types, in particular when both sowing times were far apart. Field trials from 2010 revealed 7.9% more aberrant plants compared with 2011. The percentage of speltoids within the field plots ranged from 0.2% to 83.7%, which indicates a large effect of the respective genotype. Finally, strategies to reduce the number of speltoid off-types are discussed