Evaluating heat tolerance of a complete set of wheat‐Aegilops geniculata chromosome addition lines

Abstract

AbstractHeat stress limits wheat (Triticum aestivum L.) yield potential in many areas of the world, and wild relatives represent an important novel source of genetic tolerance. In a previous study of various Aegilops species, an accession of Aegilops geniculata, TA2899, was reported to be heat tolerant. Prior to that, a complete set of wheat‐Ae. geniculata chromosome addition lines were developed using the same accession. The objective of this study was to screen the full set of addition lines to identify the chromosome(s) which carried the heat tolerance. The addition lines, Chinese Spring, as well as heat tolerant, and susceptible controls were screened twice for post‐anthesis heat tolerance in growth chambers. Genotypes varied for temperature treatment (p < .05), but no differences were found between Chinese Spring and the addition lines. Additionally, no genotypes were superior to positive controls for grain fill duration. The proposed reason is that the TA2899 which was previously identified as heat tolerant should be reclassified as Aegilops peregrina. This is supported by spike morphology and marker correlations using genotyping‐by‐sequencing. Despite negative results, the methodology is valid and the results remain important to report, if for no other reason than to prevent another researcher from investigating this question.