leipner photosynthesis consulting

Tolerance to frost is essential in wheat with rapidly fluctuating winter temperature in a changing climate. The goals of a study conducted at ETH Zurich were to characterize wheat accessions with contrasting frost tolerance and to investigate the suitability of chlorophyll fluorescence and leaf greenness traits as selection criteria for winter hardiness (PhD thesis Plasse). Wheat accessions were grown under field conditions without snow cover at the altitude station of INRA Dijon in Chaux des Prés (France). Maximum quantum efficiency of PSII primary photochemistry (Fv/Fm) and leaf greenness were determined throughout the winter seasons. There was a large variation in winter hardiness within the investigated material. The determination of Fv/Fm in combination with leaf greenness permitted a differentiation of the accessions in respect to their winter hardiness already at the beginning of the winter. A distinct grouping of the investigated plants with regard to their ability to maintain frost tolerance was revealed by an analysis of the time course of Fv/Fm.

Screening wheat seedlings for frost tolerance under field conditions