The relationships between plant developmental traits and winter field survival in rye (Secale cereale L.)

Citation

Bahrani, H., Båga, M., Larsen, J., Graf, R.J., Laroche, A., Chibbar, R.N. (2021). The relationships between plant developmental traits and winter field survival in rye (Secale cereale L.). Plants, [online] 10(11), http://dx.doi.org/10.3390/plants10112455

Plain language summary

The ability of winter cereals to overwinter is a very complex issue. However the cold acclimation conditions during the fall will help winter cereal to get ready to survive to the upcoming winter freezing conditions. Fall rye is the cereal being able to develop the highest level of freezing tolerance. In this study we examined a panel of 96 genotypes of rye of different origins and growth habits in function of winter field survival, low temperature tolerance, and six other developmental traits. Results show very strong correlations between winter field survival and low temperature tolerance (r=0.90) and between winter field survival and final leaf number (r = 0.80). We postulated that the plant adaptation to low temperature is regulated by the phytohormone levels at shoot apical meristem.

Abstract

Overwintering cereals accumulate low temperature tolerance (LTT) during cold acclimation in the autumn. Simultaneously, the plants adjust to the colder season by making developmental changes at the shoot apical meristem. These processes lead to higher winter hardiness in winter rye varieties (Secale cereale L.) adapted to Northern latitudes as compared to other cereal crops. To dissect the winter-hardiness trait in rye, a panel of 96 genotypes of different origins and growth habits was assessed for winter field survival (WFS), LTT, and six developmental traits. Best Linear Unbiased Estimates for WFS determined from five field trials correlated strongly with LTT (r = 0.90, p < 0.001); thus, cold acclimation efficiency was the major contributor to WFS. WFS also correlated strongly (p < 0.001) with final leaf number (r = 0.80), prostrate growth habit (r = 0.61), plant height (r = 0.34), but showed weaker associations with top internode length (r = 0.30, p < 0.01) and days to anthesis (r = 0.25, p < 0.05). The heritability estimates (h2) for WFS-associated traits ranged from 0.45 (prostrate growth habit) to 0.81 (final leaf number) and were overall higher than for WFS (h2 = 0.48). All developmental traits associated with WFS and LTT are postulated to be regulated by phytohormone levels at shoot apical meristem.