Morphological and Physiological Studies Concerning the Drought Tolerance of the Secale cereale × Secale montanum Cross Permontra

The root morphology, drought tolerance and heat tolerance of the S. cereale × S. montanum cross Permontra , six cultured S. cereale varieties and the wild rye S. montanum were investigated and the use of membrane stability tests as a selection tool for drought and heat tolerance in rye evaluated.
Root length, surface area and lateral density were measured on plants at the three leaf stage. Tolerance to drought, acute heat and chronic heat stress heat was assessed in culture chamber tests on control and drought or heat conditioned potted plants and membrane stability assessed by measuring electrolytic leakage.
Permontra had the most extensive root system and was the most drought tolerant variety measured. Permontra was also the most tolerant of the varieties to chronic, though not to acute, heat stress. There was no correlation between drought tolerance in potted plants and membrane stability following either heat or dehydration stress.