Miscanthus response to combinations of salinity and drought

As mentioned a couple of days ago, there’s a big push to try growing biofuels on marginal land. “Since irrigation of biomass crops is unlikely to be economic, it is important to identify genotypes that optimize the use of water in different climatic regions and those that are tolerant to salinity and water-deficit stresses,” said Stavridou and colleagues in their paper Novel Miscanthus genotypes selected for different drought tolerance phenotypes show enhanced tolerance across combinations of salinity and drought treatments. In their study, they compared three Miscanthus genotypes to see how they reacted under a combination of stresses.

Understanding how salinity affects Miscanthus could help improve its productivity. “Salt stress reduces the rate of photosynthesis due to stomatal limitation or non-stomatal effects,” said Stavridou and colleagues. “These include decreased chlorophyll content and leaf senescence related to the accumulated ions… and alterations in leaf photochemistry and carbon metabolism…”

The team compared M. floridulus, M. × giganteus and two varieties of M. sinensis to see how they reacted to single and multiple stresses. It should be no surprise that multiple stresses caused more problems than a single stress. The authors said, “. The high-yielding M. × giganteus and M. floridulus genotypes produced more yield under all treatments than the slower-growing but more stress-tolerant M. sinensis genotypes.”

The team conclude that while the higher-yield Miscanthus species are less tolerant, they may still be the source of superior biofuel material.