It has been known that species diversity generally enhances the health of an ecosystem. Now, scientists (Reusch et al., 2005) who studied the seagrass Zostera marina in the Baltic Sea have found that DNA diveristy within a species can provide resilience to populations of the seagrass within an ecosystem.
It was found that the more genetic diverse populations of the species survived a heat wave better than a population of the same species with less diverse genotype. Not only that, epifaunal groups associated with the seagrass like juvenile bivalves, grazers like snails and isopods also benefitted from such intra-specific diversity.
Now wouldn't that have some implications for enhancing gene diversity within crops that tend to have low genetic diversity on account of focussed breeding for selected traits?
Summarised from (Frankham, 2005).
Frankham, R (2005). Ecosystem recovery enhanced by genotypic diversity. Heredity, 95, 183. News and Commentary
Reusch, T. B. H., A. Ehlers, et al. (2005). Ecosystem recovery after climatic extremes enhanced by genotypic diversity. Proceedings of the National Academy of Sciences U.S.A. 102(8): 2826-2831.