Dubautia species

Some wild species have larger capacities for osmotic adjustment, a trait which may improve yield during drought (Table 3, Turner, 1986). Interesting examples of this are Dubautia species from Hawaii which differ in osmotic adjustment mainly as a result of differences in cell wall elasticity. Interspecific hybrids can be made which have intermediate properties (Robichaux, Holsinger Morse, 1986). Material such as this could make a basis for the molecular study of differences in cell wall elasticity. 

Robichaux, R.H., Holsinger, K.E. Morse, S.R. (1986). Turgor maintenance in Hawaiian Dubautia species the role of variation in tissue osmotic and elastic properties. In The Economy of Plant Form and Function, ed. T. Givnish, pp. 353-80. Cambridge Cambridge University Press. 

Perhaps the most useful contribution made by flavonoids in this group of plants, however, was the assistance they provided in studies of natural hybridization between Dubautia scabra and D. ciliolata (Crins et al., 1988a). Dubautia scabra is a pioneer plant that colonizes new lava moderately D. ciliolata occurs on somewhat older lava. Where newer flows overlap older ones, one can often find plants with features intermediate between the two species. This phenomenon is readily observed in the vicinity of Kilauea Volcano on the island of Hawaii, where one finds D. scabra subsp. scabra on newer substrate and D. ciliolata subsp. glutinosa on the older substrate. Since the two taxa exhibit different flavonoid profiles, and we know that flavonoid profiles are inherited in an additive fashion, hybrids would be expected to exhibit flavonoid markers inherited from each parent. A major advantage in this study was the availability of known Fj hybrids that had been produced from controlled crosses at the University of Hawaii (by G. D. Carr). Analysis of the... 

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