Halophytes for Bioremediation of Salt Affected Lands

Abstract

The area of secondarily salinized lands is increasing at a faster rate over time. Many irrigation districts around the world are shrinking as a result of secondarily salinized soils. This is resulting in crop yield losses. Irrigation practices with low drainage are intensifying this problem. Bioremediation of salinized soils with halophytes is one of the means of reversing this process. In these studies, we tested the growth and performance of four salt tolerant halophytes to varying levels of salinity. We analyzed the salt content of the plant tissues at different salinities, in order to determine how the plants' tissues reflect the increases in salinity. It was discovered that Allenrolfea occidentalis tolerates and grows well at higher salinities than the other plants tested. Furthermore, the concentration of salt in the aerial plant tissue was high and increased further in response to the external salt concentration. Halophytes such as A. occidentalis can be used to remediate abandoned salt affected lands and their biomass can have an added economic value. On the other hand, domestication of wild halophytes for agronomic purposes represents another opportunity to address the increasingly salinized soils and shortages of freshwater around the world. In these studies, we assessed the potential for improvement of an oilseed halophyte, Salicornia bigelovii, through selective breeding. We compared plant characteristics of S. bigelovii cultivars produced in breeding programs with wild germplasm in a green house common garden experiment. We concluded that S. bigelovii has sufficient genetic diversity among wild accessions and cultivars to support a crop improvement program to introduce desirable agronomic characteristics into this wild halophyte.