Hyperhydricity reversal and clonal propagation of four-wing saltbush (Atriplex canescens, Chenopodiaceae) cultivated in vitro

Abstract

In vitro propagated shoots of four-wing saltbush (Atriplex canescens, Pursh Nutt) showed severe symptoms of hyperhydricity. We show that the reversion of hyperhydric A. canescens shoots to normal shoots was significantly affected by the presence of inorganic nitrogen in the culture vessel. When the culture vessel was vented or when ammonium nitrate was deleted from Murashige and Skoog basal medium, rates of reversion were significantly higher. Although statistically significant differences were evident when comparing vented v. non-vented treatments for each medium, the modified culture medium with vented closures was consistently the best treatment, showing a total cumulative frequency of 39.7% reversion to normal morphology, compared with a total cumulative frequency of 7.1% observed in the control treatment. Resulting normal shoots also showed significant improvements in further manipulations, including rooting in vitro, transplantation to soil and survival in native sites.