What is "hyperhydricity"

Hyperhydricity (previously known as vitrification) is a physiological malformation that results in excessive hydration, low lignification, impaired stomatal function and reduced mechanical strength of tissue culture-generated plants. The consequence is poor regeneration of such plants without intensive greenhouse acclimation for outdoor growth. Additionally, it may also lead to leaf-tip and bud necrosis in some cases, which often leads to loss of apical dominance in the shoots. In general, the main symptom of hyperhydricity is translucent characteristics signified by a shortage of chlorophyll and high water content. Specifically, the presence of a thin or lack of a cuticular layer, reduced number of palisade cells, irregular stomata, less developed cell wall and large intracellular spaces in the mesophyll cell layer have been described as some of the anatomic changes associated with hyperhydricity.