Propagation of Prunus and Malus by temporary immersion

Abstract

Temporary immersion, solid and liquid culture methods were compared to evaluate in vitro propagation of three Prunus species and a Malus rootstock. The growth of plants cultured at 30 and 60 minutes of immersion per day was compared to that in solid and stationary liquid conditions. After 60 days, multiplication rate, water, chlorophyll, carotenoid and fructose contents were evaluated. Stationary liquid culture negatively affected plant growth by reducing multiplication rate, chlorophyll and fructose contents and by inducing hyperhydricity and necrosis. The multiplication rate did not differ on solid medium and in temporary immersion, but hyperhydricity was present to a certain degree on solid medium but never in temporary immersion. Moreover chlorophylls, carotenoids and fructose, in the form of sucrose, increased in temporary immersion, particularly at the optimal immersion time. The accumulation of sucrose and the increase of photosynthetic pigment content could be due to a partial restoration of autotrophic activity.