Plant Growth Conditions and Yield of Viable Protoplasts Isolated from Leaves of Lycopersicon esculentum and L. peruvianum

Abstract

Protoplasts were isolated from leaves of the cultivated tomato Lycopersicon esculentum cultivar Rheinlands Ruhm and the wild species L. peruvianum which were grown under different environmental conditions. These conditions included different calcium concentrations in the root medium, treatment with abscisic acid and kinetin, and different temperatures and humidities. No consistent differences in final yields of protoplasts were found between control and plants treated with either calcium, abscisic acid or kinetin. The final yields, however, were significantly higher in plants grown under relatively high humidity (82 % relative humidity) and low temperature (15 °C) as compared with those grown under low humidity (56 %) and high temperature (25 °C). The increase of final yields was greater in the cultivated plants. Greater proportions of spherical as well as viable protoplasts as expressed by their plating efficiency, were isolated from plants grown under the lower temperature and higher humidity. Some of the changes characterize the leaves of plants grown under the different environmental conditions are discussed.